GFN2-xTB-An Accurate and Broadly Parametrized Self-Consistent Tight-Binding Quantum Chemical Method with Multipole Electrostatics and Density-Dependent Dispersion Contributions
GFN2-xTB-An Accurate and Broadly Parametrized Self-Consistent Tight-Binding Quantum Chemical Method with Multipole Electrostatics and Density-Dependent Dispersion Contributions
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DOI：
10.1021/acs.jctc.8b01176
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发表时间：
2019-03-01
影响因子：
5.5
通讯作者：
Grimme, Stefan
中科院分区：
文献类型：
--
作者：
Bannwarth, Christoph;Ehlert, Sebastian;Grimme, Stefan
本文提出了一个扩展的半经验紧束缚模型，它主要用于快速计算大约1000个原子的分子体系的结构和非共价相互作用能。在这个所谓的GFN 2-xTB方法的本质新奇是通过累积原子多极矩的短程阻尼相互作用的各向异性二阶密度波动效应的列入。在计算需求没有明显增加的情况下，这导致了一种经验较少且总体上物理上更合理的方法，该方法不需要任何经典的卤素或氢键校正，并且仅依赖于全局和元素特定的参数（可用于氡，Z = 86）。此外，原子部分电荷相关的D4伦敦色散模型自洽地纳入，这可以自然地得到一个紧束缚图片从二阶密度起伏。完全解析和数值精确的梯度（核力）的实施。该方法的准确性基准为各种各样的系统，并与其他半经验的方法相比。沿着“目标”性质的优异性能，我们还发现“脱靶”性质，如势垒高度和分子偶极矩的较低误差。与其前体GFN-xTB相比，高计算效率沿着改进的物理特性使得该方法非常适合探索分子系统的构象空间。此外，还观察到各种基准集的显着改进，这些基准集是水溶液中生物分子系统的原型。
An extended semiempirical tight-binding model is presented, which is primarily designed for the fast calculation of structures and noncovalent interaction energies for molecular systems with roughly 1000 atoms. The essential novelty in this so-called GFN2-xTB method is the inclusion of anisotropic second order density fluctuation effects via short-range damped interactions of cumulative atomic multipole moments. Without noticeable increase in the computational demands, this results in a less empirical and overall more physically sound method, which does not require any classical halogen or hydrogen bonding corrections and which relies solely on global and element-specific parameters (available up to radon, Z = 86). Moreover, the atomic partial charge dependent D4 London dispersion model is incorporated self-consistently, which can be naturally obtained in a tight-binding picture from second order density fluctuations. Fully analytical and numerically precise gradients (nuclear forces) are implemented. The accuracy of the method is benchmarked for a wide variety of systems and compared with other semiempirical methods. Along with excellent performance for the "target" properties, we also find lower errors for "off-target" properties such as barrier heights and molecular dipole moments. High computational efficiency along with the improved physics compared to its precursor GFN-xTB makes this method well-suited to explore the conformational space of molecular systems. Significant improvements are furthermore observed for various benchmark sets, which are prototypical for biomolecular systems in aqueous solution.