Home
Fanpy: A Python library for prototyping multideterminant methods in ab initio Electronic Structure Calculations
Fanpy is a free, open-source, and cross-platform Python 3 library designed for ab initio electronic structure calculations. The Fanpy implementation is based on the mathematical framework called Flexible Ansatz for N-electron Configuration Interaction (FANCI).
The adoption of the FANCI framework provides a highly modular structure to Fanpy, resulting in five modules: Hamiltonian, Wavefunction, Objective, Solver, and Tools. This modular structure offers two significant advantages. Firstly, it enables a ‘sandbox-like’ approach to handling various combinations of wavefunction ansatz and different methods. Secondly, it simplifies the transition from the theoretical formulation of a method to its practical implementation.
For detailed information about the mathematical formulation, please take a look at the FANCI publication. The official notes of the Fanpy library can be found in this article.