Quantum Chemistry for Large Molecules: Linear-Scaling Mean-Field and Correlated Approaches

摘要

A brief review of our work to attain linear scaling computational effort for Hartree-Fock (HF), Density-Functional Theory (DFT), and second-order Moller-Plesset perturbation theory (MP2) is presented. While we describe linear-scaling methods for calculating molecular response properties of large molecules for HF and DFT, we focus on energetics and energy gradients at the MP2 level. A key element of our approach is the use of multipole-based integral estimates (MBIE) which allow to rigorously preselect four-center two-electron integrals ubiquitous in quantum chemistry. MBIE does not only account for the exponential coupling between basis functions forming charge distributions, but also for the 1/R coupling between the charge distributions. In context of an atomic-orbital based formulation of MP2 theory, the MBIE preselection of significant contributions opens the way to achieve linear scaling, while numerical errors remain fully controlled. The largest system computed sofar at the MP2 level is a DNA strand with 16 base pairs, 1052 atoms, and 10 674 basis functions.