Study of electron-transfer reactions using the oxidation-state constrained density functional theory (OS-CDFT) method*

Electron transfer is fundamental process that occurs ubiquitously from energy conversion, molecular electronics to biochemistry. Effective generation of the diabatic states is needed for determination of parameters like reorganization energies and electronic coupling constants which are important for electron transfer study. Here, we discuss the recently developed oxidation-state constrained density functional theory (OS-CDFT) method [1] which specifically controls the oxidation states of transition metal ions. This is based on the previous approach for oxidation state determination [2]. Under OS-CDFT, we can obtain forces on ions for structural optimization. The electronic coupling constant can also be evaluated from the diabatic states. After that, we introduce its application to problems like electron transfer between solvated ferrous and ferric ions, polaron hopping in TiO₂ and in BiVO₄, and photoexcited electron transfer.

[1] C. Ku and P. H.-L. Sit. J. Chem. Theory Comput. 15, 4781 (2019)
[2] P. H.-L. Sit, R. Car, M. H. Cohen and A. Selloni. Inorg. Chem., 50, 10259 (2011).