Improved procedure for analysis of electron density redistribution in molecular complexes

摘要

An improved method for theoretical determination of the charge redistribution, i.e., the intramolecular charge shifts, intermolecular charge transfer, and dipole moment enhancement upon complexation, is proposed. This approach consists of counterpoise correction of the basis set superposition error on calculated electron density redistribution in molecular complexes.Ab initioLCAO MO SCF calculations for HFsdot;sdot;sdot;HNH2, H2Osdot;sdot;sdot;HOH, H2Osdot;sdot;sdot;HF, H3Nsdot;sdot;sdot;HF, H3Nsdot;sdot;sdot;LiF, COsdot;sdot;sdot;HCN, H2Ssdot;sdot;sdot;OCHNH2, H2NHCOsdot;sdot;sdot;HSH, lsqb;Mgsdot;sdot;sdot;OHrsqb;+lsqb;HOsdot;sdot;sdot;HOHrsqb;minus;, lsqb;Be(OH)(NH3)2rsqb;+molecular complexes in different basis set have been performed leading to more consistent results in contrast to sometimes largely overestimated uncorrected values reported previously. In addition, the charge redistribution upon complex formation has been analyzed for some dimers in terms of atomic multipole expansion of electron density and difference molecular electrostatic potentials.