Albaugh Alex, Head-Gordon Teresa, Niklasson Anders M N
Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
J Chem Theory Comput. 2018 Feb 13;14(2):499-511. doi: 10.1021/acs.jctc.7b01041. Epub 2018 Jan 31.
Generalized extended Lagrangian Born-Oppenheimer molecular dynamics (XLBOMD) methods provide a framework for fast iteration-free simulations of models that normally require expensive electronic ground state optimizations prior to the force evaluations at every time step. XLBOMD uses dynamically driven auxiliary degrees of freedom that fluctuate about a variationally optimized ground state of an approximate "shadow" potential which approximates the true reference potential. While the requirements for such shadow potentials are well understood, constructing such potentials in practice has previously been ad hoc, and in this work, we present a systematic development of XLBOMD shadow potentials that match the reference potential to any order. We also introduce a framework for combining friction-like dissipation for the auxiliary degrees of freedom with general-order integration, a combination that was not previously possible. These developments are demonstrated with a simple fluctuating charge model and point induced dipole polarization models.
广义扩展拉格朗日玻恩-奥本海默分子动力学（XLBOMD）方法为快速无迭代模拟提供了一个框架，这类模拟通常需要在每个时间步进行力评估之前进行昂贵的电子基态优化。XLBOMD使用动态驱动的辅助自由度，这些自由度围绕一个近似“影子”势的变分优化基态波动，该“影子”势近似真实的参考势。虽然对这种影子势的要求已被充分理解，但在实践中构建这种势以前是临时的，在这项工作中，我们提出了XLBOMD影子势的系统开发方法，使其与参考势在任何阶数上匹配。我们还引入了一个框架，将辅助自由度的类摩擦耗散与任意阶积分相结合，这种结合以前是不可能的。通过一个简单的波动电荷模型和点感应偶极极化模型对这些进展进行了演示。
