Pair potential of liquid metallic Be from electron theory compared and contrasted with recent ab initio work on the free-space beryllium dimer

Abstract

Two decades ago, Perrot and March [F. Perrot and N.H. March, Phys. Rev. A. 41, 4521 (1990)] used electron theory to derive an oscillatory pair potential between the beryllium nuclei in liquid metal beryllium. They predict a first minimum at 2.1 Å, followed by a larger repulsive hump at 2.8 Å. Here, we compare and contrast this result for liquid beryllium with the recent ab initio work by Koput and the present quantum Monte Carlo (QMC) calculation on the beryllium dimer in free space. Koput situates the minimum in the potential curve for the free-space dimer at 2.4 Å and it is quite similar in depth to that for liquid metallic beryllium. Our QMC curve is similar, with the minimum at 2.33 Å. They are tabulated in this letter.