GFCCLib: Scalable and Efficient Coupled-Cluster Green's Function Library for Accurately Tackling Many Body Electronic Structure Problems

TL;DR

GFCCLib is a specialized computational library that significantly improves the scalability and efficiency of coupled-cluster Green's function calculations, enabling accurate electronic structure analysis of large molecules like C60.

Contribution

This work introduces a scalable, efficient GFCC library designed for large-scale electronic structure calculations, overcoming previous computational bottlenecks.

Findings

Successfully computed the near valence band of C60 at GFCCSD level

Demonstrated excellent agreement with experimental spectra

Achieved improved scalability and efficiency in GFCC calculations

Abstract

Coupled cluster Green's function (GFCC) calculation has drawn much attention in the recent years for targeting the molecular and material electronic structure problems from a many body perspective in a systematically improvable way. However, GFCC calculations on scientific computing clusters usually suffer from expensive higher dimensional tensor contractions in the complex space, expensive interprocess communication, and severe load imbalance, which limits it's routine use for tackling electronic structure problems. Here we present a numerical library prototype that is specifically designed for large scale GFCC calculations. The design of the library is focused on a systematically optimal computing strategy to improve its scalability and efficiency. The performance of the library is demonstrated by the relevant profiling analysis of running GFCC calculations on remote giant computing clusters. The capability of the library is highlighted by computing a wide near valence band of a fullerene C60 molecule for the first time at the GFCCSD level that shows excellent agreement with the experimental spectrum.