Theoretical interpretation of Grimme's spin-component-scaled second order Moller-Plesset theory

It is shown that spin-component-scaled second order Moller-Plesset theory proposed by Grimme [J. Chem. Phys. 118, 9095 (2003)] can be interpreted as a two-parameter scaling of the zero order Hamiltonian, a generalization of the approach reported by Feenberg [Phys. Rev. 103, 1116 (1956)]. (c) 2006 American Institute of Physics.