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Nakatsuji H, Nakashima H. Potential curves of the lower nine states of Li2 molecule: Accurate calculations with the free complement theory and the comparisons with the SAC/SAC-CI results. J Chem Phys 2022; 157:094109. [DOI: 10.1063/5.0101315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The free-complement (FC) theory proposed for solving the Schrödinger equation of atoms and molecules highly accurately was applied to the calculations of the potential curves of the lower nine states of the Li2 molecule. The results were compared with the accurate experimental Rydberg-Klein-Rees (RKR) potential curves available. They overlap completely with each other without any shift everywhere for all the states of Li2. At all the calculated points on the seven potential curves ranging between -14.83 ~ -15.00 hartree, the average difference was only 0.0583 kcal/mol and the maximum difference was only +0.165 kcal/mol. For the vertical excitation energies from the ground state curve to the seven excited states, the differences between theory and experiment were 0.000645 eV in average and their maximum difference was -0.00720 eV. The potential properties calculated with the FC theory also agreed well with the experimental values. These results show a high potentiality of the FC theory as a highly predictive quantum chemistry theory. For comparison, as an example of the Hartree-Fock based theory popular in modern quantum chemistry, we adopted the SAC-CI theory using a highly flexible basis set. While the FC theory gave the absolute agreements with experiments, the SAC-CI potential curves compare reasonably well with experiments only after shifting-down of the SAC-CI curves by 5.727 kcal/mol. The differences of the excitation energies between SAC-CI and experiments were 0.00428 eV in average and the maximum difference was +0.10967 eV. The SAC-CI results reported in 1985 were less accurate but still reasonable.
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Affiliation(s)
- Hiroshi Nakatsuji
- Quantum Chemistry Research Institute, Quantum Chemistry Research Institute, Japan
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2
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Sheng X, Li M, Tang KT. An accurate potential model for the a 3Σ u+ state of the lithium dimer. Phys Chem Chem Phys 2022; 24:13325-13334. [PMID: 35608033 DOI: 10.1039/d2cp01490d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An accurate Tang-Toennies (TT) model potential is introduced to describe the interatomic potential of the lithium dimer in the a3Σu+ state. With only one well-known parameter, the ionization energy, the new model potential compares favorably with the experimentally fitted Morse/Long-range (MLR) potential of Dattani and Le Roy [J. Mol. Spectrosc., 2011, 268, 199] and is in excellent agreement with the state-of-the-art ab initio potential of Lesiuk et al. [Phys. Rev. A, 2020, 102, 062806]. With the known dispersion coefficients and the ionization energy, the new potential requires only two experimental parameters, namely the depth of the potential well De and its location Re. The new potential can be extended to the region of zero separation by the united atom limit.
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Affiliation(s)
- Xiaowei Sheng
- Anhui Province Key Laboratory of Optoelectric Materials Science and Technology, Department of Physics, Anhui Normal University, Anhui, Wuhu 241000, China
| | - Mengyuan Li
- Anhui Province Key Laboratory of Optoelectric Materials Science and Technology, Department of Physics, Anhui Normal University, Anhui, Wuhu 241000, China
| | - K T Tang
- Department of Physics, Pacific Lutheran University, Tacoma, Washington, 98447, USA.
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Fanthorpe J, Gao Y, Stewart B. Rotational Energy Transfer in Highly Excited States of Lithium Dimer: Experiment and Modeling. J Phys Chem A 2020; 124:7373-7379. [PMID: 32835478 DOI: 10.1021/acs.jpca.0c04960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report level-resolved rate coefficients for collision-induced rotational energy transfer in the 7Li2*-Ne system, with 7Li2* in the highly electronically excited E(3)1Σg+(vi = 4, ji = 31) and F(4)1Σg+(vi = 10, ji = 31) states. The distributions of rate coefficients are strikingly different from those previously measured for the A(1)1Σu+(vi = 2-24, ji = 30) state of the same molecule, falling off much more rapidly with increasing rotational quantum number change |Δj|. The reason for the difference was explored by means of an inverse Monte Carlo approach employing classical trajectories and a model potential, which was adjusted to give agreement with experiment. The modeling strongly suggests that the E and F state interaction potentials are much more nearly isotropic than that of the A state. The resulting dramatic reduction in rate coefficient, especially for large |Δj|, may be relevant in the relaxation of gases at high temperatures.
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Affiliation(s)
- Jacob Fanthorpe
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Yunxiao Gao
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, United States
| | - Brian Stewart
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, United States
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Chanana G, Batra K, Prasad V. Exploring response of Li2 molecule to external electric field: A DFT and SAC-CI study. COMPUT THEOR CHEM 2019. [DOI: 10.1016/j.comptc.2019.112620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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5
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Yang L, Reimers JR, Kobayashi R, Hush NS. Competition between charge migration and charge transfer induced by nuclear motion following core ionization: Model systems and application to Li 2. J Chem Phys 2019; 151:124108. [PMID: 31575213 DOI: 10.1063/1.5117246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Attosecond and femtosecond spectroscopies present opportunities for the control of chemical reaction dynamics and products, as well as for quantum information processing; we address the somewhat unique situation of core-ionization spectroscopy which, for dimeric chromophores, leads to strong valence charge localization and hence tightly paired potential-energy surfaces of very similar shape. Application is made to the quantum dynamics of core-ionized Li2 +. This system is chosen as Li2 is the simplest stable molecule facilitating both core ionization and valence ionization. First, the quantum dynamics of some model surfaces are considered, with the surprising result that subtle differences in shape between core-ionization paired surfaces can lead to dramatic differences in the interplay between electronic charge migration and charge transfer induced by nuclear motion. Then, equation-of-motion coupled-cluster calculations are applied to determine potential-energy surfaces for 8 core-excited state pairs, calculations believed to be the first of their type for other than the lowest-energy core-ionized molecular pair. While known results for the lowest-energy pair suggest that Li2 + is unsuitable for studying charge migration, higher-energy pairs are predicted to yield results showing competition between charge migration and charge transfer. Central is a focus on the application of Hush's 1975 theory for core-ionized X-ray photoelectron spectroscopy to understand the shapes of the potential-energy surfaces and hence predict key features of charge migration.
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Affiliation(s)
- Likun Yang
- International Centre for Quantum and Molecular Structures and Department of Physics, Shanghai University, Shanghai 200444, China
| | - Jeffrey R Reimers
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Rika Kobayashi
- International Centre for Quantum and Molecular Structures and Department of Physics, Shanghai University, Shanghai 200444, China
| | - Noel S Hush
- School of Molecular Biosciences, The University of Sydney, Sydney, NSW 2006, Australia
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Bhowmick S, Hagebaum-Reignier D, Jeung GH. Potential energy surfaces of the electronic states of Li 2F and Li 2F −. J Chem Phys 2016; 145:034306. [DOI: 10.1063/1.4958829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Somnath Bhowmick
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
| | | | - Gwang-Hi Jeung
- Aix Marseille Univ, CNRS, Centrale Marseille, iSm2, Marseille, France
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Barysz M. Potential Energy Curves in the CASSCF/CASPT2 and FS-MR-CC Methods: The Role of Relativistic Effects. J Chem Theory Comput 2016; 12:1614-26. [PMID: 26914182 DOI: 10.1021/acs.jctc.6b00008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio CASSCF/CASPT2 calculations for the electronic ground and for a wide range of excited states of Li2 and Na2 dimers are presented. The computed spectroscopic parameters agree very well with the experimental data. This indicates that the old CASSCF/CASPT2 method can be as successfully applied to study excited states of molecules as recently developed the multireference Fock-space coulped-cluster method. The role of relativistic effects in the correct description of the potential energy curves has been investigated using as an example the SiAu molecule. The accuracy of the new infinite-order two-component relativistic method has been studied and its advantage over the Douglas-Kroll-Hess method demonstrated.
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Affiliation(s)
- Maria Barysz
- Department of Quantum Chemistry, Faculty of Chemistry, Nicolaus Copernicus University , Gagarina 7, 87-100 Toruń, Poland
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Musiał M, Kucharski SA. First Principle Calculations of the Potential Energy Curves for Electronic States of the Lithium Dimer. J Chem Theory Comput 2014; 10:1200-11. [DOI: 10.1021/ct401076e] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Monika Musiał
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland
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Musiał M, Kowalska-Szojda K, Lyakh DI, Bartlett RJ. Potential energy curves via double electron-attachment calculations: Dissociation of alkali metal dimers. J Chem Phys 2013; 138:194103. [DOI: 10.1063/1.4804164] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rosenberry M, Marhatta R, Stewart B. Comparison of rotationally inelastic rate constants for <mml:math altimg="si3.gif" overflow="scroll" xmlns:xocs="http://www.elsevier.com/xml/xocs/dtd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.elsevier.com/xml/ja/dtd" xmlns:ja="http://www.elsevier.com/xml/ja/dtd" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:tb="http://www.elsevier.com/xml/common/table/dtd" xmlns:sb="http://www.elsevier.com/xml/common/struct-bib/dtd" xmlns:ce="http://www.elsevier.com/xml/common/dtd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:cals="http://www.elsevier.com/xml/common/cals/dtd"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Li</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mspace width="0.35em"/><mml:msup><mml:mrow><mml:mtext>A</mml:mtext></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msup><mml:msubsup><mml:mrow><mml:mi mathvariant="normal">Σ</mml:mi></mml:mrow><mml:mrow><mml:mi>u</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mrow><mml:mi>v</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>5</mml:mn><mml:mtext>,</mml:mtext><mml:msub><mml:mrow><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>30</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math> + Ne measured using pulsed and cw lasers. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2011.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Ahmed EH, Ingram S, Kirova T, Salihoglu O, Huennekens J, Qi J, Guan Y, Lyyra AM. Quantum control of the spin-orbit interaction using the Autler-Townes effect. PHYSICAL REVIEW LETTERS 2011; 107:163601. [PMID: 22107380 DOI: 10.1103/physrevlett.107.163601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Indexed: 05/31/2023]
Abstract
We have demonstrated quantum control of the spin-orbit interaction based on the Autler-Townes (ac-Stark) effect in a molecular system using a cw optical field. We show that the enhancement of the spin-orbit interaction between a pair of weakly interacting singlet-triplet rovibrational levels, G (1)Π(g)(v=12,J=21,f)-1 (3)Σ(g)(-)(v=1,N=21,f), separated by 750 MHz in the lithium dimer, depends on the Rabi frequency (laser power) of the control laser. The increase in the spin-orbit interaction due to the control field is observed as a change in the spin character of the individual components of the perturbed pair.
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Affiliation(s)
- E H Ahmed
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA.
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12
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Stewart BA, Stephens TN, Lawrence BA, McBane GC. Rovibrational Energy Transfer in Ne−Li2(A1Σu+,v=0): Comparison of Experimental Data and Results from Classical and Quantum Calculations. J Phys Chem A 2010; 114:9875-85. [DOI: 10.1021/jp103504a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brian A. Stewart
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, Department of Chemistry, Eastern Illinois University, Charleston, Illinois 61920, and Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401
| | - Troy N. Stephens
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, Department of Chemistry, Eastern Illinois University, Charleston, Illinois 61920, and Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401
| | - Barbara A. Lawrence
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, Department of Chemistry, Eastern Illinois University, Charleston, Illinois 61920, and Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401
| | - George C. McBane
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, Department of Chemistry, Eastern Illinois University, Charleston, Illinois 61920, and Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401
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13
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Salihoglu O, Qi P, Ahmed EH, Kotochigova S, Magnier S, Lyyra AM. Comparison of Autler–Townes splitting based absolute measurements of the L7i2 A Σ1u+−X Σ1g+ electronic transition dipole moment with ab initio theory. J Chem Phys 2008; 129:174301. [DOI: 10.1063/1.3000416] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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14
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15
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Coppage S, Matei P, Stewart B. Absolute level-resolved reactive and inelastic rate constants in Li+Li2*. J Chem Phys 2008; 128:241103. [PMID: 18601310 DOI: 10.1063/1.2951992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have used nuclear parity-changing collisions to obtain absolute level-to-level rate constants for reactive scattering in a triatomic system with identical nuclei. We have determined rate constants for the system (7)Li(2) (*)(A (1)Sigma(u) (+))(v(i)=2,j(i)=19)+(7)Li-->(7)Li+(7)Li(2) (*)(A (1)Sigma(u) (+))(v(f),j(f)), from laser-induced fluorescence spectra of lithium vapor in a heat pipe oven. Parity-preserving collisions yielded measurements of absolute rotationally and vibrationally inelastic rate constants as well. We compare the reactive rate constants with statistical prior distributions and the inelastic results with previously measured results on the Ne+(7)Li(2) (*) system.
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Affiliation(s)
- Steven Coppage
- Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA
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Qi P, Bai J, Ahmed E, Lyyra AM, Kotochigova S, Ross AJ, Effantin C, Zalicki P, Vigué J, Chawla G, Field RW, Whang TJ, Stwalley WC, Knöckel H, Tiemann E, Shang J, Li L, Bergeman T. New spectroscopic data, spin-orbit functions, and global analysis of data on the AΣu+1 and bΠu3 states of Na2. J Chem Phys 2007; 127:044301. [PMID: 17672684 DOI: 10.1063/1.2747595] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The lowest electronically excited states of Na2 are of interest as intermediaries in the excitation of higher states and in the development of methods for producing cold molecules. We have compiled previously obtained spectroscopic data on the A 1Sigmau+ and b 3Piu states of Na2 from about 20 sources, both published and unpublished, together with new sub-Doppler linewidth measurements of about 15,000 A<--X transitions using polarization spectroscopy. We also present new ab initio results for the diagonal and off-diagonal spin-orbit functions. The discrete variable representation is used in conjunction with Hund's case a potentials plus spin-orbit effects to model data extending from v=0 to very close to the 3 2S+3 2P12 limit. Empirical estimates of the spin-orbit functions agree well with the ab initio functions for the accessible values of R. The potential function for the A state includes an exchange potential for S+P atoms, with a fitted coefficient somewhat larger than the predicted value. Observed and calculated term values are presented in an auxiliary (EPAPS) file as a database for future studies on Na2.
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Affiliation(s)
- P Qi
- Physics Department, Temple University, Philadelphia, Pennsylvania 19122-6082, USA
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Kubkowska M, Grochola A, Jastrzebski W, Kowalczyk P. The C1Πu and states in Li2: Experiment and comparison with theory. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Lerch EBW, Dai X, Gilb S, Torres EA, Leone SR. Control of Li2 wave packet dynamics by modification of the quantum mechanical amplitude of a single state. J Chem Phys 2006; 124:044306. [PMID: 16460161 DOI: 10.1063/1.2158990] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Sequences of pulses with different spectra are used to control rotational wave packet dynamics in Li(2) by exploiting quantum interference phenomena. Wave packet superpositions are excited in a two-step resonant Raman process by two different pulses. Interferences between individual states shared by both wave packets can be used to enhance or destroy specific components of a superposition by varying the time delay between the pulses and/or the relative phase within the pulses. Elimination of selected quantum beats is achieved by greater than 94% for each case. A simple, yet effective, method for generating different color phase-locked pairs of laser pulses in a liquid-crystal pulse shaper setup without the need for interferometric stabilization schemes is described. The ability to manipulate single states of a superposition is an important advancement for intuitive control schemes and provides a potential new approach for initialization schemes in the field of quantum information.
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Affiliation(s)
- Eliza-Beth W Lerch
- Department of Chemistry, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA
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Lee SY, Boo BH, Kang HK, Kang D, Judai K, Nishijo J, Nishi N. Reexamination of the structures and energies of Li2C2 and Li4C4. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.05.123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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23
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Manaa MR, Ross AJ, Martin F, Crozet P, Lyyra AM, Li L, Amiot C, Bergeman T. Spin–orbit interactions, new spectral data, and deperturbation of the coupled b 3∏u and A 1∑u+ states of K2. J Chem Phys 2002. [DOI: 10.1063/1.1522716] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mirowski E, Stauffer HU, Ballard JB, Zhang B, Hetherington CL, Leone SR. Effect of nonresonant frequencies on the enhancement of quantum beat amplitudes in rovibrational states of Li2: The role of state spacing. J Chem Phys 2002. [DOI: 10.1063/1.1522717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wang X, Magnes J, Lyyra AM, Ross AJ, Martin F, Dove PM, Le Roy RJ. Born–Oppenheimer breakdown in a combined-isotopomer analysis of the A 1Σu+–X 1Σg+ system of Li2. J Chem Phys 2002. [DOI: 10.1063/1.1514670] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ballard JB, Stauffer HU, Amitay Z, Leone SR. Optimization of wave packet coefficients in Li2 using an evolutionary algorithm: The role of resonant and nonresonant wavelengths. J Chem Phys 2002. [DOI: 10.1063/1.1429955] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Stauffer HU, Ballard JB, Amitay Z, Leone SR. Simultaneous phase control of Li2 wave packets in two electronic states. J Chem Phys 2002. [DOI: 10.1063/1.1427708] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Li L, Kasahara S, Kabir MH, Sahashi Y, Baba M, Katô H. Nonadiabatic g–u mixing of the F 1Σg+ and 2 1Σu+ states of 6Li7Li. J Chem Phys 2001. [DOI: 10.1063/1.1374240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Lazarov G, Lyyra AM, Li L. Enhanced Access to the Dark Triplet States of (7)Li(2) through New Singlet-Triplet A(1)Sigma(+)(u) approximately b(3)Pi(u) Perturbation Window Levels: Perturbation-Facilitated Optical-Optical Double Resonance Study of the 2(3)Sigma(+)(g) State. JOURNAL OF MOLECULAR SPECTROSCOPY 2001; 205:73-80. [PMID: 11148109 DOI: 10.1006/jmsp.2000.8238] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two new pairs of singlet-triplet A(1)Sigma(+)(u) approximately b(3)Pi(u) mixed levels of (7)Li(2) have been observed and used here as "window" levels in cw perturbation-facilitated optical-optical double-resonance (PFOODR) experiments. Previously, only one b(3)Pi(u) vibrational level, v = 19, was known to mix with the singlet A(1)Sigma(+)(u) v = 13 level, resulting in three perturbed A approximately b pairs [L. Li, T. An, T.-J. Whang, A. M. Lyyra, W. C. Stwalley, R. W. Field, and R. A. Bernheim, J. Chem. Phys. 96, 3342 (1992)]. The scarcity of window levels and the resulting difficulty in accessing the dark triplet states of Li(2) is caused by the weak spin-orbit interaction of Li(2). The two new mixed b(3)Pi(u) v = 15 and 22 levels reported here enhance access to the dark triplet state manifold through expansion of the Franck-Condon overlap factor range. Furthermore, the earlier range of accessible rotational levels, N = 5, 7, and 10, is now expanded to include N = 8 and N = 16, thereby allowing for more reliable determination of the excited triplet states rotational structure. To demonstrate the importance of the new A(1)Sigma(+)(u) approximately b(3)Pi(u) mixed levels, we have studied the 2(3)Sigma(+)(g) state by cw PFOODR fluorescence excitation spectroscopy. New molecular constants and RKR potential curve have been determined. As previously reported [L. Li, G. Lazarov, and A. M. Lyyra, J. Mol. Spectrosc. 191, 387 (1998)], the 2(3)Sigma(+)(g) state interacts with the repulsive 1(3)Pi(g) state by L-uncoupling and predissociates. We show that some 2(3)Pi(g) levels predissociate accidentally by the 1(3)Pi(g) state via the 2(3)Sigma(+)(g) state through L-uncoupling. Copyright 2001 Academic Press.
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Affiliation(s)
- G Lazarov
- Department of Physics, Temple University, Philadelphia, Pennsylvania, 19122
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Van Hooydonk G. Gauge symmetry, chirality and parity effects in four-particle systems: Coulomb's law as a universal function for diatomic molecules. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2000; 56A:2273-2331. [PMID: 11075672 DOI: 10.1016/s1386-1425(00)00298-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Following recent work in search for a universal function (Van Hooydonk, Eur. J. Inorg. Chem., (1999), 1617), we test four symmetric +/- a(n)Rn potentials for reproducing molecular potential energy curves (PECs). Classical gauge symmetry for 1/R-potentials results in generic left right asymmetric PECs. A pair of symmetric perturbed Coulomb potentials is quantitatively in accordance with observed PECs. For a bond, a four-particle system, charge inversion (a parity effect, atom chirality) is the key to explain this shape generically. A parity adapted Hamiltonian reduces from ten to two terms and to a soluble Bohr-like formula, a Kratzer (1 - Re/R)2 potential. The result is similar to the combined action of spin and wave function symmetry upon the Hamiltonian in Heitler-London theory. Analytical perturbed Coulomb functions varying with (1 - Re/R) scale attractive and repulsive branches of PECs for 13 bonds H2, HF, LiH, KH, AuH, Li2, LiF, KLi, NaCs, Rb2, RbCs, Cs2 and I2 in a single straight line. The 400 turning points for 13 bonds are reproduced with a deviation of 0.007 A at both branches. For 230 points at the repulsive side, the deviation is 0.003 A. The perturbed electrostatic Coulomb law is a universal molecular function. Ab initio zero molecular parameter functions give PECs of acceptable quality, just using atomic ionisation energies. The function can be used as a model potential for inverting levels and gives a first principle's comparison of short- and long-range interactions, important for the study of cold atoms. Wave-packet dynamics, femto-chemistry applied to the crossing of covalent and ionic curves, can provide evidence for this theory. We anticipate this scale/shape invariant scheme applies to smaller scales in nuclear and high-energy particle physics. For larger gravitational scales (Newton 1/R potentials), problems with super-unification are discussed. Reactions between hydrogen and antihydrogen, feasible in the near future, will probably produce normal H2.
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Affiliation(s)
- G Van Hooydonk
- Department of Library Sciences, Ghent University, Belgium.
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Stewart B, Magill PD, Pritchard DE. Quasi-Resonant Vibration−Rotation Transfer in Inelastic Li2*−Ne Collisions. J Phys Chem A 2000. [DOI: 10.1021/jp001445c] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brian Stewart
- Department of Physics, Wesleyan University, Middletown, Connecticut 06549
| | | | - David E. Pritchard
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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Pashov A, Jastrzȩbski W, Kowalczyk P. The Li2 F 1Σg+ “shelf” state: Accurate potential energy curve based on the inverted perturbation approach. J Chem Phys 2000. [DOI: 10.1063/1.1311297] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Kasahara S, Kowalczyk P, Kabir MH, Baba M, Katô H. Doppler-free UV-visible optical–optical double resonance polarization spectroscopy of the 2 1Σu+ double minimum state and the C 1Πu state of Li2. J Chem Phys 2000. [DOI: 10.1063/1.1308089] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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36
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Fuchs M, Toennies JP. Electron impact ionisation cross sections of highly vibrationally excited Li2molecules. ACTA ACUST UNITED AC 1999. [DOI: 10.1088/0022-3700/20/3/021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Wang X, Yang J, Qi J, Lyyra AM. Precise Molecular Constants for the 6Li2 A1Sigma+u-X1Sigma+g System by Sub-Doppler Polarization Spectroscopy. JOURNAL OF MOLECULAR SPECTROSCOPY 1998; 191:295-305. [PMID: 9753564 DOI: 10.1006/jmsp.1998.7645] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report here new and more accurate molecular constants from sub-Doppler polarization spectroscopy of the A1Sigma+u-X1Sigma+g system of 6Li2 using single mode cw dye lasers. These new constants cover the range of vibrational levels from v" = 0-8 in the ground state and v' = 0-24 in the excited state. New molecular constants and RKR potential energy curves for the A1Sigma+u and X1Sigma+g states are given. The Te value for the A1Sigma+u state is 14068.043(34) cm-1. The analysis indicates that there is a noticeable breakdown of the Born-Oppenheimer approximation for the 6Li2 and 7Li2 isotopomers. Copyright 1998 Academic Press.
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Affiliation(s)
- X Wang
- Physics Department, Temple University, Philadelphia, Pennsylvania, 19122
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Antonova S, Urbanski K, Lyyra A, Spano F, Li L. State to state collision energy transfer in singlet states of Li2. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00071-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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39
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Penotti FE. On the effect of potential-energy cubic-spline interpolation error on Numerov-Cooley diatomic rovibrational levels. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0097-8485(97)00037-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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40
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Li L, Yiannopoulou A, Urbanski K, Lyyra AM, Ji B, Stwalley WC, An T. Hyperfine structures of the 7Li2 b3Πu, 23Πg, and 33Πg states: Continuous wave perturbation facilitated optical–optical double resonance spectroscopy. J Chem Phys 1996. [DOI: 10.1063/1.473003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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41
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Williams RM, Papanikolas JM, Rathje J, Leone SR. Quantum-state-resolved 2-level femtosecond rotational coherence spectroscopy: Determination of rotational constants at medium and high J in Li2, a simple diatomic system. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(96)00979-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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42
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Distributed approximating functional approach to fitting and predicting potential surfaces. 1. Atom-atom potentials. Chem Phys Lett 1996. [DOI: 10.1016/s0009-2614(96)00150-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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44
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Kaplan IG, Hernández-Cobos J, Ortega-Blake I, Novaro O. Many-body forces and electron correlation in small metal clusters. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 53:2493-2500. [PMID: 9913162 DOI: 10.1103/physreva.53.2493] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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45
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Urbanski K, Antonova S, Yiannopoulou A, Lyyra AM, Li L, Stwalley WC. All optical triple resonance spectroscopy of the A 1Σ+u state of 7Li2. J Chem Phys 1996. [DOI: 10.1063/1.471105] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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46
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Gao Y, Gorgone PS, Davis S, McCall EK, Stewart B. Dependence of level‐resolved energy transfer on initial vibrational level in Li2A1Σu+−Ne collisions. J Chem Phys 1996. [DOI: 10.1063/1.470908] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Weyh T, Ahmed K, Demtröder W. Radiative lifetimes, quenching cross sections and population mechanisms of the C1Πu, 23Πg and 1 3Δg states of 7Li2. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(95)01326-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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48
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Abraham ERI, Ritchie NWM, McAlexander WI, Hulet RG. Photoassociative spectroscopy of long‐range states of ultracold 6Li2 and 7Li2. J Chem Phys 1995. [DOI: 10.1063/1.470296] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Papanikolas JM, Williams RM, Kleiber PD, Hart JL, Brink C, Price SD, Leone SR. Wave‐packet dynamics in the Li2 E(1Σ+g) shelf state: Simultaneous observation of vibrational and rotational recurrences with single rovibronic control of an intermediate state. J Chem Phys 1995. [DOI: 10.1063/1.470301] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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50
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Côté R, Dalgarno A, Sun Y, Hulet RG. Photoabsorption by ultracold atoms and the scattering length. PHYSICAL REVIEW LETTERS 1995; 74:3581-3583. [PMID: 10058241 DOI: 10.1103/physrevlett.74.3581] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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