Multireference M�ller-Plesset perturbation treatment of potential energy curve of N2

A multireference Møller-Plesset (MR-MP) perturbation method, at the second-order level, is applied to the potential energy curve of the ground state of N2, for comparison with a variety of standard ab initio methods. In spite of the drastic simplification, the MR-MP results are very reliable. The energy errors are almost independent of geometry, allowing unbiased treatment of potential energy curves. The potential efficiency and accuracy of the MR-MP approach are emphasized.