A variational approach to London dispersion interactions without density distortion

Abstract

We introduce a class of variational wavefunctions that capture the long-range interaction between neutral systems (atoms and molecules) without changing the diagonal of the density matrix of each monomer. The corresponding energy optimization yields explicit expressions for the dispersion coefficients in terms of the ground-state pair densities of the isolated systems, providing a clean theoretical framework to build new approximations in several contexts. As the individual monomer densities are kept fixed, we can also unambiguously assess the effect of the density distortion on van der Waals interactions: for example, we obtain virtually exact dispersion coefficients between two hydrogen atoms up to $C_{10}$, and relative errors below $0.2\%$ in other simple cases.

arXiv comment5 pages, plus 6 pages of supplemental material

References in corpus (4)

• Nonlocal van der Waals density functional: The simpler the better
• Variational calculations of dispersion coefficients for interactions between H, He, and Li atoms
• Dispersion interactions from a local polarizability model
• Energy Density Functionals From the Strong-Coupling Limit Applied to the Anions of the He Isoelectronic Series

Cited by in corpus (3)

• 1-matrix functional for long-range interaction energy of two hydrogen atoms
• London dispersion forces without density distortion: a path to first principles inclusion in density functional theory
• Kinetic correlation functionals from the entropic regularisation of the strictly-correlated electrons problem