Large-Scale Benchmarking of Multireference Vertical-Excitation Calculations via Automated Active-Space Selection.

ABSTRACT: We have calculated state-averaged complete-active-space self-consistent-field (SA-CASSCF), multiconfiguration pair-density functional theory (MC-PDFT), hybrid MC-PDFT (HMC-PDFT), and n-electron valence state second-order perturbation theory (NEVPT2) excitation energies with the approximate pair coefficient (APC) automated active-space selection scheme for the QUESTDB benchmark database of 542 vertical excitation energies. We eliminated poor active spaces (20-40% of calculations) by applying a threshold to the SA-CASSCF absolute error. With the remaining calculations, we find that NEVPT2 performance is significantly impacted by the size of the basis set the wave functions are converged in, regardless of the quality of their description, which is a problem absent in MC-PDFT. Additiona

SUBMITTER: King DS 

PROVIDER: S-EPMC9558375 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature