A black-box type procedure is presented for the generation of a molecule-specific, intermolecular potential energy function. The method uses quantum chemical (QC) information from our recently published extended tight-binding semi-empirical scheme (GFN-xTB) and can treat non-covalently bound complexes and aggregates with almost arbitrary chemical structure. The necessary QC information consists of the equilibrium structure, Mulliken atomic charges, charge centers of localized molecular orbitals, and also of frontier orbitals and orbital energies. The molecular pair potential includes model density dependent Pauli repulsion, penetration, as well as point charge electrostatics, the newly developed D4 dispersion energy model, Drude oscillators for polarization, and a charge-transfer term. Only one element-specific and about 20 global empirical parameters are needed to cover systems with nuclear charges up to radon (Z = 86). The method is tested for standard small molecule interaction energy benchmark sets where it provides accurate intermolecular energies and equilibrium distances. Examples for structures with a few hundred atoms including charged systems demonstrate the versatility of the approach. The method is implemented in a stand-alone computer code which enables rigid-body, global minimum energy searches for molecular aggregation or alignment.

中文翻译：

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基于紧密结合量子化学计算的一般分子间力场

提出了一种黑盒型程序，用于产生分子特异性的分子间势能函数。该方法使用了来自我们最近发布的扩展紧密结合半经验方案（GFN-xTB）的量子化学（QC）信息，可以处理具有几乎任意化学结构的非共价结合的复合物和聚集体。必要的QC信息包括平衡结构，Mulliken原子电荷，局部分子轨道的电荷中心以及边界轨道和轨道能量。分子对电势包括模型密度相关的Pauli排斥力，渗透力以及点电荷静电，新开发的D4色散能量模型，极化的Drude振荡器以及电荷转移项。Z = 86）。该方法已经过标准小分子相互作用能基准测试，并提供了准确的分子间能和平衡距离。具有数百个原子的结构（包括带电系统）的示例证明了该方法的多功能性。该方法在独立的计算机代码中实现，该代码可进行刚体全局全局最小能量搜索以进行分子聚集或对齐。