Installation ************ Prerequisites ------------- * Python :code:`3.10 <= version < 3.13` * PySCF library * Numpy * Scipy * `libDMET `__ (required for periodic BE) * `Wannier90 `_ :sup:`##` | :sup:`##` :code:`Wannier90` code is optional and only necessary to use Wannier functions in periodic code. The required dependencies, with the exception of the optional :code:`Wannier90`, are automatically installed by :bash:`pip`. Documentation ------------- To build the documentation locally, do .. code-block:: bash cd docs make html or .. code-block:: bash cd docs make latexpdf Installation ------------- One can just :bash:`pip install` directly from the Github repository .. code-block:: bash pip install git+https://https://github.com/troyvvgroup/quemb Alternatively one can manually clone and install as in .. code-block:: bash git clone --recurse-submodules https://https://github.com/troyvvgroup/quemb cd quemb pip install . Known issues and troubleshooting -------------------------------- On macOS, the system-provided Clang compiler does not support OpenMP out of the box. To enable OpenMP, it is recommended to use `Homebrew `_ to install either GCC or LLVM/Clang with the OpenMP runtime. **Option 1 - GCC (includes OpenMP support by default):** .. code-block:: bash brew install gcc CXX=$(brew --prefix gcc)/bin/g++ pip install . **Option 2 - LLVM/Clang with OpenMP runtime:** .. code-block:: bash brew install llvm libomp CXX=$(brew --prefix llvm)/bin/clang++ pip install . Optional dependencies --------------------- If you want to use the ORCA backend for Hartree-Fock you need to install ORCA from `here `_. This requires a registration and is free for academic use. In addition you need to install the python interface via: .. code-block:: bash pip install orca-pi