气体在纳孔分子材料中吸附的多尺度理论模拟

项目名称： 气体在纳孔分子材料中吸附的多尺度理论模拟

项目编号： No.21303011

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 李文亮

作者单位： 东北师范大学

项目金额： 25万元

中文摘要： 针对目前理论模拟气体在多孔材料中吸附的准确性预测问题，以纳孔分子材料吸附气体为研究对象，提出一套不依赖经验参数的高精度模拟方案。采用色散校正双杂化密度泛函方法(DHDF-D3）准确描述该吸附体系的弱相互作用势能曲线，并通过专门描述非共价相互作用的高精度力场vdW3拟合DHDF-D3相互作用能。最后通过该力场解析能量进行巨正则蒙特卡洛(GCMC)模拟，得到准确的吸附等温线、吸附热、气体分布密度、构象等信息。针对高精度方案无法对大量材料进行模拟的问题，设计一套具有可迁移力场参数的高效率模拟方案。方案中使用色散校正密度泛函（DFT-D3）拟合常规力场（包括LJ、Morse、MMSV、Buck-CK等），得到各类原子或官能团的力场参数。在设计新材料过程中，使用高效率模拟方案初选，再经高精度模拟方案确实，可快速、准确筛选出具有特定吸附能力的纳孔分子材料。

中文关键词： 多尺度模拟；纳孔分子材料；高效率；高精度；气体吸附

英文摘要： A general high-accuracy simulation procedure is proposed with the aim to accurate prediction of the gas uptakes in porous materials by taking the adsorption of gases in nanoporous molecular materials as an example. The double hybrid density functional theory combining dispertion correction method (DHDF-D3) is to be used to produce reference data for fitting a force field vdW3, which is appliable in grand-canonical Monte Carlo (GCMC) simulations. Adsorption isotherms, heats of adsorption, spatial distribution, and orientations of gases could be observed subsequently. Because high-accuracy procedure with high-level calculations is hardly able to simulate very large amounts of materials, a multiscal simulation procedure on the basis of transferable force field parameters with high efficiency is proposed to perform large scale calculations. In this procedure, DFT-D3 is to be used to fit the normal force field, like LJ, Morse, MMSV, and Buck-CK. By combining the high-accuracy and high-efficiency simulation procedures, the porous materials with specific adsorption capacity can be accurately and efficiently screened from the abundant materials.

英文关键词： multiscale simulation；nanoporous molecular materials；efficiency；;accuracy；gas adsorption