Gaussian basis sets for all-electron excited-state calculations of large molecules

TL;DR

This paper presents a new family of augmented Gaussian basis sets optimized for excited-state calculations on large molecules, achieving fast convergence and high accuracy in $GW$ and Bethe-Salpeter energies.

Contribution

Introduction of augmented MOLOPT basis sets specifically optimized for excited-state calculations on large molecules, improving convergence and computational efficiency.

Findings

Achieve 60 meV mean absolute deviation for $GW$ HOMO-LUMO gaps.

Demonstrate $GW$ calculations on nanographenes with 9224 atoms using 34300 core hours.

Maintain low condition numbers for numerical stability.

Abstract

We introduce a family of all-electron Gaussian basis sets, augmented MOLOPT, optimized for excited-state calculations on large molecules. We generate these basis sets by augmenting existing STO-3G, STO-6G, and MOLOPT basis sets optimized for ground state energy calculations. The augmented MOLOPT basis sets achieve fast convergence of $GW$ gaps and Bethe-Salpeter excitation energies, while maintaining low condition numbers of the overlap matrix to ensure numerical stability. For $GW$ HOMO-LUMO gaps, the double-zeta augmented MOLOPT basis yields a mean absolute deviation of 60 meV to the complete basis set limit. The basis set convergence for excitation energies from time-dependent density functional theory and the Bethe-Salpeter equation is similar. We use our smallest generated augmented MOLOPT basis (aug-SZV-MOLOPT-ae-mini) to demonstrate $GW$ calculations on nanographenes with 9224 atoms requiring only 34300 core hours of computational resources.