Calculations of the ground states of BeH and BeH+ without the Born-Oppenheimer approximation

Energetics and reactivity of small beryllium deuterides

Enthalpies and free energies of reaction for small neutral and charged beryllium deuterides BeD, BeD₂, and BeD₃ that have been calculated are reported for a temperature range of 0 K to 1000 K. We discuss probable dissociation channels and possible ways of producing BeD by localizing the relevant transition states and by calculating corresponding rate constants. BeD and BeD⁺ are found to be the most stable ones among the considered compounds. BeD₂ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mathrm{BeD}}_2^{+} $$\end{document}BeD2+ are more likely to decompose into Be^0,+ + D₂ than into BeD^0,+ + D. The metastable BeD₃ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mathrm{BeD}}_3^{+} $$\end{document}BeD3+ predominantly decompose into BeD^0,+ + D₂. In light of our results on the reaction energetics, we can interpret the pathways for production of BeD via BeD₂ and BeD₃ intermediates observed in molecular dynamics simulations.

Ab initio ground-state potential energy functions of beryllium monohydride ions: BeH+ and BeH-

The accurate ground-state potential energy functions of beryllium monohydride (BeH) cation and anion have been determined from ab initio calculations using the multi-reference averaged coupled-pair functional (MR-ACPF) method in conjunction with the correlation-consistent core-valence basis sets up to septuple-zeta quality. The effects of electron correlation beyond the MR-ACPF level of approximation, as well as the scalar relativistic and adiabatic corrections were taken into account. The vibration-rotation energy levels of the BeH, BeD, and BeT isotopologues of both ions were predicted to near "spectroscopic" accuracy. The results can be useful in a future experimental detection of the BeH anion by high-resolution vibration-rotation spectroscopy.