Bjorgaard J A, Sheppard D, Tretiak S, Niklasson A M N
Computational Physics Division, ‡Theoretical Division, ¶Center for Integrated Nanotechnologies, and §Center for Nonlinear Studies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
J Chem Theory Comput. 2018 Feb 13;14(2):799-806. doi: 10.1021/acs.jctc.7b00857. Epub 2018 Jan 31.
An extended Lagrangian framework for excited state molecular dynamics (XL-ESMD) using time-dependent self-consistent field theory is proposed. The formulation is a generalization of the extended Lagrangian formulations for ground state Born-Oppenheimer molecular dynamics [Phys. Rev. Lett. 2008 100, 123004]. The theory is implemented, demonstrated, and evaluated using a time-dependent semiempirical model, though it should be generally applicable to ab initio theory. The simulations show enhanced energy stability and a significantly reduced computational cost associated with the iterative solutions of both the ground state and the electronically excited states. Relaxed convergence criteria can therefore be used both for the self-consistent ground state optimization and for the iterative subspace diagonalization of the random phase approximation matrix used to calculate the excited state transitions. The XL-ESMD approach is expected to enable numerically efficient excited state molecular dynamics for such methods as time-dependent Hartree-Fock (TD-HF), Configuration Interactions Singles (CIS), and time-dependent density functional theory (TD-DFT).
提出了一种基于含时自洽场理论的激发态分子动力学扩展拉格朗日框架（XL - ESMD）。该公式是基态玻恩 - 奥本海默分子动力学扩展拉格朗日公式的推广[《物理评论快报》2008年第100卷，123004]。尽管该理论通常应适用于从头算理论，但本文使用含时半经验模型进行了实现、演示和评估。模拟结果表明，与基态和电子激发态的迭代求解相关的能量稳定性增强，计算成本显著降低。因此，对于自洽基态优化以及用于计算激发态跃迁的随机相位近似矩阵的迭代子空间对角化，都可以使用放宽的收敛标准。预计XL - ESMD方法将为诸如含时哈特里 - 福克（TD - HF）、单组态相互作用（CIS）和含时密度泛函理论（TD - DFT）等方法实现数值高效的激发态分子动力学。
