Highly efficient implementation of the analytical gradients of pseudospectral time-dependent density functional theory

Yixiang Cao; Mathew D Halls; Richard A Friesner

doi:10.1063/5.0055379

Highly efficient implementation of the analytical gradients of pseudospectral time-dependent density functional theory

J Chem Phys. 2021 Jul 14;155(2):024115. doi: 10.1063/5.0055379.

Authors

Yixiang Cao¹, Mathew D Halls², Richard A Friesner³

Affiliations

¹ Schrödinger Inc., 120 West 45th Street, Tower 45, 17th Floor, New York, New York 10036, USA.
² Schrödinger Inc., 10201 Wateridge Circle, Suite 220, San Diego, California 92121, USA.
³ Department of Chemistry, Columbia University, New York, New York 10027, USA.

PMID: 34266272
DOI: 10.1063/5.0055379

Abstract

The accuracy and efficiency of time-dependent density functional theory (TDDFT) excited state gradient calculations using the pseudospectral method are presented. TDDFT excited state geometry optimizations of the G2 test set molecules, the organic fluorophores with large Stokes shifts, and the Pt-complexes show that the pseudospectral method gives average errors of 0.01-0.1 kcal/mol for the TDDFT excited state energy, 0.02-0.06 pm for the bond length, and 0.02-0.12° for the bond angle when compared to the results from conventional TDDFT. TDDFT gradient calculations of fullerenes (C_n, n up to 540) with the B3LYP functional and 6-31G** basis set show that the pseudospectral method provides 8- to 14-fold speedups in the total wall clock time over the conventional methods. The pseudospectral TDDFT gradient calculations with a diffuse basis set give higher speedups than the calculations for the same basis set without diffuse functions included.