Be2+(aq) hydrolysis can to lead to the formation of multi-beryllium clusters, but the thermodynamics of this process has not been resolved theoretically. We study the hydration state of an isolated Be2+ ion using both the quasi-chemical theory of solutions and ab initio molecular dynamics. These studies confirm that Be2+(aq) is tetra-hydrated. The quasi-chemical approach is then applied to then the deprotonation of Be(H_2O)_4^{2+}} to give BeOH(H_2O)_3{}^{+}}. The calculated pKa of 3.8 is in good agreement with the experimentally suggested value around 3.5. The calculated energetics for the formation of BeOHBe3+ are then obtained in fair agreement with experiments.
@article{arxiv.physics/0301024,
title = {Quasi-chemical study of Be$^{2+}$(aq) speciation},
author = {D. Asthagiri and Lawrence R. Pratt},
journal= {arXiv preprint arXiv:physics/0301024},
year = {2009}
}