Ab initio linear scaling response theory: Electric polarizability by perturbed projection

TL;DR

This paper introduces a linear scaling ab initio response method using density matrix perturbation theory to efficiently compute electric polarizability, demonstrated on water clusters with accurate, localized response properties.

Contribution

It develops a novel linear scaling response calculation method based on spectral projection and density matrix perturbation theory for ab initio electric polarizability.

Findings

Method achieves linear scaling for response calculations.

Local response exhibits exponential decay, confirming locality.

Demonstrated accuracy on water clusters at RHF/6-31G** level.

Abstract

A linear scaling method for calculation of the static {\em ab inito} response within self-consistent field theory is developed and applied to calculation of the static electric polarizability. The method is based on density matrix perturbation theory [Niklasson and Challacombe, cond-mat/0311591], obtaining response functions directly via a perturbative approach to spectral projection. The accuracy and efficiency of the linear scaling method is demonstrated for a series of three-dimensional water clusters at the RHF/6-31G** level of theory. Locality of the response under a global electric field perturbation is numerically demonstrated by approximate exponential decay of derivative density matrix elements.