Electron-nucleus correlation functional for multicomponent density-functional theory

An electron-nucleus Colle-Salvetti-type correlation functional for multicomponent density-functional theory is proposed. We demonstrate that our correlation functional quantitatively reproduces the quantum mechanical effects of protons; the mean absolute deviation value is 2.8 millihartrees for the optimized structures of hydrogen-containing molecules, and the effective potential energy curve of the hydrogen molecule is well reproduced. Since this functional is derived without any unphysical assumption, the strategy taken in this development will be a promising recipe to make new functionals for the potentials of other particles' interactions, such as electron-positron and electron-muon.