A localized basis that allows fast and accurate second order Moller-Plesset
We present a method for computing a basis of localized orthonormal orbitals (both occupied and virtual), in whose representation the Fock matrix is extrememly diagonal-dominant. The existence of these orbitals is shown empiricaly to be sufficient for achieving highly accurate MP@ energies, calculated according to Kapuy's method. This method (which we abbreviate KMP2), which involves a different partitioning of the n-electron Hamiltonian, scales at most quadratically with potential for linearity in the number of electrons. As such, we believe the KMP2 algorithm presented here could be the basis of a viable approach to local correlation calculations.