Partition potential for hydrogen-bonding in formic acid dimers

TL;DR

This study uses Partition Density Functional Theory to analyze hydrogen bonding in formic acid dimers, revealing the non-transferable nature of the partition potential and the relationship between deformation energies and binding strength.

Contribution

It provides new insights into the behavior of the partition potential and deformation energies in hydrogen-bonded dimers, highlighting their global and cooperative characteristics.

Findings

Partition potential shows no transferable features in bonding regions.

Fragment deformation energies increase with larger binding energies.

Deformation patterns are similar across different hydrogen bonds.

Abstract

The ground-state energy and density of four low-energy conformations of the formic acid dimer were calculated via Partition Density Functional Theory (PDFT). The differences between isolated and PDFT monomer densities display similar deformation patterns for primary and secondary hydrogen bonds among all four dimers. In contrast, the partition potential shows no transferable features in the bonding regions. These observations highlight the global character of the partition potential and the cooperative effect that occurs when a dimer is bound via more than one hydrogen bond. We also provide numerical confirmation of the intuitive (but unproven) observation that fragment deformation energies are larger for systems with larger binding energies.