Development of an empirical force field for silica. Application to the quartz-water interface
Development of an empirical force field for silica. Application to the quartz-water interface
复制标题
DOI：
10.1021/jp055341j
复制
发表时间：
2006-02-16
影响因子：
3.3
通讯作者：
MacKerell, AD
中科院分区：
文献类型：
--
作者：
Lopes, PEM;Murashov, V;MacKerell, AD
粉状结晶二氧化硅与包括肺部在内的生物系统相互作用，会导致细胞损伤、炎症和细胞凋亡。为了能够对这些致病过程进行计算原子模拟，包括二氧化硅表面与生物分子之间的相互作用，开发了与CHARMM经验力场兼容的新的石英参数。对参数进行了优化，以再现cc-石英的实验几何形状、从头算振动光谱以及模型化合物与水的相互作用。用新发展的力场研究了水与cc-石英两个奇异表面(011)和(100)的相互作用。监测和分析的性质包括水分子在垂直于表面的平面内的密度变化，水的氢键网络在吸附时的破坏，以及水中氧原子在Van Hove自关联函数下的时空关联。计算了受限空间中水的态谱的振动密度，并与中子散射实验结果进行了比较。该模型清楚地再现了禁闭时受阻平移峰的衰减和向更高频率的移动。然而，在目前的经验水平下，模型限制条件下的振动峰上移仍然没有得到充分的代表。
Interactions of pulverized crystalline silica with biological systems, including the lungs, cause cell damage, inflammation, and apoptosis. To allow computational atomistic modeling of these pathogenic processes, including interactions between silica surfaces and biological molecules, new parameters for quartz, compatible with the CHARMM empirical force field were developed. Parameters were optimized to reproduce the experimental geometry of cc-quartz, ab initio vibrational spectra, and interactions between model compounds and water. The newly developed force field was used to study interactions of water with two singular surfaces of cc-quartz, (011) and (100). Properties monitored and analyzed include the variation of the density of water molecules in the plane perpendicular to the surface, disruption of the water H-bond network upon adsorption, and space-time correlations of water oxygen atoms in terms of Van Hove self-correlation functions. The vibrational density of states spectra of water in confined compartments were also computed and compared with experimental neutron-scattering results. Both the attenuation and shifting to higher frequencies of the hindered translational peaks upon confinement are clearly reproduced by the model. However, an upshift of librational peaks under the conditions of model confinement still remains underrepresented at the current empirical level.