Partition Analysis for Density-Functional Tight-Binding

J Phys Chem A. 2020 Dec 10;124(49):10346-10358. doi: 10.1021/acs.jpca.0c08204. Epub 2020 Nov 12.

Abstract

High-order charge transfer is incorporated into the fragment molecular orbital (FMO) method using a charge transfer state with fractional charges. This state is used for a partition analysis of properties based on segments that may be different from fragments in FMO. The partition analysis is also formulated for calculations without fragmentation. All development in this work is limited to density-functional tight-binding. The analysis is applied to a water cluster, crambin (PDB: 1CBN), and two complexes of Trp-cage (1L2Y) with ligands. The contributions of functional groups in ligands are obtained, providing useful information for drug discovery.