An efficient implementation of atomic relativistic four-component Hartree-Fock calculation with spherical symmetry and two-electron Coulomb and Breit interaction. The X2CAMF program can generate spin-orbit integrals within the exact two-component theory with atomic-mean-field integral (the X2CAMF scheme, which has the same name as the program).
The X2CAMF program is a free open-source software.
For a detailed description of X2CAMF scheme and the implementation of spherical symmetry, please see https://pubs.acs.org/doi/pdf/10.1021/acs.jpca.2c02181.
The X2CAMF program has been embarrassingly interfaced with CFOUR and PySCF. The interface to PySCF makes use of pybind.
To install the program, you must have Eigen3 C++ and CMake version >= 3.9. One can modify the cmake list to adjust what to install.
git submodule update --init --recursive (to enable git submodule pybind)
mkdir build
cd build
cmake ..
make
Known problems:
The default stack size is not enough for larger systems. Use "ulimit -s unlimited" to solve this.