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Atomic charges derived from different methods: A comparative study applied to SO 2 heterocycles
Author(s) -
Rozas Isabel
Publication year - 1997
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/(sici)1097-461x(1997)62:5<477::aid-qua4>3.0.co;2-t
Subject(s) - electronegativity , chemistry , mulliken population analysis , dipole , computational chemistry , atomic charge , molecular orbital , molecule , ab initio , charge (physics) , population , atomic orbital , atomic physics , density functional theory , physics , quantum mechanics , organic chemistry , electron , demography , sociology
Atomic charges were calculated at ab initio level using different methods of charge determination to compare them and estimate their utility in the electronic description of heterocycles containing the SO 2 moiety. Those procedures implemented on the Gaussian92 program were included [Mulliken population analysis, Weinhold‐Reed natural population analysis (NPA) and CHELPG]. The first two are based on the molecular orbitals while in the third one the charges are derived by fitting the electrostatic potential. Two sets of compounds were chosen to represent the different characteristics of the SO 2 heterocycles studied: simpler five‐member heterocycles and SO 2 small derivatives. These molecules were optimized at the HF/6‐31G * level and their energy evaluated by a punctual calculation MP2/6‐31G * //HF/6‐31G * . The dipole moments for these molecules were obtained by using all the methods previously mentioned and compared with the SCF, MP2, and experimental dipole moments. The influence on the charges of some atoms by changing the electronegativity of neighboring atoms has also been investigated for these compounds. The results obtained show that the best methods to describe the electronic distribution of the oxathiole studied are Mulliken and CHELPG at the MP2 level of calculation. The charge distributions obtained with these two methods for these particular heterocycles are discussed. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 62: 477–487, 1997