A Unified AMBER-Compatible Molecular Mechanics Force Field for Thiolate-Protected Gold Nanoclusters

We present transferable AMBER-compatible
force field parameters
for thiolate-protected gold nanoclusters. Five different sized clusters
containing both organo-soluble and water-soluble thiolate ligands
served as test systems in MD simulations, and parameters were validated
against DFT and experimental results. The cluster geometries remain
intact during the MD simulations in various solvents, and structural
fluctuations and energetics showed agreement with DFT calculations.
Experimental diffusion coefficients and crystal structures were also
reproduced with sufficient accuracy. The presented parameter set contains
the minimum number of cluster-specific parameters enabling the use
of these parameters for several different gold nanoclusters. The parameterization
of ligands can also be extended to different types of ligands.

本研究提出了可适配AMBER力场的可迁移力场参数，用于硫醇保护的金纳米团簇。本研究选取五种不同尺寸的团簇作为分子动力学（Molecular Dynamics, MD）模拟的测试体系，这些团簇同时包含有机可溶性与水溶性硫醇配体；参数通过与密度泛函理论（Density Functional Theory, DFT）计算结果及实验数据比对完成验证。在多种溶剂的MD模拟过程中，团簇的几何结构保持完整，其结构涨落与能量学特征均与DFT计算结果相符。实验测得的扩散系数与晶体结构也以足够的精度得到复现。本次提出的参数集仅包含最少数量的团簇专属参数，可适用于多种不同的金纳米团簇；配体的参数化方案同样可拓展至其他类型的配体。