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Coordination Chemistry III: Electronic Spectra
160 Chapter 11 Coordination Chemistry III: Electronic Spectra CHAPTER 11: COORDINATION CHEMISTRY III: ELECTRONIC SPECTRA 11.1 a. p3 There are (6!)/(3!3!) = 20 microstates: MS –3/2 –1/2 1/2 3/2 + – – + – + +2 1 1 0 1 1 0 + – – + – + 1 1 –1 1 1 –1 +1 – – + + – + 1 0 0 1 0 0 + – – + + – 1 0 –1 1 0 –1 – – – – + – + – + + + + ML 0 1 0 –1 1 0 –1 1 0 –1 1 0 –1 1– 0– –1+ 1– 0+ –1+ + – – + – + –1 –1 1 –1 –1 1 –1 – – + + – + –1 0 0 –1 0 0 + – – + – + –2 –1 –1 0 –1 –1 0 Terms: L = 0, S = 3/2: 4S (ground state) L = 2, S = 1/2: 2D 2 L = 1, S = 1/2: P 6! 10! b. p1d1 There are 60 microstates: 1!5! 1!9! M S –1 0 1 – – – + + – + + 3 1 2 1 2 , 1 2 1 2 – – + – – + + + 1 1 1 1 , 1 1 1 1 2 + + 0– 2– 0– 2+, 0+ 2– 0 2 1– 0– 1+ 0–, 0+ 1– 1+ 0+ + + 1 0– 1– 1– 0+, 0– 1+ 0 1 + + –1– 2– –1– 2+, –1+ 2– –1 2 – – + – – + + + 1 –1 1 –1 , 1 –1 1 –1 – – – + + – + + ML 0 0 0 0 0 , 0 0 0 0 + + –1– 1– –1+ 1–, –1– 1+ –1 1 – – + – + – + + –1 0 –1 0 , 0 –1 –1 0 – – – + – + + + –1 0 –1 –1 0 , 0 –1 0 –1 – – – + + – 1+ –2+ 1 –2 1 –2 , 1 –2 –1– –1– –1+ –1–, –1– –1+ –1– –1+ –2 + – – + + + 0– –2– 0 –2 , 0 –2 0 –2 –3 –1– –2– –1– –2+, –1+ –2– –1+ –2+ Terms: L = 3, S = 1 3F (ground state) L = 2, S = 0 1D L = 3, S = 0 1F L = 1, S = 1 3P 3 1 L = 2, S = 1 D L = 1, S = 0 P The two electrons have quantum numbers that are independent of each other, because the electrons are in different orbitals. -
Review Sheet on Determining Term Symbols
Review Sheet on Determining Term Symbols Term symbols for electronic configurations are useful not only to the spectroscopist but also to the inorganic chemist interested in understanding electronic and magnetic properties of molecules. We will concentrate on the method of Douglas and McDaniel (p. 26ff); however, you may find other treatments equal or superior to the D & M method. Term symbols are a shorthand method used to describe the energy, angular momentum, and spin multiplicity of an atom in any particular state. The general form is a given as Tj where T is a capital letter corresponding to the value of L (the angular momentum quantum number) and may be assigned as S, P, D, F, G, … for |L| = 0, 1, 2, 3, 4, … respectively. The superscript “a” is called the spin multiplicity and can be evaluated as a = 2S +1 where S is the spin quantum number. The subscript “j” is the numerical value of J, a new quantum number defined as: J = l +S, which corresponds to the total orbital and spin angular momentum of the system. The term symbol 3P is read as triplet – Pee state and indicates that there are two unpaired electrons in a state with maximum orbital angular momentum, L=1. The number of microstates (N) of a system corresponds to the total number of distinct arrangements for “e” number of electrons to be placed in “n” number of possible orbital positions. N = # of microstates = n!/(e!(n-e)!) For a set of p orbitals n = 6 since there are 2 positions in each orbital. -
Comparing the Emission Spectra of U and Th Hollow Cathode Lamps and a New U Line-List
Astronomy & Astrophysics manuscript no. HCL_U_Th_Ull_S2018 c ESO 2018 October 1, 2018 Comparing the emission spectra of U and Th hollow cathode lamps and a new U line-list L. F. Sarmiento1,⋆, A. Reiners1, P. Huke1, F. F. Bauer1, E. W. Guenter2,3, U. Seemann1, and U. Wolter4 1 Institut für Astrophysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany 2 Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany 3 Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Tenerife, Spain 4 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany Received , 22 February 2018; accepted , 5 June 2018 ABSTRACT Context. Thorium hollow cathode lamps (HCLs) are used as frequency calibrators for many high resolution astronomical spectro- graphs, some of which aim for Doppler precision at the 1 m/s level. Aims. We aim to determine the most suitable combination of elements (Th or U, Ar or Ne) for wavelength calibration of astronomical spectrographs, to characterize differences between similar HCLs, and to provide a new U line-list. Methods. We record high resolution spectra of different HCLs using a Fourier transform spectrograph: (i) U-Ne, U-Ar, Th-Ne, and Th-Ar lamps in the spectral range from 500 to 1000 nm and U-Ne and U-Ar from 1000 to 1700 nm; (ii) we systematically compare the number of emission lines and the line intensity ratio for a set of 12 U-Ne HCLs; and (iii) we record a master spectrum of U-Ne to create a new U line-list. Results. Uranium lamps show more lines suitable for calibration than Th lamps from 500 to 1000 nm. -
Mössbauer Spectroscopy 9.1 Recoil Free Resonance Absorption
Chapter 9, page 1 9 Mössbauer Spectroscopy 9.1 Recoil free resonance absorption Robert Wood published in 1905 an article "Resonance Radiation of Sodium Vapor" (see Literature) and reported that if a bulb containing pure sodium vapor was illuminated by light from a sodium flame, the vapor emitted a yellow light which spectroscopic analysis showed to be identical with the exciting light, in other words, the two D lines. Sodium is liquid above 98 °C, boiling point 883 °C, thus a remarkable vapor pressure exists, if sodium is heated by the Fig. 9.1: Wood's apparatus for the Bunsen burner above 200 °C. Wood used the name resonance radiation of the sodium "resonance radiation" for the effect of identical D lines. absorbed radiation and fluorescence radiation. Now we use the term "resonance absorption" instead. Since 1900 γ-rays were known as a highly energetic monochromatic radiation, but the anticipated γ-ray resonance fluorescence failed to occur. Werner Kuhn succeeded in publishing such an experiment that don't work and argued in 1929: "The (third) influence, reducing the absorption, arises from the emission process of the γ-rays. The emitting atom will suffer recoil due to the projection of the γ-ray. The wavelength of the radiation is therefore shifted to the red; the emission line is displaced relative to the absorption line.... It is thus possible that by a large γ-shift, the whole emission line is brought out of the absorption region”. (see Literature, Kuhn) Intensity In the case of γ-radiation the atoms suffer recoil, which is not significant for radiation in the visible range, were the recoil energy is small compared with the linewidth of the h δν1/2 radiation (times h), see Fig. -
XSAMS: XML Schema for Atomic, Molecular and Solid Data
XSAMS: XML Schema for Atomic, Molecular and Solid Data Version 0.1.1 Draft Document, January 14, 2011 This version: http://www-amdis.iaea.org/xsams/docu/v0.1.1.pdf Latest version: http://www-amdis.iaea.org/xsams/docu/ Previous versions: http://www-amdis.iaea.org/xsams/docu/v0.1.pdf Editors: M.L. Dubernet, D. Humbert, Yu. Ralchenko Authors: M.L. Dubernet, D. Humbert, Yu. Ralchenko, E. Roueff, D.R. Schultz, H.-K. Chung, B.J. Braams Contributors: N. Moreau, P. Loboda, S. Gagarin, R.E.H. Clark, M. Doronin, T. Marquart Abstract This document presents a proposal for an XML schema aimed at describing Atomic, Molec- ular and Particle Surface Interaction Data in distributed databases around the world. This general XML schema is a collaborative project between International Atomic Energy Agency (Austria), National Institute of Standards and Technology (USA), Universit´ePierre et Marie Curie (France), Oak Ridge National Laboratory (USA) and Paris Observatory (France). Status of this document It is a draft document and it may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use this document as reference materials or to cite them as other than “work in progress”. Acknowledgements The authors wish to acknowledge all colleagues and institutes, atomic and molecular database experts and physicists who have collaborated through different discussions to the building up of the concepts described in this document. Change Log Version 0.1: June 2009 Version 0.1.1: November 2010 Contents 1 Introduction 11 1.1 Motivation..................................... 11 1.2 Limitations..................................... 12 2 XSAMS structure, types and attributes 13 2.1 Atomic, Molecular and Particle Surface Interaction Data XML Schema Structure 13 2.2 Attributes .................................... -
Atomic Spectroscopy Summary
ATOMIC SPECTROSCOPY SUMMARY TERM SYMBOLS Because the total angular momentum and energy commute, we can use the angular momentum (L) to label the energy states. Note that electron configurations are ambiguous in that we don’t specify which orbital or which spin each electron has. This means that there are a number of different sets of 푚ℓ and 푚푠 that are consistent with a given configuration. Why are there different energies? Because of electron/electron repulsion and spin-orbit coupling, the ways we can fill the orbitals DO NOT NESCESSARILLY have the same energy. (Remember that we talked about how Hund’s rules come from this. How spin up elelctrons interact less with other spin up electrons in the same subshell.) Components of a Term Symbol: 2푆+1 퐿퐽 RULES FOR TERM SYMBOLS Term Symbols are assigned based on two main rules: 1. Unsöld’s Rule: All filled shells/subshells are ignored when calculating L and S. Basically, all of the electrons will have their contributions to spin and orbital angular momentum canceled by other electrons in the same subshell. 2. “holes”: The state of the “hole” (an empty spot in an orbital where an electron could be but isn’t) is the same as the state of an electron. This means that when we look at a p5 we can pretend it is a p1. This is incredibly useful as it means that instead of 5 electrons to tinker with, you can just act like it is 1. CALCULATING L: L is the Total Angular Momentum L= (sum of ℓ values) ….(smallest positive difference of ℓ values) o 2 s electrons (different shells) L=0+0,…,0-0 L=0 o 1 d electron and 1 p electron L=2+1,…,2-1 L=3, 2, 1 S is the Total Spin S is the total spin quantum number of the electrons in an atom. -
Stark Broadening of Spectral Lines in Plasmas
atoms Stark Broadening of Spectral Lines in Plasmas Edited by Eugene Oks Printed Edition of the Special Issue Published in Atoms www.mdpi.com/journal/atoms Stark Broadening of Spectral Lines in Plasmas Stark Broadening of Spectral Lines in Plasmas Special Issue Editor Eugene Oks MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade Special Issue Editor Eugene Oks Auburn University USA Editorial Office MDPI St. Alban-Anlage 66 4052 Basel, Switzerland This is a reprint of articles from the Special Issue published online in the open access journal Atoms (ISSN 2218-2004) in 2018 (available at: https://www.mdpi.com/journal/atoms/special issues/ stark broadening plasmas) For citation purposes, cite each article independently as indicated on the article page online and as indicated below: LastName, A.A.; LastName, B.B.; LastName, C.C. Article Title. Journal Name Year, Article Number, Page Range. ISBN 978-3-03897-455-0 (Pbk) ISBN 978-3-03897-456-7 (PDF) Cover image courtesy of Eugene Oks. c 2018 by the authors. Articles in this book are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book as a whole is distributed by MDPI under the terms and conditions of the Creative Commons license CC BY-NC-ND. Contents About the Special Issue Editor ...................................... vii Preface to ”Stark Broadening of Spectral Lines in Plasmas” ..................... ix Eugene Oks Review of Recent Advances in the Analytical Theory of Stark Broadening of Hydrogenic Spectral Lines in Plasmas: Applications to Laboratory Discharges and Astrophysical Objects Reprinted from: Atoms 2018, 6, 50, doi:10.3390/atoms6030050 ................... -
Quantitative Analysis of Cerium-Gallium Alloys Using a Hand-Held Laser Induced Breakdown Spectroscopy Device
atoms Article Quantitative Analysis of Cerium-Gallium Alloys Using a Hand-Held Laser Induced Breakdown Spectroscopy Device Ashwin P. Rao 1 , Matthew T. Cook 2 , Howard L. Hall 2,3 and Michael B. Shattan 1,* 1 Air Force Institute of Technology, 2950 Hobson Way, WPAFB, OH 45433, USA 2 Institute for Nuclear Security, University of Tennessee, Knoxville, TN 37996, USA 3 Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996, USA * Correspondence: michael.shattan@afit.edu Received: 26 July 2019; Accepted: 20 August 2019; Published: 22 August 2019 Abstract: A hand-held laser-induced breakdown spectroscopy device was used to acquire spectral emission data from laser-induced plasmas created on the surface of cerium-gallium alloy samples with Ga concentrations ranging from 0–3 weight percent. Ionic and neutral emission lines of the two constituent elements were then extracted and used to generate calibration curves relating the emission line intensity ratios to the gallium concentration of the alloy. The Ga I 287.4-nm emission line was determined to be superior for the purposes of Ga detection and concentration determination. A limit of detection below 0.25% was achieved using a multivariate regression model of the Ga I 287.4-nm line ratio versus two separate Ce II emission lines. This LOD is considered a conservative estimation of the technique’s capability given the type of the calibration samples available and the low power (5 mJ per 1-ns pulse) and resolving power (l/Dl = 4000) of this hand-held device. Nonetheless, the utility of the technique is demonstrated via a detailed mapping analysis of the surface Ga distribution of a Ce-Ga sample, which reveals significant heterogeneity resulting from the sample production process. -
Emission Mössbauer Spectroscopy at ISOLDE/CERN
Emission Mössbauer Spectroscopy at ISOLDE/CERN Torben Esmann Mølholt ISOLDE Seminar, 25. Nov. 2015 Outline Experimental setup at ISOLDE Brief on the Mössbauer spectroscopy technique Examples and Results Future/ongoing measurements 2 Acknowledgements The Mössbauer collaboration at ISOLDE/CERN, >30 active members with new members (2014) from China, Russia, Bulgaria, Austria, Spain: Four experiments Existing members New members 2014 (IS-501, IS-576, IS-578, I-161) 3 Emission Mössbauer Spectroscopy at ISOLDE/CERN http://e-ms.web.cern.ch/ GLM (GPS) LA1-2 (HRS) 4 119In RILIS 2014 2015 57Mn 119 RILIS In 15 μSi/h - 57Mn 10 μSi/h - RILIS 5 μSi/h - 0 μSi/h - 5 Mössbauer Experimental setup Implantation chamber Incoming 60 keV beam Sample Faraday cup Be window Mössbauer drive with resonance detector Container: 25 mbar acetone • Intensity (~1×108 atoms/s) • High statistics spectrum (5 – 10 min.) •On-line (short lived) •Collections for Off-line (long lived) 6 •Hours - days Mössbauer Experimental setup Sample holder •Temperature range 90 – 700 K • Measurements at different emission angles • Applied magnetic field (Bext ≤ 0.6 T) 7 Mössbauer Experimental setup Sample holder • Quenching: Implant at high temperature Measure at low temperature (off-line) 8 Mössbauer Experimental setup Resonance detector - G. Weyer, Mössbauer Eff. Meth., 10 (1976) 301 PPAD: Parallel Plate Avalanche Detector - Single line resonance detector. 0.1 cps (~0.1 µCi) – 50k cps (~500 mCi) 9 Mössbauer spectroscopy technique 10 40-60 keV Ion-implantation of Mössbauer Probe Emission -
Glossary of Terms Absorption Line a Dark Line at a Particular Wavelength Superimposed Upon a Bright, Continuous Spectrum
Glossary of terms absorption line A dark line at a particular wavelength superimposed upon a bright, continuous spectrum. Such a spectral line can be formed when electromag- netic radiation, while travelling on its way to an observer, meets a substance; if that substance can absorb energy at that particular wavelength then the observer sees an absorption line. Compare with emission line. accretion disk A disk of gas or dust orbiting a massive object such as a star, a stellar-mass black hole or an active galactic nucleus. An accretion disk plays an important role in the formation of a planetary system around a young star. An accretion disk around a supermassive black hole is thought to be the key mecha- nism powering an active galactic nucleus. active galactic nucleus (agn) A compact region at the center of a galaxy that emits vast amounts of electromagnetic radiation and fast-moving jets of particles; an agn can outshine the rest of the galaxy despite being hardly larger in volume than the Solar System. Various classes of agn exist, including quasars and Seyfert galaxies, but in each case the energy is believed to be generated as matter accretes onto a supermassive black hole. adaptive optics A technique used by large ground-based optical telescopes to remove the blurring affects caused by Earth’s atmosphere. Light from a guide star is used as a calibration source; a complicated system of software and hardware then deforms a small mirror to correct for atmospheric distortions. The mirror shape changes more quickly than the atmosphere itself fluctuates. -
Review of Term Symbols Computation from Multi-Electron Systems for Chemistry Students Jamiu A
S O s Contemporary Chemistry p e s n Acce REVIEW ARTICLE Review of Term Symbols Computation from Multi-Electron Systems for Chemistry Students Jamiu A. Odutola* Department of Physics, Chemistry and Mathematics, Alabama Agricultural and Mechanical University, Normal AL 35762, USA Abstract We have computed the term symbols resulting from the coupling of angular momenta of both spin and orbital from the ground state electron configuration. Configurations of equivalent electrons present challenges and were handled by the group theoretical methods. Terms are the combined values of L and S while the combined values of L, S and J defines the level. Key Words: Terms, Term Symbols, Spectroscopic term symbols, State, Level, Sub-level, Equivalent electrons, Non-equivalent electrons, Orbital angular momentum, Spin angular momentum, Spin-Orbital angular momentum, Russell-Saunders Coupling, LS coupling, j-j coupling and multiplicity. Introduction four quantum numbers (n, l, ml, ms). The first three quantum numbers in the set describes the spatial distribution and the Spectroscopic term symbols are very important in classifying last describes the spin state of the electron. n is the principal the electronic states of atoms and molecules particularly in quantum number and it describes the size or the energy level physical and inorganic chemistry [1-4]. There is a vast amount of the shell (or atom). l is the azimuthal or angular momentum of information on the topic of term symbols and techniques quantum number and it describes the shape of the orbital for obtaining these terms in the literature. Many authors gave or the subshell. m is the magnetic quantum number and it credit to such textbooks as Cotton and Wilkinson [5] as well as l describes the spatial orientation or direction of the orbital. -
Arxiv:Cond-Mat/0404626V1
LA-UR-03-8735 Nuclear Magnetic Resonance Studies of δ-Stabilized Plutonium N. J. Curro Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, NM 87545, [email protected] L. Morales Nuclear Materials and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (Dated: July 14, 2018) Nuclear Magnetic Resonance studies of Ga stabilized δ-Pu reveal detailed information about the local distortions surrounding the Ga impurities as well as provides information about the local spin fluctuations experienced by the Ga nuclei. The Ga NMR spectrum is inhomogeneously broadened by a distribution of local electric field gradients (EFGs), which indicates that the Ga experiences local distortions from cubic symmetry. The Knight shift and spin lattice relaxation rate indicate that the Ga is dominantly coupled to the Fermi surface via core polarization, and is inconsistent with magnetic order or low frequency spin correlations. Introduction tuations of of the electron spin S relax the nuclei so fast that their signal is rendered invisible. On the other hand, The investigavtion of the low temperature properties the hyperfine coupling to the nuclei of the secondary el- of plutonium and its compounds has experienced a re- ement (Al, Ga or In) are typically one to three orders of naissance in recent years, and several important experi- magnitude smaller, so by measuring the secondary nuclei ments have revealed unusual correlated electron behavior one can gain considerable insight into the spin dynamics [1, 2, 3]. The 5f electrons in elemental plutonium are on of the system. the boundary between localized and itinerant behavior, One of the challenges facing band theorists calculating so that slight perturbations in the Pu-Pu spacing can give the electronic structure of δ-Pu is the role of the sec- rise to dramatic changes in the ground state character.