Calculating matrix elements of chiral 3N interactions under JJ-coupled three-body partial-wave basis (in Jacobi coordinates), written in C++.
- This code requires openmp only.
- A C++ compiler with a makefile would be enough. So I provide an exmaple in “Makefile”.
- However, I use Xmake personally, which is a lightweight and fast building utility based on lua. See “xmake.lua”.
To do partial-wave projection for 3N interactions, I follow the "aPWD" method developed by J. Golak. See "A new way to perform partial wave decompositions of few-nucleon forces" if interested.
- src/constants.hpp: definitions of LECs, mesh points and other things. You need to change these for your use.
- src/precalculate.hpp: some functions and structures used to precalculate and store in the beginning of calculation. This is necessary to speed up the code.
- src/aPWD3.hpp: doing partial-wave decomposition for 3N force under JJ-coupled states. This file is rather big because we do it analytically, generated by Mathematica.
- src/main.hpp: the main function, doing angular integration and calculating and storing in specific partial-wave channels.
- tools/*.py: some simple python tools to generate mesh points, channels index and some other useful things.
- apwd3.py: a simple and direct code to do above things using python. This is just a template code for benchmark, running very slow.
- xmake.lua: Xmake’s project description file.
- Makefile: usual building file.
- data/: directory of storing 3BMEs.
This code is mainly designed for generating non-locally regulated 3N interaction in the Jacobi coordinate (up to N2LO). However, it is possible to extend for local 3N interaction or for N3LO terms.
If you have any needs or questions, just contact me: rongzhe_hu@pku.edu.cn or rongzhehuu@gmail.com !