理论模拟含氢键二次有机气溶胶的振动光谱

Secondary organic aerosols are formed in the atmosphere through condensation of oxidation products of volatile organic compounds. Secondary organic aerosols, as an important part of atmospheric aerosol, have great effects on the climate change，environmental pollution and human health, and have been given great attention from research scientists. Spectroscopic characterization of secondary organic aerosols is an important experimental route to investigate their components, architecture, size, shape and other intrinsic particle properties. However, due to the intrinsic complexes of the secondary organic aerosols, the observed experimental spectra are very difficult to be assigned. Most of the secondary organic aerosols have hydrogen bonds, which are easy to form dynamic hydrogen-bond network during their condensation, and have non-negligible nuclear quantum effects. For this research, based on the hot topic of atmospheric chemistry, secondary organic aerosols with hydrogen bonds are selected as our research objects. A path-integral molecular dynamics (PIMD) code will be developed in this project. With our own ab initio-based representation of the underlying inter- and intra- molecular interactions and forces, it will be applied in simulating the structure and dynamics of hydrogen-bond network formed in second organic aerosols to investigate the quantum effects with temperature dependent. Combining with first perturbation theory and central molecular dynamics method, PIMD will also be used in simulating the vibrational spectra of the secondary organic aerosol, and help experimentalists to assign their observations, and in addition to provide the basic data for future analyzing the satellite remote spectroscopic information.

二次有机气溶胶通过凝聚大气中挥发性有机化合物的氧化产物而形成。二次有机气溶胶作为气溶胶的重要组成部分，对气候改变、环境污染、人类健康有很大影响， 备受研究者关注。 二次有机气溶胶的光谱表征是实验研究其成份、结构、大小、形状等内部性质的重要手段。 而由于其内在的复杂性, 给实验科学家的光谱指认造成了巨大的困难。 二次有机气溶胶中常含有大量氢键, 凝聚中容易形成动态氢键网络，具有不可忽视的量子效应。 本项目立足大气化学热点， 以含氢键二次有机气溶胶为研究对象，拟发展量子路径积分分子动力学（PIMD)程序， 应用自己发展的从头算基础的分子内－分子间相关势和力场， 模拟二次有机气溶胶的内部结构和氢键动力学，考察温度相关的量子效应。 结合一次微扰理论和中心分子动力学方法（CMD）， 该项目拟模拟二次有机气溶胶的振动光谱，帮助实验化学家进行光谱指认，为进一步解析卫星遥感光谱信息提供基础数据。

二次有机气溶胶通过凝聚大气中挥发性有机化合物的氧化产物而形成。 二次有机气溶胶作为气溶胶的重要组成部分， 对气候改变、环境污染、人类健康有很大影响， 备受研究者关注。 二次有机气溶胶的光谱表征是实验研究其组成、结构、大小、形状等内部性质的重要手段。 而由于其内在的复杂性, 给实验科学家的光谱指认造成了巨大的困难。 二次有机气溶胶中常含有大量氢键, 凝聚中容易形成动态氢键网络，具有不可忽视的量子效应。 本项目立足大气化学热点， 以含氢键二次有机气溶胶为研究对象，发展了量子振动微扰方法和刚性转子路径积分分子动力学程序，应用自己发展的分子内振动激发的分子间模型势（MD-MLR)，或直接的QM/MM从头算势能，模拟了生色分子在量子或经典团簇中的红外光谱，考察温度相关的量子效应，分析了团簇的内部结构和氢键动力学，阐明了分子内－分子间耦合的本源，为进一步研究更大、更复杂体系的约化维度处理方法奠定了重要的理论基础。