Comparative study of Green's function matrix elements and charge transfers obtained from different partitioning schemes of molecular charge in hydrogen-bonded complexes
RHF and MP2 ab initio molecular orbital calculations using the 4-31G**, 6-311G** and cc-pVTZ basis sets have revealed that the Green's function matrix element (G D,A) values show a good correlation with the amount of intermolecular transferred charges obtained from different charge partitioning...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Sociedade Brasileira de Química
2006-01-01
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| Series: | Journal of the Brazilian Chemical Society |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532006000200004 |
| Summary: | RHF and MP2 ab initio molecular orbital calculations using the 4-31G**, 6-311G** and cc-pVTZ basis sets have revealed that the Green's function matrix element (G D,A) values show a good correlation with the amount of intermolecular transferred charges obtained from different charge partitioning schemes for the CNH?CNH, NCH?CNH, CNH?NCH and NCH?NCH hydrogen bonded complexes. This is evident specially when the hydrogen bond distance is progressively increased from the equilibrium position until 4.5 Å. However, G D,A values show a better linear correlation with deltaQ values using corrected Mülliken charges, which are obtained from the charge-charge flux-overlap (CCFO) model for infrared intensities. In this case, both G D,A and deltaQcorr form two practically superposed exponential curves. On the other hand, G D,A values show a smaller agreement with deltaQ values obtained from atomic charges derived from natural bonding orbitals. This is clearly verified when considering the first order exponential decay rate of G D,A versus deltaQ obtained from different charge partitioning schemes. |
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| ISSN: | 0103-5053 1678-4790 |