Ab initio full cell dynamical mean-field theory (DMFT) and GW+DMFT for solids based on PySCF

Authors: Tianyu Zhu ([email protected]), Huanchen Zhai, Zhihao Cui, Linqing Peng, Garnet Chan

• Prerequisites

  • PySCF 1.7 or higher, and all dependencies
  • libdmet (by Zhi-Hao Cui, https://github.com/gkclab/libdmet_preview)
  • block2 (optional, by Huanchen Zhai, https://github.com/block-hczhai/block2-preview)
  • CheMPS2 (optional)

• You need to set environment variable PYTHONPATH to export fcdmft to Python. E.g. if fcdmft is installed in /opt, your PYTHONPATH should be

    export PYTHONPATH=/opt/fcdmft:$PYTHONPATH
  

• Full cell G₀W₀+DMFT and HF+DMFT (mixed MPI and OpenMP parallelization)

• Hamiltonian-based impurity solvers

  • Coupled-cluster Green's function
  • Quantum chemistry dynamical DMRG (from block2)
  • DMRG-MRCI Green's function (from block2)
  • FCI/ED Green's function (from CheMPS2, for test only)

• Molecular and periodic G₀W₀

• Molecular and periodic RPA

• CAS-CI treatment of the impurity problem

You can find Python scripts for running DMFT calculations in /fcdmft/examples. For example, in /fcdmft/examples/Si, the steps to run a full cell GW+DMFT calculation are:

1. Perform DFT and GW calculations by running si_gw.py (Note: For large systems, GW should be performed separately using multiple nodes, i.e. MPI, see /fcdmft/examples/NiO);

2. Derive impurity Hamiltonian and GW double counting term by running si_set_ham.py;

3. Perform GW+DMFT calculation by running run_dmft.py (serial or MPI/OpenMP). All DMFT parameters should be set in run_dmft.py. In this example, CCSD-GF is used as impurity solver. See run_dmft for sample Slurm submission script.

4. (Optional) One may use a CAS-CI treatment when solving the impurity problem. See CAS-CCSD/run_dmft.py for setting CAS-related parameters.

Please cite the following papers in publications utilizing the fcdmft package:

• T. Zhu and G. K.-L. Chan, Phys. Rev. X 11, 021006 (2021)

• T. Zhu, Z.-H. Cui, and G. K.-L. Chan, J. Chem. Theory Comput. 16, 141-153 (2020)

• T. Zhu, C. A. Jimenez-Hoyos, J. McClain, T. C. Berkelbach, and G. K.-L. Chan, Phys. Rev. B 100, 115154 (2019)

Cite the following paper if GW code is used:

• T. Zhu and G. K.-L. Chan, J. Chem. Theory Comput. 17, 727-741 (2021)

Cite the following paper if libdmet package is used:

• Z.-H. Cui, T. Zhu, and G. K.-L. Chan, J. Chem. Theory Comput. 16, 119-129 (2020)