Approaching the basis set limit for DFT calculations using an environment-adapted minimal basis with perturbation theory: Formulation, proof of concept, and a pilot implementation

Yuezhi Mao; Paul R Horn; Narbe Mardirossian; Teresa Head-Gordon; Chris-Kriton Skylaris; Martin Head-Gordon

doi:10.1063/1.4959125

Approaching the basis set limit for DFT calculations using an environment-adapted minimal basis with perturbation theory: Formulation, proof of concept, and a pilot implementation

J Chem Phys. 2016 Jul 28;145(4):044109. doi: 10.1063/1.4959125.

Authors

Yuezhi Mao¹, Paul R Horn¹, Narbe Mardirossian¹, Teresa Head-Gordon², Chris-Kriton Skylaris³, Martin Head-Gordon¹

Affiliations

¹ Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA.
² Department of Chemistry, University of California, Berkeley, California 94720, USA.
³ School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom.

PMID: 27475350
DOI: 10.1063/1.4959125

Abstract

Recently developed density functionals have good accuracy for both thermochemistry (TC) and non-covalent interactions (NC) if very large atomic orbital basis sets are used. To approach the basis set limit with potentially lower computational cost, a new self-consistent field (SCF) scheme is presented that employs minimal adaptive basis (MAB) functions. The MAB functions are optimized on each atomic site by minimizing a surrogate function. High accuracy is obtained by applying a perturbative correction (PC) to the MAB calculation, similar to dual basis approaches. Compared to exact SCF results, using this MAB-SCF (PC) approach with the same large target basis set produces <0.15 kcal/mol root-mean-square deviations for most of the tested TC datasets, and <0.1 kcal/mol for most of the NC datasets. The performance of density functionals near the basis set limit can be even better reproduced. With further improvement to its implementation, MAB-SCF (PC) is a promising lower-cost substitute for conventional large-basis calculations as a method to approach the basis set limit of modern density functionals.