Auxiliary-Field Quantum Monte Carlo
The AFQMC package, called SAFIRE, aims to provide a comprehensive software environment using auxiliary-field quantum Monte Carlo, broadly defined, to study quantum many-fermion systems. The package is designed for large-scale distributed calculations, with GPU support for high performance applications. The aim is to provide a platform for community development and for state-of-the-art applications.
The library will contain a suite of software for
1. correlated electron models and ultracold fermionic atom systems
2. molecular calculations treating standard quantum chemistry Hamiltonians (for example, using Gaussian basis sets)
3. ab initio calculations in extended systems with either Kohn-Sham-orbital-like basis sets or planewaves and pseudopotentials
The software implements importance-sampled branching random walks in non-orthogonal Slater determinant space. A constrained-path or phaseless approximation is used to control the fermion sign or phase problem. Total energy, as well as other observables and correlation functions, is computed.
Upon initial release, the package will use a ground-state, canonical ensemble formalism. Corresponding finite-temperature extensions are also being developed and will be made available to the community.
A pedagogical AFQMC package for model systems, written in Matlab and with a graphical interface, is available at here.
Project Leaders: Miguel Morales, Shiwei Zhang
Project Scientists: Brandon K. Eskridge, Peter Rosenberg, Zhou-Quan Wan, Lukas Weber