123rd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Physical Chemists II
Room No. Room 305+306
Time THU 10:30-10:39
Code PHYS2.O-4
Subject Eliminating spin-contamination of spin-flip time dependent density functional theory within linear response formalism by the use of zeroth-order mixed-reference (MR) reduced density matrix
Authors Seunghoon Lee, Sangyoub Lee, Cheol Ho Choi1,*
Division of Chemistry, Seoul National University, Korea
1Department of Chemistry, Kyungpook National University, Korea
Abstract The use of mixed-reference (MR) reduced density matrix, which combines reduced density matrices of the MS = +1 and -1 triplet-ground states, is proposed in the context of the collinear SF-TDDFT methodology. The time-dependent Kohn-Sham equation with the mixed state is solved by the use of spinor-like open-shell orbitals within the linear-response formalism, which enables to generate additional configurations in the realm of TDDFT. The resulting MRSF-TDDFT computational scheme has several advantages before the conventional collinear SF-TDDFT. The spin-contamination of the response states of SF-TDDFT is nearly removed. This considerably simplifies the identification of the excited states, especially in the "black-box" type applications, such as the automatic geometry optimization, reaction path following, or molecular dynamics simulations. With the new methodology, the accuracy of the description of the excited states is improved as compared to the collinear SF-TDDFT. Several examples, which include systems typified by strong non-dynamic correlation, orbital (near) degeneracy, conical intersections, and non-adiabatic dynamic simulation, are given to illustrate the performance of the new method.
E-mail seunghoonlee89@gmail.com