Dispersion without Many-Body Density Distortion: Assessment on Atoms and Small Molecules.

ABSTRACT: The "fixed diagonal matrices" (FDM) dispersion formalism [Kooi, D. P.; et al. J. Phys. Chem. Lett. 2019, 10, 1537] is based on a supramolecular wave function constrained to leave the diagonal of the many-body density matrix of each monomer unchanged, reducing dispersion to a balance between kinetic energy and monomer-monomer interaction. The corresponding variational optimization leads to expressions for the dispersion energy in terms of the ground-state pair densities of the isolated monomers only, providing a framework to build new approximations without the need for polarizabilities or virtual orbitals. Despite the underlying microscopic real space mechanism being incorrect, as in the exact case there is density relaxation, the formalism has been shown to give extremely accurate

SUBMITTER: Kooi DP 

PROVIDER: S-EPMC8047766 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature