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DFT study of the Jahn–Teller impurity Rh 2+ in octahedral symmetry
Author(s) -
Barriuso M. T.,
García Fernández P.,
Aramburu J. A.,
Moreno M.
Publication year - 2002
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.10389
Subject(s) - jahn–teller effect , octahedron , density functional theory , chemistry , anharmonicity , ground state , ion , atomic physics , relaxation (psychology) , atom (system on chip) , bent molecular geometry , molecular physics , physics , computational chemistry , condensed matter physics , social psychology , psychology , organic chemistry , computer science , embedded system
Density functional calculations on clusters involving up to 87 atoms have been carried out for exploring the Jahn–Teller effect in NaCl: Rh 2+ . Due to the flexibility of density functional theory (DFT) methodology, calculations have first been performed for a ground state described by the (3z 2 − r 2 ) 0.5 (x 2 − y 2 ) 0.5 configuration at different values of the Q θ (≈3z 2 − r 2 ) distortion. This electronic configuration allows one to extract the angular frequency, ω E , and anharmonic parameter, A 3 , corresponding to a hypothetical Rh 2+ ion without orbital degeneracy. The calculation on an 87‐atom cluster indicates that ligands have undergone a 10% inward relaxation whereas the first Na + ions along <100> directions experience a small outward relaxation. The latter fact is related to the additional positive charge created through the Na + → Rh 2+ substitution. Calculations at different Q θ (≈3z 2 − r 2 ) distortions for a ground state described by (3z 2 − r 2 ) 1 and (x 2 − y 2 ) 1 configurations have also been carried out and reveal that: (1) the energy minimum for the former electronic configuration corresponds to an elongated octahedron lying ≈200 cm −1 below the minimum associated with (x 2 − y 2 ) 1 configuration displaying a compressed D 4h geometry; (2) the calculated ratio E JT /ℏω E where E JT is the Jahn–Teller energy is found to be equal to 7.5, stressing that the Jahn–Teller effect in NaCl: Rh 2+ is strong. These conclusions concur with available experimental findings. The current calculations reasonably account for the two crystal‐field transitions and the charge transfer band detected through magnetic circular dichroism up to 4.1 eV. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 2003