First and second-order properties of charge-localized and Frost-localized orbitals

Two methods of localization of Frost-model molecular orbitals are considered, both of which are extremely easy to apply, requiring the evaluation of only one-election integrals. The chargelocalization criterion can be used with any single-determinant wavefunction, but when applied to the Frost model it yields similar orbitals to those got by orthonormalizing the basis of floating spherical gaussians, while maintaining their localized feature. Properties of charge-localized orbitals are calculated for NH3, H2O, CH4, C2H6.