Recently developed density functionals have impressive accuracy for both thermochemistry (TC) and non-covalent interactions (NC), but only when very large basis sets are used. To approach the basis set limit with potentially lower computational effort, a new SCF scheme with minimal adaptive basis (MAB) functions variationally optimized on each atomic site is proposed. The desired accuracy can be obtained by applying a perturbative correction (PC) to SCF performed in the MAB. Compared to exact SCF results using the modern B97M-V density functional, using this MAB-SCF (PC) approach with the same target basis set produces &lt; 0.1 kcal/mol RMS errors for tested TC data, and less than 0.05 kcal/mol for the NC data. Hence the performance of modern density functionals near the basis set limit can be well reproduced. With further improvement to its implementation, MAB-SCF (PC) could be a promising low-cost substitute for its conventional counterpart to viably approach the basis set limit of modern density functionals.

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

252nd National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.