Projection method for rapid ab initio calculations of metals

TL;DR

This paper introduces an improved projection-based method derived from the Energy Renormalization Group technique, enabling faster ab initio calculations for metals, demonstrated on a one-dimensional tight-binding model.

Contribution

It presents a novel enhancement of the Energy Renormalization Group method using Feshbach projection techniques for efficient calculations in small-gap systems.

Findings

Accurate ground state energy calculations for the 1D tight-binding model.

Method significantly reduces computational time compared to traditional approaches.

Validated effectiveness for systems with small electronic gaps.

Abstract

An improvement of the Energy Renormalization Group method is proposed for systems with small gap, based on the projection methods developed by H. Feshbach. It is tested for the ground state energy of the one-dimensional tight-binding model.