论文标题
基于密度 - 矩阵的扩展Lagrangian Born-Oppenheimer分子动力学
Density-matrix based Extended Lagrangian Born-Oppenheimer Molecular Dynamics
论文作者
论文摘要
扩展的Lagrangian Born-Oppenheimer分子动力学[{\ em Phys。\ rev。\ lett。\ \} {\ bf 2008}，{\ em 100}，123004]为Hartree-fock理论提出，在其中，自由度以free tiver的速度代表了fred forcations，其中包括frefortions free cortion cortion firaction firctions。与常规的直接邻苯二摄分子动力学模拟相反，在力评估之前，不需要迭代性自洽场优化。对于差异较小或消失的势能景观的样品区域，这会导致常规直接启动的分子动力学模拟中的特定收敛问题，提出了扩展电子自由度的自适应整合方案。 The integration scheme is based on a tunable, low-rank approximation of a fourth-order kernel, ${\cal K}$, that determines the metric tensor, ${\cal T}\equiv {\cal K}^T{\cal K}$, used in the extended harmonic oscillator of the Lagrangian that generates the dynamics of the electronic degrees of freedom.该公式和算法提供了使用密度矩阵形式主义的量子化学，密度功能理论和半经验方法的量子化学，密度功能理论和半经验方法的一般指南。
Extended Lagrangian Born-Oppenheimer molecular dynamics [{\em Phys.\ Rev.\ Lett.\ } {\bf 2008}, {\em 100}, 123004] is presented for Hartree-Fock theory, where the extended electronic degrees of freedom are represented by a density matrix, including fractional occupation numbers at elevated electronic temperatures. In contrast to regular direct Born-Oppenheimer molecular dynamics simulations, no iterative self-consistent field optimization is required prior to the force evaluations. To sample regions of the potential energy landscape where the gap is small or vanishing, which leads to particular convergence problems in regular direct Born-Oppenheimer molecular dynamics simulations, an adaptive integration scheme for the extended electronic degrees of freedom is presented. The integration scheme is based on a tunable, low-rank approximation of a fourth-order kernel, ${\cal K}$, that determines the metric tensor, ${\cal T}\equiv {\cal K}^T{\cal K}$, used in the extended harmonic oscillator of the Lagrangian that generates the dynamics of the electronic degrees of freedom. The formulation and algorithms provide a general guide to implement extended Lagrangian Born-Oppenheimer molecular dynamics for quantum chemistry, density functional theory, and semiempirical methods using a density matrix formalism.
