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Ab initio SCF and Møller—plesset studies on hexafluorides of selenium and tellurium
Author(s) -
Klobukowski Mariusz
Publication year - 1993
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540141012
Subject(s) - selenium , tellurium , ab initio , computational chemistry , chemistry , chalcogen , ab initio quantum chemistry methods , density functional theory , molecule , crystallography , inorganic chemistry , organic chemistry
SCF and Møller–Plesset calculations were done for the systems AB 6 (TeF 6 and SeF 6 ) and AB 6 E (TeF 2− 6and SeF 2− 6 ) to determine their relative stabilities and geometric structures. The SCF calculations show that both TeF 2− 6(as expected) and SeF 2− 6(despite a small central atom) possess nonoctahedral shapes. However, at the Møller–Plesset level only the TeF 2− 6 ion, studied with a large valence basis set, retains nonoctahedral geometry. The calculated structural parameters of the ion in C 3v symmetry (the bond lengths are 2.212 and 1.975 Å and the bond angles are 104.9 and 83.4 °) differ considerably from the octahedral values (2.101 Å and 90.0°), yet the corresponding total energy is only about 1 kcal/mol smaller. The results show significant dependence of the computational predictions on the basis sets used and indicate the need to include electron correlation effects in the studies devoted to establishing the stereochemical activity of the lone electron pair. © John Wiley & Sons, Inc.