Seminar | April 6 | 5-6 p.m. | 180 Tan Hall
Toru Shiozaki, Pitzer Center for Theoretical Chemistry
Title: "Electronic structure theory for excited state dynamics"
In this talk, I will present two approaches to describing excited state dynamics with a strong emphasis on underlying electronic structure theories. First, I will describe the so-called active-space decomposition (ASD) method, which provides model Hamiltonians for dynamics simulations based on quantum master equations-like approaches. ASD is not only an efficient active space method but also can be seen as chemical generalization of tensor network states. Second, I will present our recent development of multistate CASPT2 nuclear energy gradients and derivative couplings for trajectory-based on-the-fly (surface hopping) dynamics. Our work has been the first realization of internally contracted CASPT2 nuclear gradients since CASPT2 was developed in 1992. Using our code, such dynamics simulations are now routine on parallel computers for molecules with 50 atoms and active spaces up to CAS(12,12) in the gas phase and condensed phases.