A Density Functional Approach to Para-hydrogen at Zero Temperature

Abstract

We have developed a density functional (DF) built so as to reproduce either the metastable liquid or the solid equation of state of bulk para-hydrogen, as derived from quantum Monte Carlo zero temperature calculations. As an application, we have used it to study the structure and energetics of small para-hydrogen clusters made of up to N = 40 molecules. We compare our results for liquid clusters with diffusion Monte Carlo (DMC) calculations and find a fair agreement between them. In particular, the transition found within DMC between hollow-core structures for small N values and center-filled structures at higher N values is reproduced. The present DF approach yields results for (pH 2 ) N clusters indicating that for small N values a liquid-like character of the clusters prevails, while solid-like clusters are instead energetically favored for N ≥ 15.

Density functional theory of doped superfluid liquid helium and nanodroplets

“…Refs.56 and 57 and references therein. Finally, we note that a method similar to the one used for superfluid4 He has also been used to describe cold dipolar Bose gases 58 and para-hydrogen clusters, for which a DFT-based approach is also available 59.…”