Non-iterative local second order Moller-Plesset theory

Second order Moller-Plesset perturbation theory (MP2) is formulated in terms of atom-centred occupied and virtual orbitals. Both the occupied and the Virtual orbitals are non-orthogonal. A new parameter-free atoms-in-molecules local approximation is employed to reduce the cost of the calculation to cubic scaling, and a quasi-canonical two-particle basis is introduced to enable the solution of the local MP equations via explicit matrix diagonalisation rather than iteration. (C) 1998 Elsevier Science B.V.