Iron(II) porphyrins are critical components in enzymes and synthetic catalysts. Computationally determining the spin-state energetic ordering for even the basic, unsubstituted iron(II) porphyrin (FeP) is inherently challenging due to its large degree of electron correlation. Here multiconfigurational pair-density functional theory (MCPDFT), a method shown to be capable of accurately capturing correlation, is applied to FeP using reference wave functions from restricted active-space self-consistent field theory (RASSCF) and density renormalization group theory (DMRG). The DMRG(40e, 42o) and RASSCF(40, 2, 2; 16, 6, 20) active spaces used here are the largest yet applied in MC-PDFT calculations of FeP spin-state energetics. Also, for the first time, hybrid MCPDFT functionals are used to calculate FeP spin-state energetics; general trends in the energetics emerge within sets of on-top functionals that have the same hybrid parameter λ.

Spin-state orderings in iron(II) porphyrin determined by hybrid multiconfigurational pair-density functional theory with expanded RAS and DMRG active spaces

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

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