- #1

Spathi

- 77

- 7

- TL;DR Summary
- I’d like to ask both physicist and physical chemists, whether the dispersion interaction is a kind of Casimir effect (as I heard).

When quantum chemistry computations are performed, different methods are used. Among the most popular are the density functional theory (DFT) methods. And it is known that the DFT approach usually underestimates the dispersion interaction, and to solve this problem, often empirical dispersion corrections are used (e.g. Grimme’s D3). I have also heard that the Møller–Plesset perturbation theory methods (more exactly, a PT addition to the Hartree-Fock method) like MP2 usually overestimate the dispersion interaction. So I’d like to ask both physicist and physical chemists, whether the dispersion interaction is a kind of Casimir effect (as I heard). Also I have a question, is that correct that the dispersion interaction means only the attraction between fragments of molecules; and maybe this is related to a strange form of Ramanujan summation used as a theoretical explanation of the Casimir effect (this sum is negative).