MODEL CREATION AND ELECTRONIC STRUCTURE CALCULATION OF AMORPHOUS HYDROGENATED BORON CARBIDE A THESIS IN Physics Presented to the F c!"ty o# the Uni$ersity o# Misso!ri%& ns s City in p rti " f!"#i""(ent o# the re)!ire(ents for the de*ree MASTER OF SCIENCE +y MOHAMMED BELHAD, LARBI B. S., Uni$ersity o# H ssi+ Ben%Bo! "i Ch"e#, A"*eri , 2010 M. S., Uni$ersity o# H ssi+ Ben%Bo! "i Ch"e#, A"*eri , 201/ & ns s City, Misso!ri /012 2015 MO HAMMED BELHADJ LARBI ALL RIGHTS RESERVED MODEL CREATION AND ELECTRONIC STRUCTURE CALCULATION OF AMORPHOUS HYDROGENATED BORON CARBIDE Moh ((ed Be"h dj L r+i, C ndid te for the M ster o# Science De*ree Uni$ersity o# Misso!ri%& ns s City, 2012 ABSTRACT Boron%rich so"ids re o# *re t interest #or ( ny ''"ic tions, ' rtic!" r"y. (or'ho!s hydro*en ted +oron c r+ide 5 %BC6H7 thin #i"(s re "e din* c ndid te #or n!(ero!s ''"ic tions s!ch s6 heterostr!ct!re ( teri "s, ne!tron detectors, nd 'hoto$o"t ic ener*y con$ersion. Des'ite this i('ortance, the "oc " str!ct!r " 'roperties o# these ( teri "s re not 8e""%9no8n, nd $ery #e8 theoretic " st!dies #or this # (i"y o# disordered so"ids e:ist in the "iter t!re. In order to opti(i;e this ( teri " #or its 'otenti " ''"ic tions the str!ct!re 'roperty re" tionshi's need to +e disco$ered. <e !se hy+rid (ethod in this ende $or=8hich is to the +est o# o!r 9no8"ed*e the #irst in the "iter t!re= to (ode" nd c "c!" te the e"ectronic str!ct!re o# (or'ho!s hydro*en ted +oron c r+ide 5 %BC6H7. A co(+in tion o# c" ssic " (o"ec!" r dyn (ics !sin* the L r*e%sc "e Ato(ic>Mo"ec!" r M ssi$e"y P r ""e" Si(!" tor 5LAMMPS7 nd + initio )! nt!( (ech nic " si(!" tions !sin* the 3ienn + initio si(!" tion ' c9 *e 53ASP7 h $e +een cond!cted to cre te *eo(etry opti(i;ed (ode"s th t consist o# disordered hydro*en ted t8e"$e%$erte: +oron c r+ide icos hedr , 8ith hydro*en ted c r+on cross%"in9ers. Then, the density #!nction " theory 5DFT) + sed ortho*on "i;ed "ine r co(+in tion o# to(ic or+it "s 5OLCAO7 (ethod 8 s !sed to c "c!" te the tot " nd ' rti " density o# st tes iii 5TDOS, PDOS7, the co('"e: die"ectric #!nction ?. nd the r di " ' ir distri+!tion #!nction 5RPDF7. The RPDF d t st nd s 'redictions th t ( y +e co(' red 8ith #!t!re e:'eri(ent " e"ectron or ne!tron di##r ction d t . The e"ectronic str!ct!re si(!" tions 8ere not +"e to de(onstr te + nd * ' o# the s (e n t!re s th t seen in 'rior e:'eri(ent " 8or9, *ener " trend o# the co('osition%'roperties re" tionshi' 8 s est +"ished. The content o# hydro*en nd boron 8 s #o!nd to +e direct"y 'roportion " to the decre se in the n!(+er o# $ i" +"e st tes ne r the #er(i ener*y, nd in$erse"y 'roportion " to the die"ectric const nt, 8hich is e:'" ined +y the decre se in net8or9 connecti$ity. The !se o# n ide "i;ed str!ct!re #or the icos hedr 5de#ects e:ist in re "ity7, nd the !se o# the "oc " density ''ro:i( tion #or the e:ch n*e%corre" tion #!nction "=8hich tends to !nderesti( te the + nd* '= re considered the ( in re sons #or the in +i"ity o# )! ntit ti$e"y identi#yin* b nd g ' v "!es th t m tch the e:'eri(ent. i$ APPRO3AL PAGE The # c!"ty "isted +e"o8, ''ointed +y the De n o# the Co""e*e o# Arts nd Sciences h $e e: (ined thesis tit"ed @Mode" Cre tion nd E"ectronic Str!ct!re C "c!" tion o# A(or'ho!s Hydro*en ted Boron C r+ideA 'resented +y Moh ((ed Be"h dj L r+i, c ndid te #or the M ster o# Science de*ree. and certi#y th t in their opinion it is worthy o# cce't nce- Supervisory Committee P !" R!"is, Ph.D., Co((ittee Ch ir UM&C De' rt(ent o# Physics and Astrono(y D %Min* Bh!, Ph.D- UM&C De' rt(ent o# Physics and Astrono(y Eli; +eth Stodd rd, Ph.D. UM&C De' rt(ent o# Physics and Astrono(y $ TABLE OF CONTENTS ABSTRACT ------------------------------------------............................................................................. iii LIST OF ILLUSTRATIONS -----------------------------.............................................................. $iii LIST OF TABLES ............................................................................................................. i: AC&NO<LEDGEMENTS ----------------------------------.............................................................. : DEDICATION ----------------------------------------........................................................................... :i CHAPTER 1 -----------------------------------------.............................................................................. 1 INTRODUCTION --------------------------------------........................................................................ 1 Co('!t tion " Conte:t -----------------------------.................................................. 1 M teri "s Conte:t ---------------------------------....................................................... 2 B c9*ro!nd ................................................................................................. C Moti$ tion ................................................................................................. 11 O!t"ine ...................................................................................................... 1D CHAPTER 2 -----------------------------------------............................................................................ 1E METHODS -------------------------------------------............................................................................ 1E Mo"ec!" r Dyn (ics --------------------------------................................................. 1E Co('!t tion " P c9 *es O$er$ie8 -------------------....................................... 1F L r*e%sc "e Ato(ic>Mo"ec!" r M ssi$e"y P r ""e" Si(!" tor (LAMMPS7 .................................................................................................................. /0 3ienn ab initio si(!" tion p c9 *e (3ASP7 ........................................... /G The Ortho*on "i;ed Line r Co(+in tion o# Ato(ic Or+it "s (OLCAO7 (ethod ...................................................................................................... /C CHAPTER 3 -----------------------------------------............................................................................ D1 SYSTEMS AND RESULTS--------------------------------............................................................. D1 Mode" Syste(s .......................................................................................... D1 Electronic Str!ct!re O$er$ie8 ---------------------............................................. DC Res!"ts ....................................................................................................... DH CHAPTER 4 -----------------------------------------............................................................................ 21 DISCUSSION AND ANALYSIS----------------------------......................................................... 21 CHAPTER 5 -----------------------------------------............................................................................ 2C CONCLUSIONS AND FUTURE WOR& -----------------------................................................ 2C $i Conc"!sions ............................................................................................... 2C F!t!re Wor9 .............................................................................................. 2F APPENDII ------------------------------------------............................................................................. 2H INPUT FILES ---------------------------------------............................................................................ 2H LAMMPS inp!t fi"e .................................................................................. 2H 3ASP INCAR FILE -----------------------------------.............................................. G/ REFERENCES ................................................................................................................. GD 3ITA ----------------------------------------------................................................................................... C/ $ii LIST OF ILLUSTRATIONS FIGURE PAGE Fi*!re 1. Sche(e o# so(e co('!t tion " methods for condensed m tter physics ............ E Fi*!re 26 Sche( tic o# the BEC cryst " str!ct!re (Rho(+ohedr " unit ce""7- -----................ H Fi*!re 36 a7 Mo"ec!" r str!ct!re o# orthoc r+or ne. b7 The e:'eri(ent ""y proposed str!ct!re o# %BC6H ................................................................................................... 10 Fi*!re 46 Sche(e o# di##erent ste's in the process o# si(!" tion. .................................... 1H Fi*!re 56 Mo"ec!" r str!ct!re o# the initi " mo"ec!"es. ( 7 B10C/H1/J (+7 CHDCHDJ and (c7 CHE. With boron pin9, c r+on b" c9 and hydro*en 8hite- ....................................... /D Fi*!re 66 Sche(e o# di##erent mode" cre tion ste's- ........................................................ /E Fi*!re 76 Str!ct!re o# a s ('"e mode" (d1-C%HDD-CC%B>CE-F7 a#ter the post condens tion 8or9#"o8 (+e#ore VASP re" : tion7. ........................................................................ DE Fi*!re 86 Str!ct!re o# a re" :ed s ('"e mode" (d1-C%H/0%B>CE-F7 ................................. DG Fi*!re 9 %*. The c "c!" ted r di " p ir distri+!tion f!nction (RPDF7 o# %BC6H (d1-C% H1D-1%B>CE-F7 ........................................................................................................... E0 Fi*!re 10 %*. The c "c!" ted TDOS o# a%BC6H -------........................................................ EE Fi*!re 11 %*. The c "c!" ted PDOS o# a%BC6H--------........................................................ EG Fi*!re 1/ %*. The c "c!"