title: Development of semiclassical molecular dynamics simulation method.
abstract: Various quantum mechanical effects such as nonadiabatic transitions, quantum mechanical tunneling and coherence play crucial roles in a variety of chemical and biological systems. In this paper, we propose a method to incorporate tunneling effects into the molecular dynamics (MD) method, which is purely based on classical mechanics. Caustics, which define the boundary between classically allowed and forbidden regions, are detected along classical trajectories and the optimal tunneling path with minimum action is determined by starting from each appropriate caustic. The real phase associated with tunneling can also be estimated. Numerical demonstration with use of a simple collinear chemical reaction O + HCl → OH + Cl is presented in order to help the reader to well comprehend the method proposed here. Generalization to the on-the-fly ab initio version is rather straightforward. By treating the nonadiabatic transitions at conical intersections by the Zhu-Nakamura theory, new semiclassical MD methods can be developed.
authors.affiliation: Institute of Molecular Science, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu, 30010 Taiwan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Department of Materials and Life Science, Sophia University, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan. shinkoh.nanbu@sophia.ac.jp o-ta.com@eagle.sophia.ac.jp.
authors.forename: Shinkoh
authors.initials: S
authors.lastname: Nanbu
authors.affiliation: Institute of Physics, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu, 30010 Taiwan. tera@mail.nctu.edu.tw.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Teranishi
authors.affiliation: Department of Materials and Life Science, Sophia University, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan. shinkoh.nanbu@sophia.ac.jp o-ta.com@eagle.sophia.ac.jp.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Ohta