JOURNAL OF RESEAR CH of th e Notional Bureau of Standards-A. Physics and Chemistry Vol. 75A, No. 2, Marc h ~ Ap ril 1971
Crystal Structure of Ca 2 Na 2 (C03 )3 (Shortite)
B. Dickens, A. Hyman, * and W. E. Brown**
Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234
(December 18, 1970)
Ca, N",(CO"h cryS la lli ze, in I he o rl hnrhombic un il ce ll (f = 4.947( I ) A. /) = I 1.0:)2(2) A. a nd (" = 7. 108( 1) A al 2S oC wi lh 111'1) formul a weip:ll is in s l' aee·p:rtlup Am 1ll 2. Th" , Irue lu re has been J"( ·delcrm in ed. ("o ITeel,·d. a nd rdined 10 /? ".= 0.02S . /? = 0.020 u s in ~ 684 "ol,,;erved" x· ray reflec li ons f rom a s ill ~. .d(' ('ry!-' I al. Corrcctions w('r(' m uck ror a bsorption a nd isol rllpic t'xlinclioll . III the t'xtinc tio n refin e me nl s, ,. refin e d 10 0.000]7(1) C Ill. The structure consists of Ca,NaCO" layers inte rl eaved with Na(CO,,), laye rs . T he Ca ion is coordin a led sl r o n ~ l y 10 nin e oxygcns, in c ludi,;g Ihree LO" edges, wilh Ca .. . 0 di s lalHTs varyin g from 2.40 1(2) ;\ In 2.S76(2) A. One Na io n is cuurd in a lcd sl ronp:ly 10 e ighl oxyp:cns , In c lud ing 111'0 CO" e dges. wilh Na ... ° rii sla n.ops from 2.429(2) A1 02.605(1) A. The 01h e r Na io n i, coordi nal(' c1 slrun;;!y In six ox y~ en , . incilidi np: one CO" edp:e . a l 2.296( 1) A 10 2.414 A. a nd wea kly 10 a sevenlh a l 3.050(3) A. One CO" P: r ~ ('y words : Calci um ~o dilllll ca rbonat(': cr ys tal :-; trtl C' tul"(': shortit e: sin :,r k -(' r ysl al x-ray diffracti on, 1. Introduction fr agment from mine ral sa mple 105807, National Museum of Natural Hi sto ry, Smithsoni an InstituLion, As part of a progra m of s tudies [1 , 2J I 10 obtain pre Washington , D.C. (sample s uppli ed by J. S. White, Jr. ). cisc Slructura l parame le rs on calcium carbonates, The sphe re was mounted on Ih e go ni o me te r head in ca lcium carbo natc hyd r ates, calciu m phosphal es, a nd ou r usua l way r2]. re laled co mpounds, we have re in vesti gated Ih e crystal formu la (id eal): Ca~ Na~ (C01 h structure of Ca~Na~(CO : lh, whi ch exists in nature as cell: orthorh ombic the min e ral sho rtite. The s truc lura l fealures in these a, = 4.947(1) A compo unds are import ant in the cons id eration of pos b = 11.032(2) A sible e pit ax ial, syntaxial, a nd substitu tional solid solu c = 7.108(1) A tion. re lali onsh i ps in I he majo r ino rganic phases found vo lume = 387.9 A.:l in VI VO. s pace-grou p A mm2; S ho rlil e was firs t found [3] in a matri x of montmoril cell conte nts 2 [ Ca~Na2(C0 3h ] lonite clay whi c h also contai ns pyrite (FeS~), calcit e reciprocal lattice extin ctions : k + l = 2n + l for (CaCO:1) , and a carbonate of magnesium in c rys tals hkL ; which were too s mall to be ide ntifi ed. Massive de posits calculated density 2.620 g' cm-:l; 3 of the commerciall y important mineral trona (Na~C O :l . observed density 2.629 g ' c m- [3]. NaHCO:1 · I-I ~ O ) are also found in the vicinity. A c rystal The procedure given in reference [2] was followed structure for s hortite has been reported by Wickman in the collection a nd processin g of data with the follow [4], who s uggested ato mi c positi ons on the basis of ing exceptions. The &--28 scans were carried out at refracti ve indices, spati al considera ti ons, a nd the 2°/ min. Eac h background was counted for 20 s. 1659 intensiti es o f the OkL re fl ections. Wc found this struc reflec tio ns we re coll ected from the Ilkl a nd hkL octants ture to contain one in correcl feature. The corrected and were me rged in to a unique set of 711 , of which structure of shorlil e is re ported here. 684 a re "observed" and 27 are " unobserved." The R fa c tur be tw een observed equivalent reAecti ons was 2. Data Collection and Structure Refinement 0.01 . No absorption corrections were made because the maximum e rror in an inte nsity due to absorption The crys ta l used in the data coll ecti on is a n approxi is 0.8 pe rcent. For Ca~Na~(CO:lh, f-t (Mo) = 15.7 c m ~ l. male s phere, radius 0.112(4) mm , ground from a s hortite The Picke r ~ hardware dropped the least s ignifi cant "! Certai n cO lllmercial ('quipmt'llt. in s truments . or ·materials a rc ide ntified in this p aper *Dl'part 1!l t.: ll t of CIH'llIi .-.; t r y. Ulliversity of \ \ary\alld Bah illlnrt.' C nllnlY. Bctltimon'. Md. i ~ l or.der to specify the experimental procedure adequately. In no case ri oes s uc h id e nt iftca ** Din,(· tol". Arn eril" an Dental As~ol"iatioll H t.:~t'a r (' h Pl"Ogralll. National Bu reau of S tand· tilin Imply recom mendat ion 01" endorsf' me nt b y the Nat ional Bureau of S ta ndards . nor does arcls. Washington. D.C. 20234. it imply that the material or eq uipment ide ntified is necessarily the best available fo r the 1 Fi )! III"e:'!' ill br a(" k( , t ~ indicate t hl' lit. 'I" TABLE 1. Atornic parameters of Ca,Na'(C03 h (0) Atoms x y z 8 11* 8" 8"" 8 " 8,,, 8", Ca e, fII, 4 0.5 0.21659(4) 0.0 0.65( I) 0.43 (l) 0.53(1 ) ...... - 0.01(1) Na(l) (/ , 111m, 2 0.0 0.0 0.9263 (3) 1.27(6) 0.97(5) 1.54(6) ...... Na(2) Ii , 1I11ll, 2 0.5 0.0 0.6122(3) 1.15(5) 0.69(5) 1.15 (5) ...... C( l) d , m, 4 0.0 0.2961 (2) 01697(3) 0.57(6) 0.34 (7) 0.64(5) ...... - 0.04(5) 0(1) d. m , 4 0.0 0.1 935 (2) 0.0742(3) 1.03(6) 1. 35(7) 1.44(7) ...... - 0.31(6) 0(2) j~ 1, 3 0.2261 (3) 0.3456(1 ) 0.2152(2) 0.59(4) 1.02(4) 1.03 (4) - 0.19(3) - 0.04(3) - 0.02(3) C(2) b l mm, 2 0.5 0.0 0.2253(5) 1.1(1) 0.58(3) 0.64(9) ...... 0(3) b, 111111, 2 0.5 0.0 0.0415(4) 1.7 ( 1) 0.60(7) 0.6 1(7) ...... 0(4) e, 111 , 4 0.5 0.1013(2) 0.311 I (3) 2.10(7) 0.57(5) 0.99(6) ...... -0.23(5) Figures in parentheses are standard errors in last significant figure quoted, and were co mputed in the final cycle of full-matrix least squares refin ement. " Wyckoff sy mbol, sit e SYllImetry, and multiplicity of sit e in space·group Alllm 2. 'Thermal parameters ha ve th e form exp (- 1/4 ((f *" 8 "I!' + b*'8,,1, , + c"' 8;"d' + 2a *h' 8 "I!k + 2(1 *c '; B,,,h/ + 2b*c* 8 ,jel» . 130 TABLE 2. Observed and calCI.Ila led Sll"II clflrej(lctarslar Ca,i\'a,(CO"h (s horlile) 0170 114 II'H ttl 115 1111 915 'i 192 192 I I" I 11118 1229" 3 120 1 200 )0 'J6l 386126 S .J O, l I!I 6) 66 2 11 12 1" 2 1"5981 1 H ie 2 1 6" ) 9 182 lin 93" 510 666l 0 1<)1 190 0 1 250 252 9)5 5'1 5692 .. 0 168 16'1500 o 1500 2 ~I" 529 188 10 12 69 906 '" 950 .. ~ I ~ 5 19 116!> 2 1'" 1 .. 7 909 9 11 6 118 91" 31 2882' 2 11 . Q 11\" 2 1"2 1"2 90 .. 6 21 1 2 11 55 095 !lb 500 .. 132 III <)99 II 131 I'" 936 9 " 91118 .. l oS 16320 llAI I A" 9'i2 .. Jl :)12'" 8171 1155)) 1'''5 31'' 30 2 2S1 251 6 1 091 93 500 & 90 8'> 21 3 2 13 21 1 "6 t> 10i 100 860 I 0 2~1 261 )(1 1115 17992" ) 266 2n 821 I q l 5(10 " 210 2 75 971 2 112 ll" 951 8 131 Il" 691 5 1" 16 970 12161 159119 1 '169 111 12J ~ 323 )23 60J 221" 2 1 0 'i3 b 205 20b 58 "16 2 18) IJJ 121"1n l099" 2 5 111'1 II!I O 9~5 1 2 10 21ij 912 ~ 20;> 202 t> Il 90 8~ 808 I 1"1 I~ O 0 1 6 1&" 102 91b o J1 9 0 0 1 .. 1\ I..," 500 1 2 19 2 1 55!1 1 l59 2b l 9'9 9 1~ 5 1,,0 919 " I ~ I 1,, (1 9 q 6 10 102 102 f\ I ~6 I~ I 915 2,,02 " 05 25 2 75 8" 9)1 201 99;> J IIJ 11 961 .. 9120 12198' II "3 \Jl IA 8 2 ~ Q ;>48 952 10 106 10) 80 .. 110 6 1950 .. 1'18 198911 ':> 19" 191 '1 3 8 I 29') 291 888 6 100 1112 9~ 5 ) 86 8 1 992 " 0 )6110 hlI1915 0518 5 78500 81"" 1"5 3 0 5 108 10 l\9:J I 11 ~ 6 I " " 5 100 'H 12 I JUS )1" 9)l 2 1"8 1"9 1) ]0 12 1 ]1 2 110663 A. " 12 1125 125212 0", ' 5501) 3 01 500 J ,28 5"0 91 .... 50 32 2 7" 95& I 5l 51815 5" ... 0 ~ I , " "5" .. 930 BO 18500 9 " 1 } 9 9 .... 2 2~) 2 .... 500 "9~ 12 3 5 l J 12 8 1~ b )03 308 962 J 126 12A "5 3 120 122 9'1 , " 99 I OU A20 11 110 22l .. 5 .. 111 t bJ 26 .. 2f1 .. 2AI 6 5 I ~ A 14" 3" 1 J o l 362 9 " 5 8 31" 311 929 "' 11 2 112666 018 II() 0 ~2 J II 81 1 b 25 1 252911 o 1"5 I n l ", 12' . 3' 1 <;" 9 20" 20 ~ '1)6 102"52"9 59 1 I"" I b ~ 695 I J 93 "00 'Ill I!I 12 1 12" 50 A ~06 llO 9" ~ II olOO 198 938 12 90 86 81 .. q 108 10'1 '115 3 JI 9 )22969 2 175 11590J o 2)' 2 " 85 1 117 8JO 10 11 5 II" 8 52" 2)" oj 0 158 15 \ 500 .. 180 1809" 1 I IfI' Ifll 95) 0"81 '>29500 76" 8367J 2 281 298 9&~ 6 10" 10690" ) 771"1 ?f,7 9~ I "I 9 .. ' ., I I I< II" 9'16 2 ~Oll .. 0510 1 o l !!o<; IA'i 0 9120 120 I!> ~ 26') 2"7 92 5 .t ) , L 1 IJ;> IB 10 I Ib l 161 80 ~ ~90 "9&9111 222 1 ;>719;>" o 12~ 122 0 I IJ:J III 926 o ,& 0 11 " CUI "2f12 28 1 <)25 6 }90 '9J l8 18l/l"1 .. 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'5 ll" III 91J 2 JOO H 28PJ 02,0227 II 'J 6' 6" '1'5 .. 2J" 2 " 950 1199191\ Q"I\ '1G'l13 1\ 20;> ;>11" ql"., .. 250 ;>J9 19f1 2 I ~I 1'2 91'1 II c,<; c,,, Q~6 .., 2 15 2 1" l5 J I Al 18" 9 ~ b l"l 3'1 991 0312 H5 \.I 6 '19 J2" 9 111 " 15' 1':>2 ql'lJ J 2 11 2 1" 11'1 tlIO'l I Obo.;" 3 5 "'18 " 95 5 .., l OS 10 ) 17b 2 21111 199 25 II l(,~ 10" 15 J .J 31>1 H I Q19 12 .... 2"" I b "81 71\ 22(1 15" 991 12n 500 1 II J 609"2 ;>1") In J 1"9 I~.. 6':> 1U II I IUb 808 5 318 3 19 2 267 JA (I I 'i~ 1115 1 1"691l 8 ~9 "b l AG 5 ' S2 J57 Q99 .. 16S ]6'i .., 8f, '12 "" 5 19 ' II ':19" 1 1'10 189 15 & 21'1 21 'I '1t1~ , I PS 121 9 .... q 176 11' 92'1 , "9~ "'11 ] 'I 1 1"5 0213212500 .. '22J 22J 98'> 11 IL l 11)91'1 .. H] 31'i 29 J 180 182 115 2 129 121 9 102 103 7 8111 ]15 " b 3"1'i H19'17 ,230239 12 " 1 !>22 516 '11 '1 11" 1M 6 1 4382J o 10 02 0 I IJI 1"0 '14, Ibl IS::. 0 I", 1)0 29 J 2'17 280 .. 11 I ~ 2"3 ;> .. 0 II .... 1..) 53 2 215 273 I\~" 'IJO 1)0 ~1 o 9A I on 0 52:n 291 '5 o 2 17 2 16500 1220" ;>11'191 1 .. 5 1 3b 15 091510 )) 0 5 I~' 1"6 951; 01'58 U I 160 15'1 1\1 283 1'> lbl J 110 11201 2 ]Q" 1'159119 72'0 22169" 2 50 J'i , o I .... I .... 1\10 ;> 21b 213 112 120b 1989":;' " "201 ;>~8 Q~':> J':>" 9J7 ,. 2 1b 2 1Q '10 851 "91\20 .. 29 1 29" 951 9 10~ 102 961; .. 122 121 890 5101 no, n2 9 '52 1100 Q5110) IIIJD 1219'12 & 1&1 15<; 951 o 2111i 28'1 II 101\' 19817 "Ilb 17" 31 & 51 5" 2 1 b 12" I?"'i 977 o 607 6J9 500 S 1&1 16? 9)0 I C,S .. 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In2 18h " I 859'1 II 50 " 6 Q'i .. 2"1 2")932 'i9Q .. ,) 2' 21S 22 1 927 6 II J3 1\"1 2 222 2 1 ~ 0 1 b IQ ' 16 '132 7 bO o~ MO 207 959 '" 153 I ..... 93'1 .. Ib5 I&ll SJ ~ 2119 29" 915 622· 26 SO Q III 1 1&992 fl . ")5110 2b 8 1"2 Ih2 91A .., i58 256 9 4 .. . 6216281 2" 0'06 0 I;> ~ 9 0 7 2 1 ' 2b 2 1 ~ ) 10 "1 I IlQ Q<;O t[I I J& 1l!> 962 Q 1'" I ~ 8 950 2201\ 20& 5' o 12" 'III SUO 1"11 10 19 1 I 'll A82 .. 191 19" '1211 52J'; ;>' 3 'l'IO I) 21(,4AJ081 .. 3 39~ .. 0 1 '112 6121 118 ", Ilij ' 1"6 C"lumns are I, ]01'"" , 10Fe a nd phas,· in millieyeles. "Unobserv ed" re fl ecti o ns are marked by *. The F,. valu es do not in clud e correcti"ns for exti ncti on. F" a nd F,. a re 0 11 all a bsolute scal('. FtGU RE 1. The crystal structure oICa2Na,(CO"h. shortite, viewed along a . The origi 11 of I he coordi nat e sys tem is marked by *, 131 F'GURE 2. As inJigure I but viewed along c. 3.1. The Calcium Ion Environment static attraction in the crystal. The Ca ions are about 4 A apart in the structure; the shortest Ca ... Na The Ca ion lies on a mirror plane at x = 0.5. Its distance, with associated weaker electrostatic repul environment is shown in figure 3 and summarized in sion than Ca . . . Ca, is about 3.5 A. table 3. The coordination contains three CO~ edges, 3.2. The Na Ion Environments 0(1', 2[) , 0(1 , 2) and 0(3, 4), and three C0:1 apexes, 0(2"), 0(2"') and 0(4'). T he Ca . . . 0 di stances There are two crystallographically di stinct Na ions in indicate strong ionic bonding from Ca to all these the crystal structure. N a(2) a nd Ca li e in the same plane oxygen atoms and are in the normal range. Strong perpe ndic ular to [100]. Na(l) lies halfway between the coordination to nine neighboring oxygens is rare for planes containing Na(2) a nd Ca. Both Na ions li e at the Ca and is possible here because of the small 0 ... 0 intersections of mirror p lanes. separation ( ~ 2.2 A) in the edge of the CO:1 group. A Na(l) is coordinated (fig. 3 and table 4) to eight oxy large coordination numbe r for Ca is favored by the ge n atoms, of which 0(2[11, 2[ V) and 0(2V, 2V') are C0 Ca . .. 0 interac tion being the strongest electro- 3 edges. All the Na(l) ... 0 di stances are within the normal range and indi cate strong ionic bonding. The co TABLE 3. The calcium environment in Ca2Na2(CO:1h ordination is similar to that of (i) the Ca ion CaNa2(CO:1h ' 5H20 [9], where the oxygens not in shared edges are Atoms Di s ta nce in water molecul es, and (ii ) the Ca(l) ion in Ca,, (P04 )2SiO" [10]. A TABLE 4_ Ca. 0 (4) 2.401(2) Ca. 0 (3) 2.4 110) Atom s Di sta nce Ca. 0 (2, 2'. 2" . 2"') 2.508( 1) Ca, 0(1 , I') 2.543(1) A Ca.0(4') 2.576(2) Na(l). 0(1. I') 2.429(2) Nai l ). 0(2"'. 2". 2'. 2"') 2.5:10(2) Na(1). 0 (3.3') 2.60.1 ( I ) In a ll tables of interatomi c di stances a nd anf!les . 'he quantities in pare ntheses a re sta nd ard e 'Tor, in the la st s if( nifi c a nt f i ~ uf'{ ' and Na(2 ). 0 (2" . 2" '. 2". 2''') 2.296( I ) we re com put e d from the sta ncl ard error, ill the atom ic pos itional Na(2). 0(4. 4') 2.414 (.')) paramete rs a nd in the cell parameters. They in c lu de c;o ntrihutions .'-J a(2). 0 13) :~ .0.50 (3 ) frum the vari a nce co-variance ma tri x. The atom la be ls refer to a toms in Ilf!ure 3. T he a tom la bels refer to atoms in ~gur e 3. F[GURE 3 . The Ca and Na environments in Ca,Na, (CO"},, . The pri mes refer 10 atoms in tables 3 and 4. 132 Na(2) is bonded s trongly to s ix oxygen atoms (table 4) TABLE 5. The Carbonate Anions and Their Environ essentially arranged in a s quare pyra m id with a C O:l ments CazNaz(CO:lh s hare d edge 0(4,41) centered about the apex posit ion (fig. 3). The e nvironme nt of Na(2) is completed by Atoms Disl a nee. A. 0 (3), whic h is, however , 3.050 A away a nd thus bonded or anglp deg. re latively weakly to Na(2). The geome try of strong co ordination for Na(2) is like that of Na(2) in Nat C 0 3 • H 2 0 [11]. C(1 ). 00) 1. 273(3) 'J.. C(I ). 0(2. 2') 1.286(2) OIl). 0 (2. 2') 2.211(2) 3.3 The CO:l Groups and Thei r Environments 0 (2) .0(2') 2.238(2) O( I J. CO). 0 (2 . 2' ) 11 96(lJo The dimensions of the CO:1 groups are given in 0 (2). C(l ). 0 (2') 120. 9(2) table 5. The C(I) CO:l group is nearly trigonal with an a ve rage C - 0 di s tance o f 1.282 the C(2) CO:l C(2).0(3) l.306(4)'J.. A; C(2). 0 (4. 4' ) 1.273(3) group appears to be s ignifi cantly non-trigonal, but with C(3). 0 (4. 4') 2.218(3) an average C - 0 di stance of 1.283 A. The average 0(4).0(4' ) 2.235(4) C - 0 di s ta nces co mpare we ll with 1.283(2) A in calcite 0 (3). C(2). 0 14. 4') 118.7(2)° 0 (4). C(2). 0(4' ) 122.7(3) (CaC03) [I2J, 1.285 A in aragonite (CaC03) [2J, 1.286 A in Na2C03· H 2 0 Ill], 1.288 A in CaNaz (C O oh . 5H zQ O(l). Na( I ') 2.429(2) A [9], 1.286 A in CaNaz (CO:J}2 ' 2HzO [9J , and 1.286 A 0(1 ). Ca. Ca' 2.54:3I lJ in CaCO:l · 6HzO [IJ. A ll th ese di stances are un cor rected for thermal motion. 0 (2). Na(2) 2.296( I ) The e nvironme nt s of th e CO l groups are s hown in 0(2). Ca" 2.508(1) 0(2). Ca'" 2.508(1) fi gure 4 and are s ummarized in table 5. All three edges 0(2). Na(l) 2.530(2) of both CO:1 groups are coord inated , in both cases to 0(2).012") 2.709(2) two Ca ions and one Na io n in the same pl ane as the COl group. All oxyge n atoms a re furthe r coordinated: 0(3). Ca 2. 411(1 ) 0(3). Ca" 2.4 11(I ) 0 (1) to Na(l ) in th e plane of the C(I ) C O l group, 0 (2) 0(3). Na( I ). ail' ) 2.605(1) to Ca and Na(2) both out of thi s pl ane, 0(4) to Ca(1) in 0(3). ' a(2) 3.050(3) the plane of the C(2) C O:l group, a nd 0 (3) to tw o Na(I ) ions whi c h are both out of this pl a ne. Edge coordinati on 0(4). Ca" 2.401 (2) 0(4). l a(2) 2.4 14(3) of 0(3, 4) a nd 0(3, 41) to Ca is expected to decrease th e 0 (4). Ca 2.576(2) 0 (3)- C(2)- 0 (4) a nd 0(3)- C(2)- O(4l) a ngles in accord with P au lin g's rule because the 0 (4. 41) edge of th e same CO:l group is coordinated with weaker electro The a lom labels rd"r III atom s in fi p: Llre 4. s ta ti c force to Na(2). This is in accord with the observed O- C- O angles of 118.7(2t for the Ca coordinated C a . 0 . 0 (2) di stances is 2.526 A. The diffe rence of edges a nd 122.7(4t, for the Na coordinated edge. 0.03 A be tween these ave rage values may account for Similar e ffects would be e xpected in the oth er CO:l part of tr e differe nce in angles of the C 0 3 groups be group, whe re 0(1 , 2) and 0(1 , 21) are coordinated to cause 0 (3) and 0 (4) are bonded more s trongly to Ca Ca and 0 (2 . 21) is coordinated to Na. He re the angles, and the 0(3), C(2), 0 (4) angle would the n be expected 119.6(1) for th e Ca coordinated edges and 120.9(2) for to be decreased more tha n the 0 (1), C(1), 0(2) angle. the Na coordinated edge are in the right directions In th e absence of hydrogen bo nding, the oxygens co from 120°, bu t are more nearly equal, which s uggests ordinated mos t strongly to cati ons may be expected to that the effect is more complex than this simple rea have the longest C - 0 bonds. This is qualitatively the soning. The ave rage of the di stances Ca 0 (3) and case. Similar e ffects have been observed in NaZC03 ' Ca ... 0 (4) is 2.493 A; that of th e Ca . . . 0(1) and H 20 [11] , CaNa2(C03k5H20 and CaNa2(CO:1h-2H20 FIGU RE 4. Th e environments a/the CO,,'gro ups in Ca,Na,(CO,,}.,. The primes refer ro atoms in table 5. 133 _[9] and in the P04 groups in Ca7M~J(Ca" Mg)z(P04 )12 the atomic optical anisotropy on the e nvironme nt [1 3]. In the C(I) C03 group in Ca2Na2(C03h, the bond s hould be in corporated. distance C(I) - 0(2) and the symmetri cally equivale nt di stance C(I) - 0(21) are sli ghtly longer thC\n C(I) - 0(1). TABLE 6. R efractive indices for shortite 0(2) is coordinated to two Ca ions and two Na ions; 0(1) is coordinated to one Ca ion and one Na ion. In the Wick- Orie nta- C(2) C03 group, C(2) - 0 (3) is appreciably longer than Observed man 's Here lion the two equivalent di sta nces C(2)-0(4) and C(2)- mod e l 0(41). 0(3) is coordinated to two Ca ions and two Na ions; 0 (4) is coordinated to two Ca ions and one Na ion. The diffe rences in the coordinations of 0 (3) and 1.531 1_ 515 1.502 c 1. 555 1.545 1.541 a 0(4) here do not appear large enough to explain the 1. 570 1.555 ] .554 Ii 0.035 A differepce in C - 0 bond lengths. The dif ference, 0.020 A, in th e bond lengths C(I)-0(2) and C(2)-0(3), may be partly explained by th e fact that while the C(I) C03 group has two longer bonds, the C(2) C03 group has only one, which may the refore be expected to have approximately twi ce the extension J. S. Bowen collec ted the diffractometer data; P. B. due to the cati on field that the C(l) - 0 (2) bonds have. Kingsbury used the ORTEP program of C. K. Johnson , The C(I) atom in the C(l) C03 group is 0.012(3) A Oak Ridge National Laboratory, to draw the fi gures. out of the plane defin ed by the 0(1), 0(2), and 0 (21) This investi gation was s upported in part by research atoms. This may be a result of perturbation of the Sp2 grant DE- 00572 to th e American De ntal Association hybridization of the oxygen atoms by neighboring cat from the National Institute of Dental Research and is ions. The C(2) C03 group is planar by symmetry. part of the dental research program conducted by the National Bureau of S tanda rds, in coo peration with the 4. Discussion American Dental Association; the United States Army Medi cal Research and De velopment Command; the De nta) Sciences Division of the School of Aerospace The positions given by Wickman, (0.0, 0.226, 0.743) Medicine, USAF; th e Nati ona) Ins titute of Dental for C(I), (0.0, 0. 325, 0.850) for 0 (1), and (0.230, 0.177, Research; and the Veterans Administration. 0.690) for 0(2), which are 0.57, 1.98, and 0. 31 A, respec tively, from the positions given here, show that in hi s structure the C(1)03 group has been reflected along c S. References through th e plane z = 0.75, so that 00) then juts out into the void instead of bein g on the void surface. The [1) Di c kens, B.. an d Brown, W_ E .• The crysta l struc ture of inte ratomic distances are reasonable in Wickman's CaCO, . 6H, 0 at - - 120 °C, Inorg. Che m. 9 ,480-486 (1970). structure and the 0 ... 0 re pulsions are therefore [2) Di c ke ns _ B. , and Bowe n. J. So. Refin e ment of th e c rystal struc approximately the same in the two models. In the ture of aragonite (CaCO,,), .1- Res _ Nat. Bur. S ta nd_ (U_S.) structure re ported here, however , 0(1) is able to form (in press)_ stronger bonds to the two Ca ions above and below it (3) Fahey, 1. .I .. S hortite. a new carbonate of sodium and calcium , along a, and to Na(I ) in the same planr parallel to Am. Min _ 24, 514- 518 (1939)_ (100); this is probably the factor governing the orienta tion of th e CO:) group. The calculation of refractive r4) Wic km a n. F. E. . The crys tal structure of s hortite. Ca, Na,(CO"h. indices in the way originally given by Bragg [14] Arki v for Mineral. Geol. 1 ,95- 101 (194.9). assumes that only oxyge n atoms have optical anisotropy IS) Finger. L. W .• Determination of cati on di stribution by least and ignores all interatomi c interactions. Thus, Wick squares refin ement of sin gle·crystal X- ray data, Carnegie man, following this procedure, was able to obtain Instit ute of Washington Year Book 67, 216- 217 (1969). qualitative agreement between observed and calcu [6) Cromer. D. T.. and Mann. J. B., X·ray sca llerin~ factors COIll lated values using a model in which th e orientation of put ed from nume rical Hart ree Fock wave fun cti ons. Acta the C(I) C03 group relative to the (001) plane was C rys\. A24, 32 ]- 324 (1968). ~ 35° instead of - 31 ° 42'. The average orientations of C(I ) C0 groups in the unit cell are about the same for 17) Zachariasen, W. H .. A general th eory of X-ray diffraction in 3 c rys tals. Acta e ryst. 23, 558- 564 (1967). the two models when one takes into account the sym metry operations. This agreement can be seen from 18) Di ckens. B .• and Bowen, J. S .. A refine me nt of th e crystal struc ture of BaCa(C O,,), (barytocalcite) . .I. Res. Nat. Bur. Stand. table 6, which compares the observed indices with the (U.S.) (in press). values calculated for the two models using Bragg's procedure. A much more suitable test of these models, [9) Di c kens, B .• a nd Brown, W. E., The crystal s truetUJ'es of CaNa,(CO,d, . 5H,0. synthe ti c gaylu ssit e. a nd CaNa,(CO,,}, . which would produce better quantitative' agreement 2H,0. synthe ti c pirssonite.lnorg. C hclll . 8 , 2093- 2103 (1969). with the observed values, would require consideration of dipole-dipole coupling terms and optiC'll ani sotropy [10) Dicke ns. B .• and Brown, W. E., The crystal structure of of all atoms, especially Na, rather than just oxygens Ca,(PO~hS i O, (s ili co-carn otite), Tschermaks Mi neral. Lind [15 , 16]. As a further refinement, the dependence of Petrog. M ilt e ilun~en lin press). 134 [11] Di c ke ns, 13. , Ma u C!" , F. A., a nd Brown , W. E. , A re finemellt or 11 4] 13rap:g , W. L. , The refra cti ve indices of calc it e a nd a ra /.( o nit e , the c rys ta l s truc t u re .. I' N a,CO,, · H, O ..1 . Res. N a t. Bur. P roc . R oy. Soc . A 105 . 370- .386 (1924). S ta nd. (U.S.), 74 A . W hys. a nd C hc m. ). 3 1 9- :~2 4 (1970). [1 5[ La wl ess. W. N .. a nd De vri e s . R. c. . O xyp:c n pnl ariza bility a nd point-di po le th eo ry in th e c arbll il a te mi ll e ra I,. .l . Phys. C h e m . [1 2] C hessin . 1-1 .. Ha m ilton. W. C .. a nd Pus t. 13 .. Pos ition a nd t he rmal Solids 25.11] 9- 1 124 ( 1964 ). pa ramc ters of II xyp:pn a tollls in c a lc it ic' . Ac ta C rys t. 18. [1 6] Davis. T. A., a nd Veda m. K .. Va ri a tio n "I' til,· n ' f""eti vl' indic E' s 689-{i93 (i 965) . (If ca lc it e . with pre ssure til 7 Kba r. Ph y,. Stat. S o lid s 2(), [1 3] Di c ke ns . 13. , and 13 ""wn. W. I':., The crysta l s truc ture " I' 285- 290 (1968). Ca, M::",(Ca, VI /.( j, IPO d" . T sc il e nna ks \1in E' ra l. und P t' tr o~. !\Jitt e ilun ~ e n (in pre ss). (Paper 75A2- 656) 135 JOURNAL OF RE SEARCH of th e N at ional Bureau of Standards - A. Ph ysics and Chemistry Vol. 75A, No.2, March- Apri l 1971 Publications of the National Bureau of Standards'" Selected Abstracts Be rger, M. J., Seltze r, S. M., Bl'e m ss t" a hlun ~ a nd pho to n e ut" o n s ral1l e le rs in the S= 1/2, 1= 3/2 ma llifo ld a rc: [:.,. = 2. 109. !!,, = 2.094. f,.o m thick tungste n a n d tanta lu m tat'get s, Ph ),s . R ev. C, 2, [::= 2.346, A~ I =+ IS.7 x 10- 1 em- I. A:;" =+ 27.2X 10- 4 c m I. No. 1, 61 ' - 6.~ ' (A II !!lIsl 1970). A~' = - 87.5 X 10- 1 c m- I. " ';:' =+ 18.8 x 10- 1 ~' Ill I. A~;'-> =+ :Z8.7 X 10 I c m - I.A~-' =- 93.7 X 10- 1 e m- I.p,,. =- 2.S6 X 10 I. P,, =- 2.37 X 10 I. Key wo rd s: Bre msslra hluni(: bre mssl rahl ung effi c ie ncy: Yl onl e 1' ,=+ 4.9:3 X ] 0- 4 c m- I. The magnitudes and re la live s ii( ns of Ih ese Carl o: pholo n neul ron: radi a l io n I ra nsporl: I hic k la ri(cts. pa ra me te rs have been delerm in ed experi menl a ll y whil e II Ie a bsolul e ;; ip:n s hav,' been w ed ic lt'd Ih eorcli call y fmm a model whi c h giv es a Monl e Carl o ca lc ul al io ns have bee n ma d e of el cclron-p holon cas eon"is lt'nl picture "I' Ih !" ordering of Ih .. d" ekcl ron ic s la les. In cades in Ihi c k lungsle nla ri(e ls bo mba rded by e lecl ro ns wilh t' ne rgie" a ddil io n. I he I heorel ical I rcalmcl1l gi ves a sal is faclo ry esl i ma l e o f P. up In 60 .Vle \'. TIlt' foll ow in g information has becn obla incd: I I) Ih e Depa rt ure from tc lragonali t y was taken into accou n t. Tht, ('ova l(' IH'Y bre msstraldung dT-ic ic ncy. (2) Ihe a ngu la r d is lribuliOIl of Ihe c milled para nwl n 0" wh ic h m easurcs Ih (· fraclion of Ih .. hole wave func lion bre msstra hlung inl cnsil y. (3) Ih c s peC lra of Ih c b rc msslra hlung on Ihe e u" is found 10 be 0.71. a nd K. Ihe faelo r givin g ri se 10 c mill cd in va rio us dircc li ons. (4) Ihe Ira ns mi ssion of prima ry a nd iso lropic h yperfin (" "Iruc lure. is fo und 10 1)(' 0.3 1. seconda ry e lectrons Ihrough Ih e largel, (5) e ne rgy depositio n as func lion of Ihc depth in thc la rgel. (6) Ih e diffe re nlia l pholon Irac k· Ensign. T . c., S toko ws ki. S. E .. 5 h at'cd h o les t"appe d b y charge lengl h d istribulion ins idc Ih c largel. a nd (7) Ih e yie ld of ph .. loneu d e fects i n S .,TiO", Ph),s. Rev. Fl , 1, No.6, 1799- 28 10 (Morch 1.5, trans. The paper also in c ludc s va ri ous compa ri sons with ex pcrimenlal 1970). d a ta. K(· y wo rd s : Color ce nl e rs : I~ PH. : hole ('1' 111('1'5: 0Pli cal a bsorpli on: Bloc k. S .. Weir. C. I ~ .. Pil'rma rini. C. J .. 1'0 ly mol'l, his I11 in lJ(' n s hared hol cs: S rTiO". ze n e, n alllha lt.'Il(" a n d a nthl'ac'enp at hi ~ h p l 'eSSlIl'e . Science 169, ,586- ,51l7 IAII!!IISI 7, 1970). Us ill g lilt' lechniques "I' E I' I{ a nd opli cal irra di a lion in conjunc li on wi th opti cal ah sorptio n IllC(lS llrCIll(' llt S. W(' have ~u ill ed lI scful Kcy words: Ani hracenc: Iwnzelle: hi gll· pn·ssure: naphl ha lene: informalion about Ih e na lure of some hole e!" nters in SrTiO". polymorph is m. P rimaril y wc hav(' in vesli p:a led s ingle crysla ls doped with a luminum a l le mperatures ncar 77 K. T wo prin cipal cent e rs have been ex· I li p; h-pr(' sS lI rt' opli('al observati o ns lI sinp: a ll1i c r o~('() p f' with th e plored: I I ) Ih .. AI-O ('enl (' r - a Ii ole " ha red among Ih e oxygens whi c h di amond -a nvi l press ure ce ll have (I ) confi rm ed Iha l Ih('l'e is a Iran"i "urround AI" ' . a nd 12) the ,<.() cenler-a hllie " ll ared in a sim il ar lion ill lI a phlha l(, lI c a nd no Iriple po inl III SOOo± IS °e. 12) "ho\\ n fas hion . b UI mor .. deeply Irapllt'd by a c harge defeci "I' unknown that there i ~ a ('(l ITl'spondill f!; hi ~ h - pr css urc tra ns itioll in a nth nHTIH' orii( in. The A I-O- eenl er ariscs afte r band i(ap irra di a li o n a nd is a nd no tri pl", poi nl 10 5500 ± 15°. (3) s hown Ih al a second revcrsibl e c ha raclerized at 77 K by Ihe fo ll ow in i( [:.valu es a nd hype rfin e eon lii gh-pre"sure form of benze ne ex is ts willi " tri ple poinl Iliquid-II · III ) s lants : [: 11= 2.0 137. P:l = 2 .0124. A II= 8 .3 X 10- 4 cm- I• and Ai. = al 5900 ± ISO a nd approxim ale ly 40 kbar,. an d (4) d e mlln ,l raled lli a l. 7.6 X 10- 4 e m - I. The X-O- cenler is presenl before oplieal irradi a al approx im a tel y 500° for a lllhracene. 5S0° for na phll",le ne a nd lioll . No hyperf-in(' , lrueluJ'(' is observed. bUI IllI' i""lrupic g-value is 600° for b", nzent' III. Ill ese maleri a ls Ira n"form irrever" ibl y to dee p 2.0 130 at a ll lcm lwralU rt'" from 4.:2 10300 K. An 800 n nl absorpti on r e ddi s li ' "ra ng(' cII I"n·d produ CI ,. \I hi ch h ave' nol ye l h ('e ll ba nd ar i ~ ill ~ afle r ba nd :!ap excit at ion has bcl' Il ('o lTclat('d with Ih (" characlerized. AI-O (Tnle r. 430 and 600 11m a bsorplioll IJa nds hav(' been corn·la led with th" a bsC' l1 c(' of I,' e'" in Ih e E PH sp .. ctrum. a nd a SOO nm band Bowen. R. I ... C "vs talli ne d im c tIH, c "ylat(' 1110 n omers,./. Dell l al lias a lso bC(' n obsel'v ed. In a ddilion. Ille ro le of iron in Ihe pholo· Res . 49, No.4, llio- Il I S (./uiy-Au[:lIs l 19 iO). c hro ni c p rocesses of S rTiO" is presenled. I; ina ll y. Ih eoreli ea l work utilizing the molecular orbil a l (J' a nd 7r s la tes in 0" sym me lry has Key words: Dinwlhacryla l('s: Ilwrmosellinp: monon1l'r,: le rn a l'y providc d a firm basis for Ih e s harin p: mode l. The experime nta l [: eutecli c: lIrifi ealion nH' lhod" r",ins fo r cOl1lpo , iles: phtha la le vaJut'!' a ll d Il yperfill(, ('()n~la nt s a rc di s(' u ~~(· d ill lig ht of t hi ~ III nci(' I 1l1()nOIl1 (' r s: h i oll l a t (' ri a l ~, a nd a n ' round tn he ill good a~ r(,(,ITl('nt. C Nlain d imel hacrylalc 11l0nomNS can he pre pared and purificd by I ·~ s till . .\ . .I .. '·: dilor. PJ ' f'{ ' i ~ i()n nl P a ~ lIl't ' lu ('n t a nd ealih.'alion. recrysta lli zati o n. Upon mi xing. Ihe c rysta ls liquify by form in g a Seleetcd N B S 1'""",., on "I, 'e lt'ieit~ " " a dio f"( ' qu e n c~ ' , \ ([1. te rnar y ('ulectic. The colorless oil y liquid is , uil a blc fo r usc in 11111'. SI(llId. I/ ·.S.). S,I('c. 1'111)1 . .1110, / '01.4 , 1.56 l)(Ig('s 1./1111(' l ()iO) c omp() ~ it (' formula! iOIl ~ , 85.,50. Sf) C(lI(llog No. CUIO:.WO/I'. I. Ens ign . T. c. . C ha ng. Te-T se. Kahn. A. II. . Hype " fine a n d I1l1elea.· h:( .y \\'41 rd ..;: 1\ c/lll il laIH'(': a nt f'llna: a ll C'll ualnr: hololllt'le r : ca lorim qllad""I'ole intc"aC'lions in c Ol'pe "-dope d TiO" l'/n's. Nel'. etry: horn : impeda IH'(': int erfe rulllclr),: llle a~ Llri ll g ~ys l (,l1l: pll(l~{,: 188 , No.1, im 70() IDee. III, 1()69). power: radiolllf'try: r (,~O ll allt cavity: vo lt ag-t': WaVer. H·m: wav('~lIid(' j UI1('ti.'Il. Key words: Copper: E:P H: !!.faclors: hypnfine inl e raclion: quad rupole ('ollpling: rllti le: titaniulll dioxidl'. T lii ~ volullle is on(' of a n extended !'-i(' ri ('~ w hi c h hrin !!~ lo!!ellH'r ~ om(' of Ihe previou,1y publis hed pape rs, monographs: ab ~ 1 racls, a nd S in gle c rysla ls of TiO,:Cu'> have been in vesl igaled a l 20 K using bibliop: raphi !", by I\;BS a Ulhors dea lin g wit h Ih e preci"ioll n1('aS llre· I he tcchniqu(' of (' 1l'(' 1r Oil par ama~ll(' t if' resonance. Th e- major me nl of specific physical quantilies and Ih e ealihrati nn III' Ihe re fea lurt's of il l(' EI) H s pecl ra ca n 1)(' a llribuled III di va lenl copper la le d mel ro illgy f'CJ uipmenl. Th" conl,'nls havi' he(, 11 selee ll ·d as (3d") in su bSlil uli li ll a l ITi ") s il (·s . Info rm a lion ha" bcc n gai ned being usefu l to Ih e si a ndards laboralories of Ihe Un il ed S lates in a houl bOlh iSlilopcs III' coppe r a nd a boul Ihe in le raclions whi c h con- Iraeing 10 ;'> RS s la ndards Ih e accurac ies of nwas urel11ent needed fOI I cern Ihi s ion . For Ih e s lIbSl iluli onal si ll' Ihe s pi n Ham ilt o nia n pa- researc h wo rk . faelory producli on. or fi(' ld evalu a linn. 137 Volume 4 cont a i,,, reprint s thrnu ~ h .Jun e 1967 on radiu-freque ncy "I' ph ase - c l, a n~in g colli siun s is also in c luded. The result s are COI11- (' ]{'('( ri ca ] measurem e nt s c overillg th e fol lo win g to pics: Powe r. pared to ('x perime nt a l da ta take n with a He-Ne laser o p e r a tin ~ at a S inusoida l V ()lta ~f' and C urrent , E l ec tr u lll a~ nl'li c I·' ields a nd Ant en wav el e ll ~ th of l.l5 !-till . nas. I{adar and Ba sp band Pul,cs. Noi se, Att e nu ati on and PI, ase. Illlpedance. Hadi" Frequ e ncy .\I ate ri a ls. Qu asi·opti cs a nd Milli· Kl ein . I{ .. A field ('mission s tudy of car'bon monoxide on h.c.p. me te r Wav,· s. and Applicatiun s to .\I easure ment Syste lll s. metals ,'he niulIl and l'utlre niurn, SIIIj(l ce Sci. 20, .'Vo. I , 1- /7 tMa rch 1970). Furculo w. W. H. , T('chnical S tandards Coordinatur, Mosaic-par'que t hanlwood s lat f1oor'in!!, .Val . FI "f'. Sialld. tU.S .), VO/lIl1 lary P rod. K, ·y words: Ca rbon monox id e: d" so rption: fie ld e llli ",ion: monox id e: Si alld. 1,- 70, n fl U f!.1'5 tSel'" 1970), 15 ce ll Is , SD Cala/op. No . rh f" niLlIll. rlitheniulll . surface migration . C n .20/1 :17- 70. TIlf' surLJc{' mi grat ion. work fUll ction inc relllc nts. an d d es orptioll of 1 Key words : Floo ring: ha rd wood flo o rin g: ll1osai c-pa rqupl flo o ring: ca rbun monoxi de on two h. c.p. m et als. rllt.' niulll and ruthenium . wer e ~ Ial Hooring. observed with fi"ld e mi s,ion Il' c hniques. Carbon m'''lOx ide is weakl y bOLind to ruth f'niuITI a nd more strongl y hound to rhenium. Fo r a Thi s \ ' olLllll a r y Pro duc t ~t alld a rd ('ov('rs r (' qllir f' nl( ' ll t~ [or g r a ditl ~. cll mple te mo nolayer. the work fun c ti un in c rement is 1. 3 e V fur m o i ~ tur e (' onl e nt. dilllt' ll :, i()l1 s. c Oll struction. and fini sh ror mosaic ru thenium a nd 0.8 for rh c nium. Surface migration comme ncf"S at a pa rquet hardwood slat fl,,,,rin ~ whi c h is int end ed for use in res i readil y ohservahle rate at ahout 125 K fur rut Ir e nium and shuws de ntial. in stitutional. a nd C' ollllll (' rcial buildings. A method for ma r" bo tlr "ounda ry a nd boundary fr lT characte ri sties. Hl, e nium Ir as a n in ~ a nd lab"lin ~ to indicat e cu m pli ance with th e S tandard is a l,; o ill dpfi 'lt'd s urface mi ~ rati o n tempe rature r e~ i o n beca usp th e desorp provid ed . ,Vranufacturt-' rs' r('coJllme lld a tions 011 orde rilll! d ll(J in s ta l ti u ll pf'(' ccdes and ove rl a ps il. T wo we ll defined billding s ta tes for lation a rc in c ludcd in an appe ndi x. TIIP S ta nd ard doe,; nllt cove r CO on rhe nium are scen. floorinJ,! ~ qu a r es o r block s whic h arc fabricated from con ve ntional tOll gue allu groove t ype ~ trip ~ . Ledbett e r. H. VI.. Heed . H. P .. On the mar'tc n sitc cr'ystallol!r'aphy of F c -Ni alloys, Maler. Sci. fOn t:. 5 , .Vo. 6, .14 1 - . ~491.1I)ne 1970 ). Culd, teill . .J. I .. He nd"·r", ,,,. ~: . IY.. Yakll wit z, II .. Invt'stil!ation of lunar' metal par·tidcs I/'roc. Apol/o I I 1, 111 1111' Scil'lI CI' CO llI, '/1111 - K,>y word s: C r y,; tall o~ r a phi c th cory: iron-nicke l all oy : llIart e ns it e. lI ary 1970 , HOII SIOII , Texlls). (; eochi lll . Cos lll uchilll . Aclll 1, 1')9- 5fl 11 970) For tlr .. lirst tilll e latti ce pa ra melt'r data a lld habit pl a ne meaS Urt>· ment s are a vail a hl e fllr a n allo y syste m wlrll se c r ys t al lo ~ raphic f(' a· Key words: Electron probe mi c .... a nal ys is: luna r sa III pies; lu na r tures (' h a ll ~l' c ontinuo usly w ith c nmp o~ ition. This in form atiun has simulation: lunar tl\{'rnw l Ili ~ t o r y: nH'tp()rit('s: prnbt, mic roan al ysis: been I'rlldu ccd for til(' pl all'-like mart e nsiti c trans fllrm atioll in I"c sca nning el ectron Illi("ro ~c op y . has,' alloys cllnt a inill ~ bet ween 29 and 35 wI. % Ni. This pape r present s a c ritica l examination of the dat a from tIl l' viewJlo inl of the Severa l me talli c parti e l(·s f,,"m lun a r fin e ,; amples 84 a nd 8:;- 17.\11 tlll'or if" "I' IIHrr te nsit e c r y,; t a llo ~ r a ph y . It is foulld tlr at th e c urre nt a nd from breccia salllple 46- ] 8A II't'I'l' ill ves ti ~a t e d by n1< 'all s "f th eories cannot e xpl a in th e va ri ation nf tir e Ir a hit pl a ll e with cllmplls i tlj)tica lmic nISC (lI IY. ",ca nning t'lec trl lll Illi (' nl ~(' t)p y and (,Iectnlll pnlbf' tion witlrout in v okin ~ a va r y in ~.) (1.000 to 1.01 3) . .) hein g an isotropic Illic roanal y", is. These partic les ("n ll ~ i ~ t e d 411' two large globules. m eta l el il atatilln paramete r. In addition to tl, e I, abit plane. ,;e vcral quantities s pread on ~ I a" s y ,; plr e re,. ' plintl'r., and Ill eta l in tir e fo a my pumice· Ir ave bee n ca lculated as a fun c ti on of Cllmpos ition : tl,e volume li" p fr a~ ," e nt s. Tire l a r ~e,; t ~ Iohul e Ir ad a structure con sisting of , ~o chani!t' , the m agnitude of th e lattice invari ant deform a tion. the !-tm Fe- Ni dl'ndrilt', in a n, atri x III' troilitc. A Iri gl, Ni rim lV as found magnitude and directioll of th e sllape CI1<:ln!!e. and th e orientation at th e troilit e- dendrit e int...-face. Thc dendritcs ,; lro wc d typi cal Ni re lation slrip. The e ffect,; of errors in latti ce pa rameter and of thermal ~e~ rl' l!a tion. the co mposition at Ihe out side bt'in:,! about 16 w/o N i ex patJ ~ ion art' c on :-. icif'red. witlr 13 w/o Ni at tir e cent er. Tir e trllilit e contained 0.1 to I. :; W/ II Ni and appea ,'s til he in di ,-,·quilibriulll. Tir e rim clllltain, 29 til 46 .\Iann. W. B. , Garfink(·I. S. B. , Edit ors. Radioactivity calilu'ation w/ o Ni a nd about 0. 3 w/o S. Tir e rilll is a y phase ill tir e I:e-\ i-S 'ys· ,t,,"danls, Nal . /JU l'. Sian d. (U.S.), S pec . P"b! ..H / , flO papes te m and was created by the rejpcti on of Ni from th e troilit e. We were (A "t:"sl 1970) S 1.15, SD Ca la /og No. C n. IO:T! I. abl e to syntlr esize th iS ~ Iobul e : tir e ,;a ml' ,; tru ctur,· was obtained . Fro m thi ~ simulation . the coolin!! rate was determined as 2.50 e/set'. Key words: Alplr a- pa rtic le sta nda rd s; calibrat ion con s istc ncy; co Thi, globulc probahl y was crealt'd by th e impact "I' a chondrit e lin in c idence count i ng; d ecay-scheme effect s: e fTi c iency trac inp:: ga mm a· the moon. ray .:5 t and ard s; int ern ational compariso n s: liquid·scintillation count· A ~ Iobul e separa \( ·d fro lll th e breccia roc k appa re ntl y ,; olidified in ~ : raclionu clide half-li ves: radionuciide stand a rd s. quiekl y and th en "lilli I' d s lll wly. tir e rll c k ac tin ~ as a kind of cru c ibl e. This ~ Iobul e ' ,; metal r c~ i o n s cll ntain 2 w/o ;'\ i. I w/o P. 0.3 w/o Co. Experim e nt al procedures and methods used in nille in te rn a ti onal balance Fe. There are al so eutectic region s cont ai nin g ph n~ phide radi oact ivit y standa"eli za t ion la boratori es are described by e i ~ ht fin e inter ~ ro w tlr s "I' kamacit e. tmilit e a nd ca rbid,·s. This pa rti cle a uthors. The I' 0s,ibilit y of a tt a illi,, ~ ace uracies of tir e order of 0.01 shuws a striking ~i mlil ar it y to ~ ph (-' rHi ds from th e Call yo n Di ablo iron . percent a re di scus,;ed . The desirability of carryin g "ut cO Il , iste ncy The ('v ide nce in dicates th at tlri s ~ IIIhul e wa,; proba bl y created by th e c h('cks of :,ra lllm a· ray ~ t a nd a rd s w ith timc . using a 41TY io niza tion impac t of an iron meteo ri te 0 11 Iht' mooll . chamber is e mplr asized. The va lidit y of rad ioacti vi t y stand a rds is The analys is of the nr etal pa rti c le s Ill a kes it c lear tlr at l)IIth meteoriti c exa min ed. lnt ern ation al co mpa ri son s o r ~a ni ze d by thc Burl'au a nd lun ar FI·- FeS int p r ~r"'v tlr a rc prc,;e nt in the lunar fi nes. T he Int ern a ti ona l des P a id s (' t .\Jeslll·es a rc di scussed. An a n alo~ u e lunar m et al is similar to the m eteoritic Ilw tl'ri al in th at it is stir· Ill ethod IIf liquid-sc intill a ti on cou ntin ~ is dcscribed . Cert ain typc s rounded by s ulfid e: both nw tal con stitue nt ,; arc of conr pa ra bl " s iz,·. of radi oactivit y standa rd s are criticized. The fi elds of int erest of structure and Co ellntpnl. Tir e t wo types II I' Ill at" ri a l can be differ· th e two Canadi a n la hllra tori es are discussed. Detail s of th e work e ntiated hy til(' ,; i ~ nifi ea nt :'-Ii and I' c(l nt e nt III' the tra nsformed in p ro~ress at th c Bori s Kidric In stitut e and Na ti onal Bureau of original meteo ritic mat eria l. Standard s a re present ed. HIIII. II. K.. Tlrc ll'·,. of I!"" lase,'s and its applit'ation to expe "i Milligan. D. E. , Jacox, M. E., Spectr'a of radicals in Phys ical mcnt, I'hys. Rev. A, 2, Va. I, l.H- 1·19 1./11/)' 1970). Che mistr')" 4 , Chailier 5 , 19.3 - 1.1 1 (Aca demic Pre5s I lIc., New York, N. Y., 1970 ). Key wo rd,;: Colli s ions: ~as laser: lin e widtlr ,;: 11IIWl'l' out put : theory: t Linin g curves. Kpy wllrci ,;: Electro ni c s pectrum: Has lr phot olys is: free radi cals: matrix isolati on: llIol eeul a r orbit als: vibrational spectrum. The ~t' mi- c l ass i ca l theor y of ga~ las t'rs has bef' 1l reformulated u sin g rate equations to describ e tire dens it y matrix tinre he l, avill r. Th e Problc ms a ri sin p: in th e d irect slH'c troscopic de tectioll uf free radi ~ oluti o n tu th ese t'q u a ti oll~ . in thl' fo rm of a Fourier ~t'r i l's. is appli· cals a re s urveyed. Appa ratu s used for th e spectroscopi c stud y II I' cabl e to a rbitraril y lri ~ 1r laSt' r int cn,it ies. A ealcul a ti on of tir e " fTe c t fr pp radi cals in th e ~as phase and tra pped in in ert solid mat ri ce,; is 138 d escribe d. The advanta,:e and limit a ti o n s uf fla s h phut(ll ysis a nd uf Key words: Aluminum a ll oy: c orro sion: direc ti o na l effects: g ra in matri x iso lation s t udie s for tl lP produc tion a nd d e tection of free moqlll(l ltlgy: prefe rred o ri{'ntalion ; ~ In 'ss ('{) rrositlll . radicals a rc cons ide red . Exa mples uf ra di c a ls s tudie d b y these te cilniques ar,· ei u·d . a nd d a ta on the s true tun' and .. he mie a l hondin,: S tudies uf the re la ti ve e ffects III' ,:ra in m or phulo ~y a nd pi"eferred uf th .. se s pe .. ie,; d e ri vpd fmm tile obs erved s pec tra are corre lated orientation Oil tllf' direction al slisce ptibilit y to illl (' r ~ra nul a r s lr ('~~ with th e pre dictions of s imple molec ul a r .. rbit a l theory. c orrus inll c rac kin ;!; uf a 7075- '1'65 1 a lulllin u ll1 a ll oy plate h ave h c e n c onduc ll ·d. Ti,e rol e of ,:ra in ll1 o rpholo,:y was found to be of para Re ima nn. C. W .. Sa nt o ro. A., '\li,:lIell. A. D., The ('I'ystal moleeu mou'nl import all c.:e in controlling crack propagatioll. II wa:-; fo und lal' s ll' uetul'e of h exalJ), I'azole l1ickel(ll) nill'ale , Ni(C"R,NJG that a ~ l o\V rate of pr opa~a ti t)n a lo ll :,! gra in boundaries para ll e l 10 (NO"),, Arll1 C,·)'sl. B26, Part S, 5:2 I- S:26 IMay 1970). the a pplied s trt'ss. a nd the fact tha t t ill' inter,:n.n u l"" Ruff, A. W .. Jr.. Measul'cmcl1t of s ta ck in~ fault eIlCI'~ )' f"om K ey wo rds: A lk a ne s : 11 eals : n -hexatricoilianc; II -p ri s ta ll c: II -telra tlislocation inlel'actio n s, M el . Trail .,. 1, No.9, :!391 - :N I.J (Seill . ('1 ):-,a l1 (,; lI -t{' lra n4)llaconl a ll f'_ va pt1ri za tioll . 1970) . Th" ra tl'S II f Ill o l"clll ar vapori zati o n of fo ur lin ear a lka nes. II -pri, ta n e Key word s : Di slocations : dis locati"n nudes: dis loc a ti " n ribbons ; Ie,,). n · t,·tracosa Il C (e,,). lI · hl'xa triconla ne IG,,;), a nd II -te tra no nacon faulted di s locati on dipo ll'';: s t ae kin ~ fa ult ene r ~y: s t ac kin ~ fault tane (C,,) was m easure d . By bo th is ot herma l a nd Il o ni s o the rma l te t ra he dra . m e thuds, the kine ti cs 411' the vaporiza ti o n process s howed ess(' nti a ll y zero order lJ e lr avio r as a vaporization process propo rti onal to Ih(' su r The tlr e"ril's a nd m e thods app li e d to tir e det e rmina tion of ti ll' s tack face a rea s lllluid . The Arrhe nius ,d o pe plus ::l NT/2 was c'''llpa red to in ,: fau lt e ner ~y (Y) u sing Il'c hniques of dirlTt obse rv a tion of dis loca he a ts "I' vapurizatiun of o the r II -alka nes in til e lit e ra ture . Th e u ld a nd tion co nfi ~ ur a ti u n s a re revicwed . The fo ur princ ipa l methods . new d ata s how tlr a t t he Ileal or va porizal iun i s propo rl inll ed 10 I h(' utili z in~ dis lo cati o n nodes, multiple ribbons, s t ack in ~ fau lt te tra two· thirds power of the n umbe r. II. of ca rbon a tums in th e s pecie s he dra. a nd fau lt ed dipo les. a rc di scussed in det a il. Diffe re n t the,,' a nd Ilut to till' firs t power. The m ajurit y of til e known h eats ofva pori re ti ca l treatments arc compared wh e rever pussibl l" Experim e nt a l zati o ll were we ll fitted IJY the e quati on , procedures and qlla nl it al i ve m eas urement m el ho ds are rev iewed. De tai le d examples of till' a pplicati o n of eac h mcthod a re ~ i v('n. F"r MI ,. = 1:,.4:, 11'1"-0.08075 T + 12.22. KJ / lllol Y/ IJ-b in the r a n~, · of 2 x 10- 4 to 5 x 10- :1 (IJ- the s ht'ar modu lus. Ii the Burg:e rs vecl(,r). IllCClsu n ' /Il c nl s (I ll dislocati on nodes or multiple TIll' te tranunilcunta ne va po ri zed withou t d e tection o f h ydrocarbon rihbons in favora hl e casl's s houlel pe rm it d e te rmina ti o n s o f the dccompos iti on product s b y mass s pcctra l m o nit ori n ~. The rcsilit s s tack in ,: fa ult e n er~y to a prccis iun of 5 percent. Fu r l a r ~e r valu es of s u,:,:ests a mu c h hi ;.dlt'r limit to t he s ize of s pecies ca pable of molecu Y/ IJ-b (up to 12 X [0- "), nll'asurl' Ulents ean be made on tl'lra lr eelra lar val" " 'izati u n witho ut d ecom pos ition , tha n p reviuus ly assumed. or faulted d ipo les w ith le ss precis io n . I . a r ~e r val ues of the s tack ill ': fa ult e lwr~ y r e quire hi ,:h re,olutioll s tud ies of dislocatio ns: these W est. E. D., C hurn ey. K. I.., Theor), of isopel'ilJol ealo";nwll·)' techniques a re not yet well esta blis he d. Possibl e s o urces of sys· 1'01' lascl' POWCI' anti c nel '~)' m c a s lll·cl1wnl.s, ./ . Allpl. I'hys. 41 , tematie bias a rt' discu ssed. Two s ignificant theore ti cal proble ms No.6 , :!70S- 171:! 1/\llay 1970). remaill c "n cl'1' nin ~ the treatme nt of the di s location core and the u se of allisotropic c lasti c ity. It is of prime impo rtance tv c h a racte ri ze Key words: Calorime try: laser calorim e try; lasers; the rmadynamics. as care fully as possible the m a te ri a ls s ludie d if accurate results are d esire d. I.ase r pOW l'r and e ll e rgy m e a s ure m e nt s a re c o mmo nl y m ade in ca lo rimete rs o pe ra ting ill a e onstanl-t ~ lllp e r a tllr {' e nvi ro nmt'nt. These Simson, B. C. , Mandel, .1. , Bre nne r, F. C ., H esea l'ch fOI' a unifOl'1ll calorime te rs a re a na lyzed in tnllls o f the firs t law of t he rnHld yn a mics quality ~I ' adin:! ~ys l l'nl fOl' lil'es. Ill. Br·eakin:.r c neq.!;Y, a nd the boundary valu e problem d escribin,: heat fl uw in til e ca lo' RuiJiJ er Che m. Tech. 43 , No. :2 , .JS6-.~69 IMa.rch 1970). rim ete r . Thi ~ tlr e ory of the m e a s ure me nt s ll g:~es t d es i ~ 1l features or Ih(' c alorime te r. s ources of e rro r to be avuid e d in d es ign a nd OPCI'C..I Key word s: Bia ~ pl y; brea k ill).!; energy; passenge r car; radia l: tire ti o n , and test" to delllons tra te experimenta ll y the adequacy of the stre ngth: tires: winll' r. d esig n. '1'1,, · a n a lysis s hows how time -t e mpe ra ture data can 1Jl' us ed tll a ll ow for til e kmpera tur" ~ r a di e nt on the calori mete r il nd the A It's t procedure. d" s i";lll'd to c lassify tin's accord in .,; to tll e ir heat ('xc lr i:lllgt' due to tran sie nt s in tir e te mperatu re. a verage br ca kill ~ e ll l' r ~y has 1H.'e1l appli('d to a ~alll pl e of pU SS l'llgcr car tires. D a ta are repo rte d on 127 differc nl tires 0.1' a ll ~ r a d es a nd types ovcr a ra n ge o f s izes. Other NBS Publications A sca lin ~ syste m is devis l, d and app li e d to the d a ta. It is found tha t the s ys tcm lead s to conclus ions s il1lil a r to those de ri ved from the ori gina l data. J. Hes. Nat. BUI·. S land. (U.S.), 74C (En~. and JI1 SIl·.), Nos. 3&4 (Jllly -Det·. 1970), SO Ca lalo~ No. CI3.22/, e(·.C:74/ U~ ia",; ky . C. \1. . S ko lni c k . I" P. , S ti e fe l, S . W ., Direc tional clreels 3&4. $ 1.25. in the s tress cOI... osion c ' I' ac kin~ of an aluminum alloy, Cor T echniques for c Olllparin~ fo ur-te rmina l-pa ir a dmi tta nce s ta nda rds. rosion 25 , No.2, 77- 86 (V ebruary 1969). R. D. C utkos ky. 139 Some applications for series impedance elements in radio freque ncy Phucas, C. B. , Technical Standards Coordinator. Glass stopcocks immittance measure me nts. L. E. Huntley. with polytetraAuoroethylene (PTFE) plugs , Nat. Bur. Stand. A pul se heating method for the measure me nt of m e ltin ~ point of elec· (U.S.), Voluntary Prod. Stand. 28- 70, 10 pages (Sept. 1970) 25 trical conduc tors (thin wires) above 2000 K. A. Cezairliyan. cents, SO Catalog No. CI3.20/2 :28-70. A tim e·shared co mputer system for diffractometer control. H. A. Reed, R. P., Arp., V. D., Techniques for measuring stress, strain Alperin and E. Prince. and resistivity at 4K for very soft mate rials. Cryoge ni cs Letter to Tensile deformation of vapor·deposited copper reinforced with Editor, 9, No.5. 362-364 (Octobe r 1969). tungste n wires. W. D. J enkins, W. A. Willard, and D. A. Harne. Roder, H. M., Diller, D. K , Thermal conductivity of gaseous and "Connector·pair" techniques for the accurate measure ment of two· liquid hydrogen, J. C hern. Phys . 52, No . 11,5928- 5949 (June 1, terminal low·value capacitances. A. Millea. 1970). The use of dew·point te mperature in humidity calcu lati ons. A. Wood. Searles, S. K., Sieck, L. W. , Ausloos, P ., Reactions of -:: ,H,i. For· Bolovac application for HF and mi crowave power measureme nt a nd mation of the (C,H6 }l ion , J. Chern. Phys. 53, No.2, 849- 850 standardization. M. C. Selb y. (July 15, 1970). Publications of th e Nati onal Bureau of Standards. Searles, S. K. , Sieck, L. W., Hi gh pressure photoionization mass I nd ex to volume 74C, J anuary- Dece mber 1970. spectrometry, Ill. Reactions of N O + (X'~ + ) with CI'C, hydrocar· bons at thermal kineti c energi es, J . Chem. Phys. 53, No.2, 794-797 (July 15, 1970). Borie, K, Radiative corrections to back scattering, Phys. Rev. C, Sharp, E. J., Weber, M. ]., Cleek, G., Energy transfer and fluor· 2, No.2, 770-771 (August 1970). escence que nching in Eu· and Nd·doped sili cate glasses. J. Appl. Candela, G. A. , Spin relaxation process of c hromium ion in potas· Phys. 41, No.1, 364-369 (jan. 1970). sium alum., J. C he m. Phys. 52, No.7, 3754-3757 (April 1, 1970). Shinyayev, A. Ya. , Butrymowi cz, D. 8., Interdiffusion in and th e Evans, W., Garvin, D., The evaluator versus the chemi cal lite rature, phase diagram for vanadium·rich alloys of the V·AI syste m at J . Chem. Doc. 10, No.3, 147- 150 (1970). pressures 0 to 47 kbar, Mel. Trans. I, No.7, 1905-1907 (july Feldman, A., Brower, W. S., Jr., Horowitz, D., Optical activity and 1970). Faraday rotation in bi smuth oxide compounds, App!. Phys. Let· Stein , P. G. , Lipkin, L. K, Shapiro, H. M. , Spectre II: General· te rs 16, No. 5,201- 202 (M arc h 1, 1970). purpose mi croscope input for a computer , Science 166, 328-333 Feldman, A., Kahn, A. H. , Landau di amagne tism from th e coherent (Oct. 17, 1969). states of an electron in a uniform magneti c fi eld , Phys. Rev. B, Straty, G. c., Prydz, R. , The vapor pressure of liquid fluorin e 1, No. 12 ,4584-4589 (June 15, 1970). (Proc. 1969 Cryogenic Engineering Conf., June 16- 18, 1969, Frederikse, H. P. R , Comments on electronic trans port in transition Univ. of California, Los Angeles, Calif.), Chapter in Advances in metal oxides, J . Res. Develop. 14, No.3, 295- 300 (May 1970). Cryogenic Engineering 15, Paper No. B- 1, 36-41 (plenum Press, Hosler, W. R. , Low resistance contacts on semi conducting oxides, Inc., New York, N.Y. , 1970). Solid·State Electron. 13, 517-519 (1970). Sugar, J ., Spectrum of doubly ionized thulium ('I'm Ill), J. Opt. Howett, G. L., Achromatic·point predic tion , J. Opt. Soc. Am. 60, Soc. Am. 69, No.4, 454-466 (Apr. 1970). No.7, 951- 958 (july 1970). Sugar, J ., Configuration 4f"'5d of doubly ionized ytt erbium, J. Opt. Hubbell , J. H., X·ray absorption 75 years later, Phys. Bull. No. 21, Soc. Am. 60, No.4, 571- 572 (Apr. 1970). 353-357 (1970). Swartzendruber, L. J. , Bennett, L. H. , Clu stering, cold work, and Hummer, D. G., Mihalas, D., Model atmos pheres for the central the Mi'ssbauer effect doublet structure in Cu·Ni·Fe alloys, Physics stars of planetary nebulae, Monthly Notices Roy. Astron. Soc. Letters 3IA, No. 10,581- 582 (May 18, 1970). 147, No.4, 339-354 (1970). Wilson, W. K., Fletcher, D. G. , P aper researc h at the National Hust, J. G., Thermal anchoring of wires in cryogeni c apparatus, Bureau of Standards, Indiall Pulp Paper 24, No.7, 325-329 Rev. Sci. Instr. 41, No. 5,622--624 (May 1970). (J an. 1970). Johnson, W. T. K. , Chertok, B. T ., Di ck, C. E., Study of nuclear Wolcott, N. M. , Falge, R. L. , Jr., Cluster s pecifi c heat in Cuo .• NioA states of several odd·A nu clei 68 ,,:; Z ,,:; 79 through electromagneti c alloy, J. Low Te mp. Phys. 2, No. 314,329-331 (1970). excitation from 2.3 to 3.6 MeV, Phys. Rev. Letters 25, No.9, Younglove, B. A., Measurements of the dielectric constant of sat· 599--602 (August 31, 1970). urated liquid oxygen (Proc. 1969 Cryogenic Engin eering Conf., Kasen, M. 8., The effect of grain boundaries on the recovery of June 16--1 8, 1969, Univ. of California, Lo s Angeles, Calif.), Chap· electrical prope rti es during annealing, Scripta Met. 4, 575- 580 te l' in Advances in Cryogenic Engineering 15, Paper No. C- 3, (1970). 70-75 (Plenum Press, Inc., New York, N. Y., 1970). Mann, D. 8., Roder, H. M., Liquefi ed natural gas as a cryogeni c fluid - instrumentation and properties (Proc. Trans mi ssion Conf. * Publications with prices and S D Catalog numbers indicated may American Gas Association Operation Section, New Orleans, La., be purchased directly from the Superintendent of Documents, U.S. May 26-27, 1969), pp. T- 98- T- I06 (American Gas Association, Government Printing Office , Washington, D.C. 20402 (f'oreign: Arlington, Va., 1970). onejourth additional). NBS nonperiodical series are also available Meijer, P . H. E., O'Keeffe, D. ]., Low·temperature behavior of a from the National Technical Inf'o rm.ation Service (NTIS) Spring· pure dipole·dipole system, Phys. Rev. B, 1, No.9, 3786-3800 field, Va. 22 151 lform.erly the Clearinghouse f'or Federal Scientific (May 1, 1970). and Technical Inform.ation). Reprints from outside journals and Nimeroff, L, Deuteranopic conve rgence point, J. Opt. Soc. Am. the NBS Journal of Research may often be obtained directly from 60, No.7, 966-969 (July 1970). the authors. u.s. GOVERNMENT PRINTING OFFICE, OL 197 1- 413- 992 140