...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >S/G-1: An ab Initio Force-Field Blending Frozen Hermite Gaussian Densities and Distributed Multipoles. Proof of Concept and First Applications to Metal Cations
【24h】

S/G-1: An ab Initio Force-Field Blending Frozen Hermite Gaussian Densities and Distributed Multipoles. Proof of Concept and First Applications to Metal Cations

机译：S / G-1：从头算力场混合冻结的厄米高斯密度和分布式多极。概念验证和金属阳离子的首次应用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We demonstrate as a proof of principle the capabilities of a novel hybrid MM′/MM polarizable force field to integrate short-range quantum effects in molecular mechanics (MM) through the use of Gaussian electrostatics. This lead to a further gain in accuracy in the representation of the first coordination shell of metal ions. It uses advanced electrostatics and couples two point dipole polarizable force fields, namely, the Gaussian electrostatic model (GEM), a model based on density fitting, which uses fitted electronic densities to evaluate nonbonded interactions, and SIBFA (sum of interactions between fragments ab initio computed), which resorts to distributed multipoles. To understand the benefits of the use of Gaussian electrostatics, we evaluate first the accuracy of GEM, which is a pure density-based Gaussian electrostatics model on a test Ca(II)?H_2O complex. GEM is shown to further improve the agreement of MM polarization with ab initio reference results. Indeed, GEM introduces nonclassical effects by modeling the short-range quantum behavior of electric fields and therefore enables a straightforward (and selective) inclusion of the sole overlap-dependent exchange-polarization repulsive contribution by means of a Gaussian damping function acting on the GEM fields. The S/G-1 scheme is then introduced. Upon limiting the use of Gaussian electrostatics to metal centers only, it is shown to be able to capture the dominant quantum effects at play on the metal coordination sphere. S/G-1 is able to accurately reproduce ab initio total interaction energies within closed-shell metal complexes regarding each individual contribution including the separate contributions of induction, polarization, and charge-transfer. Applications of the method are provided for various systems including the HIV-1 NCp7-Zn(II) metalloprotein. S/G-1 is then extended to heavy metal complexes. Tested on Hg(II) water complexes, S/G-1 is shown to accurately model polarization up to quadrupolar response level. This opens up the possibility of embodying explicit scalar relativistic effects in molecular mechanics thanks to the direct transferability of ab initio pseudopotentials. Therefore, incorporating GEM-like electron density for a metal cation enable the introduction of nonambiguous short-range quantum effects within any point-dipole based polarizable force field without the need of an extensive parametrization.
机译：作为原理的证明，我们证明了一种新颖的混合MM'/ MM可极化力场通过使用高斯静电学将短程量子效应整合到分子力学（MM）中的功能。这导致金属离子的第一配位壳的表示的准确性进一步提高。它使用先进的静电并耦合两点偶极极化力场，即高斯静电模型（GEM），这是一种基于密度拟合的模型，该模型使用拟合的电子密度来评估非键合相互作用，而SIBFA（片段之间的相互作用从头算起）计算得出的），它诉诸于分布式多极点。为了了解使用高斯静电的好处，我们首先评估GEM的准确性，GEM是在测试Ca（II）？H_2O配合物上基于纯密度的高斯静电模型。实验表明，GEM可从头算参考结果进一步改善MM极化的一致性。确实，GEM通过对电场的短距离量子行为进行建模而引入了非经典效应，因此，通过作用于GEM场上的高斯阻尼函数，可以直接（选择性地）包含唯一的依赖于重叠的交换-极化排斥作用。 。然后介绍S / G-1方案。仅将高斯静电的使用限制在金属中心时，它就能够捕获金属配位球上起作用的主要量子效应。 S / G-1能够准确地重现封闭壳金属络合物中从头开始的总相互作用能，涉及到每个单独的贡献，包括感应，极化和电荷转移的单独贡献。该方法的应用可用于包括HIV-1 NCp7-Zn（II）金属蛋白在内的各种系统。然后将S / G-1扩展到重金属络合物。在Hg（II）水络合物上进行测试，显示S / G-1可以准确地模拟高达四极响应水平的极化。由于从头算起准电势的直接可传递性，这开辟了在分子力学中体现明确的标量相对论效应的可能性。因此，将类似GEM的电子密度结合到金属阳离子中，可以在任何基于点偶极子的可极化力场内引入明确的短程量子效应，而无需进行广泛的参数化。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号