Path-integral isomorphic Hamiltonian for including nuclear quantum effects in non-adiabatic dynamics.
Path-integral isomorphic Hamiltonian for including nuclear quantum effects in non-adiabatic dynamics.
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DOI：
10.1063/1.5005544
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发表时间：
2017-09
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影响因子：
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通讯作者：
Xuecheng Tao;Philip Shushkov;Thomas F. Miller
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文献类型：
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作者：
Xuecheng Tao;Philip Shushkov;Thomas F. Miller
我们描述了一个路径积分的方法，包括核量子效应的非绝热化学动力学模拟。对于具有多个电子能级的一般物理系统，引入了一个相应的同构哈密顿量，使得对具有经典核自由度的同构哈密顿量进行玻尔兹曼采样，得到原物理系统的精确量子玻尔兹曼分布.在一个单一的电子能级的限制，同构的哈密顿量减少到熟悉的情况下，无论是环聚合物分子动力学（RPMD）或质心分子动力学哈密顿量，这取决于实施。同构哈密顿量的一个优点是，它可以很容易地与现有的混合量子经典动力学方法，如表面跳跃或Eschlafest动力学相结合，使电子非绝热过程的模拟与核量子效应。我们提出了数值应用的同构哈密顿模型的两个和三个级别的系统，令人鼓舞的结果，包括改进后，以前报道的组合RPMD与表面跳跃在深隧穿制度。
We describe a path-integral approach for including nuclear quantum effects in non-adiabatic chemical dynamics simulations. For a general physical system with multiple electronic energy levels, a corresponding isomorphic Hamiltonian is introduced such that Boltzmann sampling of the isomorphic Hamiltonian with classical nuclear degrees of freedom yields the exact quantum Boltzmann distribution for the original physical system. In the limit of a single electronic energy level, the isomorphic Hamiltonian reduces to the familiar cases of either ring polymer molecular dynamics (RPMD) or centroid molecular dynamics Hamiltonians, depending on the implementation. An advantage of the isomorphic Hamiltonian is that it can easily be combined with existing mixed quantum-classical dynamics methods, such as surface hopping or Ehrenfest dynamics, to enable the simulation of electronically non-adiabatic processes with nuclear quantum effects. We present numerical applications of the isomorphic Hamiltonian to model two- and three-level systems, with encouraging results that include improvement upon a previously reported combination of RPMD with surface hopping in the deep-tunneling regime.