Instituto de Química Física Rocasolano, CSIC, Serrano 119, E-28006 Madrid, Spain.
J Chem Phys. 2014 Jan 14;140(2):024504. doi: 10.1063/1.4861042.
An extension of the well established Reverse Monte Carlo (RMC) method for modeling systems under close confinement has been developed. The method overcomes limitations induced by close confinement in systems such as fluids adsorbed in microporous materials. As a test of the method, we investigate a model system of (36)Ar adsorbed into two zeolites with significantly different pore sizes: Silicalite-I (a pure silica form of ZSM-5 zeolite, characterized by relatively narrow channels forming a 3D network) at partial and full loadings and siliceous Faujasite (which exhibits relatively wide channels and large cavities). The model systems are simulated using grand canonical Monte Carlo and, in each case, its structure factor is used as input for the proposed method, which shows a rapid convergence and yields an adsorbate microscopic structure in good agreement with that of the model system, even to the level of three body correlations, when these are induced by the confining media. The application to experimental systems is straightforward incorporating factors such as the experimental resolution and appropriate q-sampling, along the lines of previous experiences of RMC modeling of powder diffraction data including Bragg and diffuse scattering.
已经开发出一种扩展的成熟的反蒙特卡罗（RMC）方法，用于模拟紧密受限系统中的模型。该方法克服了在诸如微孔材料中吸附的流体等系统中由于紧密受限而产生的限制。作为方法的测试，我们研究了（36）Ar 吸附到两种具有显著不同孔径的沸石中的模型系统：Silicalite-I（ZSM-5 沸石的纯硅形式，其特征是相对较窄的通道形成 3D 网络）在部分和全负载下以及硅质 Faujasite（其具有相对较宽的通道和大空腔）。使用巨正则蒙特卡罗模拟模型系统，并且在每种情况下，其结构因子都用作所提出方法的输入，该方法显示出快速收敛，并产生与模型系统非常吻合的吸附微观结构，甚至在由约束介质诱导的三体相关的情况下也是如此。该方法可直接应用于实验系统，包括实验分辨率和适当的 q 采样等因素，这与 RMC 对粉末衍射数据（包括布拉格和漫散射）建模的先前经验一致。
