Chemistry, Ames Laboratory
Journal or Book Title
Journal of Chemical Physics
A systematic study of the deviation from size consistency of the multireference second-order Møller-Plesset perturbation theory (MRMP2) method is presented. The size-consistency error is shown to depend on the number of monomers in a supermolecule calculation, size of basis set, number of correlated valence electrons, and size of active space. HF, F2, and N2 are used as test cases, with stretched bonds, to include simple, well-defined multireference character. This is essential in ensuring that MRMP2 is being tested as a multireference method. It is concluded that the MRMP2 and other multireference perturbation theory methods can exhibit significant size-consistency errors, and that the size of the error depends on the manner in which the perturbation theory is implemented.
Copyright 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
American Institute of Physics
Rintelman, Jamie Marie; Adamovic, Ivana; Varganov, Sergey Aleksandrovich; and Gordon, Mark S., "Multireference Second-Order Perturbation Theory: How Size Consistent is “Almost Size Consistent”" (2005). Chemistry Publications. 436.