Extended Lagrangian Born-Oppenheimer molecular dynamics with dissipation
Extended Lagrangian Born-Oppenheimer molecular dynamics with dissipation
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DOI：
10.1063/1.3148075
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发表时间：
2009-06-07
影响因子：
4.4
通讯作者：
Weber, Valery
中科院分区：
文献类型：
--
作者：
Niklasson, Anders M. N.;Steneteg, Peter;Weber, Valery
时间可逆扩展拉格朗日玻恩-奥本海默分子动力学中电子自由度传播的稳定性和耗散 [Niklasson，Phys。莱特牧师。 97、123001（2006）；物理。莱特牧师。 100, 123004 (2008)]进行了分析。由于时间可逆传播，扩展电子自由度的动力学是无损的，不会消散数值误差。因此，对于“噪声”条件下的长时间仿真，数值误差可能会累积到较大的波动。我们通过引入耗散的外部电子力来解决这个问题，该电子力可以消除噪声，同时保持能量稳定。该方法对应于具有内部数值误差波动和外部近似能量守恒耗散力的电子自由度的类朗之万动力学。通过调整耗散来平衡数值波动，可以将外部扰动保持在最低限度。
Stability and dissipation in the propagation of the electronic degrees of freedom in time-reversible extended Lagrangian Born-Oppenheimer molecular dynamics [Niklasson , Phys. Rev. Lett. 97, 123001 (2006); Phys. Rev. Lett. 100, 123004 (2008)] are analyzed. Because of the time-reversible propagation the dynamics of the extended electronic degrees of freedom is lossless with no dissipation of numerical errors. For long simulation times under "noisy" conditions, numerical errors may therefore accumulate to large fluctuations. We solve this problem by including a dissipative external electronic force that removes noise while keeping the energy stable. The approach corresponds to a Langevin-like dynamics for the electronic degrees of freedom with internal numerical error fluctuations and external, approximately energy conserving, dissipative forces. By tuning the dissipation to balance the numerical fluctuations the external perturbation can be kept to a minimum.