Alternative linear-scaling methodology for the second-order Moller-Plesset perturbation calculation based on the divide-and-conquer method

摘要

A new scheme for obtaining the approximate correlation energy in the divide-and-conquer(DC)method of Yang[Phys.Rev.Lett.66,1438(1991)]is presented.In this method,the correlation energy of the total system is evaluated by summing up subsystem contributions,which are calculated from subsystem orbitals based on a scheme for partitioning the correlation energy.We applied this method to the second-order M0ller-Plesset perturbation theory(MP2),which we call DC-MP2.Numerical assessment revealed that this scheme provides a reliable correlation energy with significantly less computational cost than the conventional MP2 calculation.