Department of Mathematics, Duke University, P.O. Box 90320, Durham, North Carolina 27708, USA.
J Chem Phys. 2017 Apr 21;146(15):154110. doi: 10.1063/1.4981021.
In this work, a novel ring polymer representation for a multi-level quantum system is proposed for thermal average calculations. The proposed representation keeps the discreteness of the electronic states: besides position and momentum, each bead in the ring polymer is also characterized by a surface index indicating the electronic energy surface. A path integral molecular dynamics with surface hopping (PIMD-SH) dynamics is also developed to sample the equilibrium distribution of the ring polymer configurational space. The PIMD-SH sampling method is validated theoretically and by numerical examples.
在这项工作中，提出了一种新的多能级量子系统的环聚合物表示方法，用于热平均计算。所提出的表示方法保持了电子态的离散性：除了位置和动量外，环聚合物中的每个珠还具有表示电子能面的表面指数。还开发了具有表面跳跃（PIMD-SH）动力学的路径积分分子动力学（PIMD-SH）动力学，以对环聚合物构象空间的平衡分布进行采样。通过理论和数值示例验证了 PIMD-SH 采样方法的有效性。
