Fast and Accurate Electrostatics in Metal Organic Frameworks with a Robust Charge Equilibration Parameterization for High-Throughput Virtual Screening of Gas Adsorption

The
charge equilibration (QEq) method has been parametrized to
reproduce the ab-initio-derived electrostatic potential in a large
and diverse training set of 543 metal organic frameworks (MOFs) containing
the most popular Zn, Cu, and V structural building units (SBUs), 52
different organic carboxylate- and nitrogen-capped SBUs, and the 17
functional groups. The MOF electrostatic-potential-optimized charge
scheme, or MEPO-QEq, was validated by evaluating the CO2 uptake and heats of adsorption in the 543 member training set and
a nonoverlapping 693 member validation set. Compared with the results
obtained from ab-initio-derived charges, the MEPO-QEq charges give
Pearson (linear) and Spearman (rank-order) correlation coefficients
of >0.97 for these two sets. MEPO-QEq enables near-ab-initio quality
nonbonded electrostatic interactions to be evaluated using the fast
QEq method for fast and accurate virtual high-throughput screening
of gas-adsorption properties in MOFs.

电荷平衡（charge equilibration, QEq）方法已完成参数化，可在包含最常见锌（Zn）、铜（Cu）与钒（V）结构构筑单元（structural building units, SBUs）、52种不同有机羧酸封端及氮封端结构构筑单元，以及17种官能团的543个金属有机框架（metal organic frameworks, MOFs）组成的大型多样化训练集中，复现从头算（ab-initio）所得的静电势。本研究提出的经金属有机框架静电势优化的电荷方案（MEPO-QEq），通过在上述543个成员的训练集与不重叠的693个成员的验证集中评估二氧化碳（CO₂）吸附量及吸附热完成验证。与从头算电荷得到的结果相比，MEPO-QEq电荷在这两个数据集上的皮尔逊（线性）相关系数与斯皮尔曼（秩相关）相关系数均大于0.97。MEPO-QEq可借助快速QEq方法计算达到从头算精度的非键合静电相互作用，从而实现对金属有机框架中气体吸附性质的快速精准虚拟高通量筛选。