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Ground states of molecules. 56. MNDO calculations for molecules containing sulfur
Author(s) -
Dewar Michael J. S.,
McKee Michael L.
Publication year - 1983
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.540040113
Subject(s) - mndo , chemistry , sulfur , standard enthalpy of formation , valence (chemistry) , dipole , ionization energy , ionization , atomic orbital , molecule , computational chemistry , atomic physics , lone pair , ion , physics , organic chemistry , quantum mechanics , electron
MNDO has been extended to sulfur, but without inclusion of 3 d AO s. Calculations are reported for heats of formation, geometries, dipole moments, and ionization energies of a variety of sulfur‐containing molecules. The average discrepancy between calculated and observed heats of formation is larger than for compounds of other elements, a difference probably due, at least partly, to the lower accuracy of the thermochemical data for sulfur compounds. The calculated dipole moments agree well with experiment as do the calculated ionization energies, except for those corresponding to ionization from sulfur “lone‐pair” orbitals which are too high by ca. 1 eV, probably as a result of the neglect in NDDO of interactions between inner and valence shell orbitals. As in the case of other third‐period elements, the calculated heats of formation of compounds of sulfur in its higher valence states (S IV , S VI ) were too positive by large amounts, due presumably to the neglect of 3 d AO s.