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.