TY - JOUR
T1 - Relativistic coupled cluster calculation of Mössbauer isomer shifts of iodine compounds
AU - Zelovich, Tamar
AU - Borschevsky, Anastasia
AU - Eliav, Ephraim
AU - Kaldor, Uzi
N1 - Publisher Copyright:
© 2016 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2017/1/17
Y1 - 2017/1/17
N2 - Mössbauer isomer shifts of 129I and 127I in the ICl, IBr and I2 molecules are studied. Filatov's formulation is used, based on calculating the electronic energy change of the two systems involved in the Mössbauer γ transition, the source and absorber. The energy difference between the transitions in the two systems determines the shift. The effects of relativity and electron correlation on the shifts are investigated. The exact two-component (X2C) and the four-component relativistic schemes give virtually identical results; the non-relativistic approach yields about 50% of the relativistic shifts. Electron correlation is included by coupled-cluster singles-and-doubles with perturbative triples [CCSD(T)]; it reduces Hartree–Fock shifts by 15%–20%. Basis sets are increased until the isomer shifts converge. The final results, calculated with the converged basis in the framework of the X2C Hamiltonian and CCSD(T) correlation, give an agreement of 10% or better with experimental data.
AB - Mössbauer isomer shifts of 129I and 127I in the ICl, IBr and I2 molecules are studied. Filatov's formulation is used, based on calculating the electronic energy change of the two systems involved in the Mössbauer γ transition, the source and absorber. The energy difference between the transitions in the two systems determines the shift. The effects of relativity and electron correlation on the shifts are investigated. The exact two-component (X2C) and the four-component relativistic schemes give virtually identical results; the non-relativistic approach yields about 50% of the relativistic shifts. Electron correlation is included by coupled-cluster singles-and-doubles with perturbative triples [CCSD(T)]; it reduces Hartree–Fock shifts by 15%–20%. Basis sets are increased until the isomer shifts converge. The final results, calculated with the converged basis in the framework of the X2C Hamiltonian and CCSD(T) correlation, give an agreement of 10% or better with experimental data.
KW - Mössbauer isomer shifts
KW - iodine compounds
KW - relativistic effects
UR - http://www.scopus.com/inward/record.url?scp=84976401899&partnerID=8YFLogxK
U2 - 10.1080/00268976.2016.1203036
DO - 10.1080/00268976.2016.1203036
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AN - SCOPUS:84976401899
SN - 0026-8976
VL - 115
SP - 138
EP - 143
JO - Molecular Physics
JF - Molecular Physics
IS - 1-2
ER -