AB-INITIO CLOPPA DECOMPOSITION OF THE STATIC MOLECULAR POLARIZABILITYTENSOR

An ab initio method based on CLOPPA-IPPP (contributions from localized orbitals within the polarization propagator approach-inner projection s of the polarization propagator) for analysing the static molecular p olarizability tensor is presented. This method makes use of the polari zation propagator formalism, together with localized molecular orbital s which closely resemble chemical functions, to decompose each compone nt of the polarizability tensor into contributions arising from differ ent molecular fragments. Within this approach, 'local' and 'mutual' po larizabilities are defined, which are useful for studying the molecula r response to an inhomogeneous electric field. In order to exemplify i ts capabilities, this method is applied to the study of the polarizabi lity tensor in the series ethane, ethylene and acetylene.