Efficient algorithm based on monte carlo method for calculation of gas adsorption of metal organic frameworks

Abstract

Porous materials are promising materials for a wide range of applications, especially, gas storage/separation. Computational methods are applied when identification of adsorption properties of porous materials. In this works, we suggest a judicious biased Widom insertion method that can efficiently and accurately calculate the adsorption properties of porous materials. In biased Widom insertion, we divided the total volume of porous materials into low and high potential energy regions such that the sampling of guest configurations are focused on low potential energy region. We tested our method for $CO_2$, $C_2H_2$, $CH_4$, and $N_2$ adsorption in Mg and Zn-MOF-74, which have strongly adsorbing open metal sites. We show that our method applies well to porous materials with open metal sites, which making low potential energy region narrow. In addition, we find the reversal of binding energies and the henry adsorption coefficient contrary to general trends. We expect that our method can identify the properties for many other systems and speed up the screening for a large number of porous materials.