Diabatic Hamiltonian matrix elements made simple

TL;DR

This paper introduces a simplified approach for calculating diabatic Hamiltonian matrix elements, enabling efficient application of the Generator Coordinate Method to large configuration spaces without complex two-body interaction evaluations.

Contribution

It proposes an approximate formula that simplifies the computation of diabatic matrix elements, avoiding the need for detailed two-body interaction calculations.

Findings

Effective for large configuration spaces

Validated with analytically solvable harmonic oscillator models

Reduces computational complexity

Abstract

With a view to applying the Generator Coordinate Method to large configuration spaces, we propose a simple approximate formula to compute diabatic many-body matrix elements without having to evaluate two-body interaction matrix elements. The method is illustrated with two analytically solvable Hamiltonians based on the harmonic oscillator.