About non-existence of the molecular ion $\bf H_3^{++}$

TL;DR

This paper demonstrates that the molecular ion H3++ cannot exist as an equilateral triangle, using a novel variational approach that outperforms standard quantum chemistry methods in energy calculations.

Contribution

It introduces a new compact variational method with tailored trial functions and optimized parameters, providing strong evidence against the existence of H3++ in a triangular form.

Findings

Variational results show H3++ does not form an equilateral triangle.

The method yields lower energy estimates than standard quantum chemistry.

Supports the non-existence of H3++ in the proposed geometry.

Abstract

It is shown that the molecular ion ${\rm H}^{++}_3$ does not exist in a form of the equilateral triangle. To this end, a compact variational method is presented which is based on a linear superposition of six specially tailored trial functions containing non-linear parameters. Careful optimization of a total of fifteen parameters gives consistently lower variational results for the electronic energy than can be obtained with standard methods of quantum chemistry even with huge basis sets as large as mcc-pV7Z.