TY - JOUR
T1 - Localized Active Space Pair-Density Functional Theory
AU - Pandharkar, Riddhish
AU - Hermes, Matthew R.
AU - Cramer, Christopher J.
AU - Truhlar, Donald G.
AU - Gagliardi, Laura
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/5/11
Y1 - 2021/5/11
N2 - Accurate quantum chemical methods for the prediction of spin-state energy gaps for strongly correlated systems are computationally expensive and scale poorly with the size of the system. This makes calculations for many experimentally interesting molecules impractical even with abundant computational resources. Previous work has shown that the localized active space (LAS) self-consistent field (SCF) method can be an efficient way to obtain multiconfiguration SCF wave functions of comparable quality to the corresponding complete active space (CAS) ones. To obtain quantitative results, a post-SCF method is needed to estimate the complete correlation energy. One such method is multiconfiguration pair-density functional theory (PDFT), which calculates the energy based on the density and on-top pair density obtained from a multiconfiguration wave function. In this work, we introduce localized-active-space PDFT, which uses a LAS wave function for subsequent PDFT calculations. The method is tested by computing spin-state energies and gaps in conjugated organic molecules and a bimetallic compound and comparing to the corresponding CAS-PDFT values.
AB - Accurate quantum chemical methods for the prediction of spin-state energy gaps for strongly correlated systems are computationally expensive and scale poorly with the size of the system. This makes calculations for many experimentally interesting molecules impractical even with abundant computational resources. Previous work has shown that the localized active space (LAS) self-consistent field (SCF) method can be an efficient way to obtain multiconfiguration SCF wave functions of comparable quality to the corresponding complete active space (CAS) ones. To obtain quantitative results, a post-SCF method is needed to estimate the complete correlation energy. One such method is multiconfiguration pair-density functional theory (PDFT), which calculates the energy based on the density and on-top pair density obtained from a multiconfiguration wave function. In this work, we introduce localized-active-space PDFT, which uses a LAS wave function for subsequent PDFT calculations. The method is tested by computing spin-state energies and gaps in conjugated organic molecules and a bimetallic compound and comparing to the corresponding CAS-PDFT values.
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U2 - 10.1021/acs.jctc.1c00067
DO - 10.1021/acs.jctc.1c00067
M3 - Article
C2 - 33900078
AN - SCOPUS:85105974249
SN - 1549-9618
VL - 17
SP - 2843
EP - 2851
JO - Journal of Chemical Theory and Computation
JF - Journal of Chemical Theory and Computation
IS - 5
ER -