Effective force fields for condensed phase systems from ab initio molecular dynamics simulation:: A new method for force-matching
Effective force fields for condensed phase systems from ab initio molecular dynamics simulation:: A new method for force-matching
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DOI：
10.1063/1.1739396
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发表时间：
2004-06-15
影响因子：
4.4
通讯作者：
Voth, GA
中科院分区：
文献类型：
--
作者：
Izvekov, S;Parrinello, M;Voth, GA
提出了一种新的最小二乘拟合方法，用于从从头算产生的轨迹和力数据库中获得经典力场（例如，Car-Parrinello）分子动力学（MD）模拟。该方法被施加到推导出有效的nonpolarizable三站点力场的液态水在环境条件下从Car-Parrinello MD模拟在Becke-Lee-Yang-Parr近似的电子密度泛函理论。力匹配过程包括短程非键合力、键合力和原子部分电荷的拟合。水力场的各种参数化的不同之处在于施加到短程相互作用项的强制平滑截止。这些是通过拟合的轨迹和力的数据产生的Car-Parrinello MD模拟系统的32和64水分子。新的水力场是假设柔性或刚性分子几何形状而开发的。使用拟合力场模拟的液态水的结构和自扩散性质与在基础Car-Parrinello MD模拟中观察到的那些密切一致。由此产生的经验模型相比，实验比许多传统的简单点电荷（SPC）模型。拟合势也显示出与更复杂的分子内势联合收割机很好地结合。重要的是，新模型的计算成本与SPC类电位相当。(C)2004年，美国物理学会。
A novel least-squares fitting approach is presented to obtain classical force fields from trajectory and force databases produced by ab initio (e.g., Car-Parrinello) molecular dynamics (MD) simulations. The method was applied to derive effective nonpolarizable three-site force fields for liquid water at ambient conditions from Car-Parrinello MD simulations in the Becke-Lee-Yang-Parr approximation to the electronic density functional theory. The force-matching procedure includes a fit of short-ranged nonbonded forces, bonded forces, and atomic partial charges. The various parameterizations of the water force field differ by an enforced smooth cut-off applied to the short-ranged interaction term. These were obtained by fitting to the trajectory and force data produced by Car-Parrinello MD simulations of systems of 32 and 64 H2O molecules. The new water force fields were developed assuming both flexible or rigid molecular geometry. The simulated structural and self-diffusion properties of liquid water using the fitted force fields are in close agreement with those observed in the underlying Car-Parrinello MD simulations. The resulting empirical models compare to experiment much better than many conventional simple point charge (SPC) models. The fitted potential is also shown to combine well with more sophisticated intramolecular potentials. Importantly, the computational cost of the new models is comparable to that for SPC-like potentials. (C) 2004 American Institute of Physics.