Topologically partitioned dynamic polarizabilities using the theory of atoms in molecules.
In: Canadian Journal of Chemistry, Jg. 74 (1996) ; Nr. 6, S. 976-987
Zeitschriftenaufsatz / Fach: Chemie
Frequency-dependent distributed polarizabilities have been detd. from time-dependent Hartree-Fock calcns., using the partitioning of the mol. space suggested by Bader's topol. theory of atoms in mols. The basis set dependence of the distributed dynamic polarizabilities is analyzed in terms of the first few Cauchy moments, for the carbon monoxide, water, cyanogen, urea, and benzene mols. Two alternative relocalization schemes have been considered in order to reduce the no. of distributed dynamic polarizability parameters. The first one, closely related to the at. polarizability model of Bader, leads to at. charge-dipole and dipole-dipole polarizabilities, describing the response of the mol. charge distribution to a uniform external field, in terms of at. charges and dipoles. The second scheme, similar to that suggested by Stone, retains the fully distributed description of the dynamic charge-flow polarizabilities, while all two-center dipole-dipole and charge-dipole contributions are condensed in one-center dynamic dipole-dipole polarizabilities.