Benchmark potential energy curve for collinear H$_3$

TL;DR

This paper presents a highly accurate benchmark potential energy curve for collinear H$_3$, achieved through advanced ECG methods and optimized computational techniques, providing a valuable reference for future theoretical studies.

Contribution

It introduces a new ECG-based approach with optimized initialization to compute a benchmark-quality potential energy curve for H$_3$, surpassing previous methods in accuracy and efficiency.

Findings

Achieved sub-parts-per-billion precision in energy calculations.

Reduced computational cost with optimized fragment initialization.

Produced a highly accurate potential energy curve for collinear H$_3$.

Abstract

A benchmark-quality potential energy curve is reported for the H$_3$ system in collinear nuclear configurations. The electronic Schr\"odinger equation is solved using explicitly correlated Gaussian (ECG) basis functions using an optimized fragment initialization technique that significantly reduces the computational cost. As a result, the computed energies improve upon recent orbital-based and ECG computations. Starting from a well-converged basis set, a potential energy curve with an estimated sub-parts-per-billion precision is generated for a series of nuclear configurations using an efficient ECG rescaling approach.