Semiempirical implementation of strictly localized geminals for analysis of molecular electronic structure

Approximate electronic trial wave function taken as the antisymmetrized pro duct of strictly localized geminals (APSLG) is implemented for semiempirica l analysis of molecular electronic structure of "organic" compounds and for calculations of their heats of formation. This resulted in an O(N)-scaling method. Using the MINDO/3 form of the semiempirical Hamiltonian with repar ameterized beta (AB) values in combination with the APSLG form of the wave function yields the computational procedure BF'98. Calculations on the heat s formation and the equilibrium geometries for a wide range of molecules sh ow that the APSLG-MINDO/3 approach is more favorable than its self-consiste nt field-based counterpart. Also, the APSLG formalism allows to interpret m olecular electronic wave function in chemically sensible terms. (C) 2001 Jo hn Wiley & Sons, Inc.