anaddb-irreps 0.1.2

anaddb_irreps: use phonopy to find the irreducible representations of the phonon modes from anaddb output. It is a simple wrapper of the Phonopy irreps module.

anaddb_irreps

A simple wrapper of the phonopy irreps module for finding irreduciple representations of the phonon modes in anaddb output.

Installation

Install from PyPI:

pip install anaddb_irreps

Or from source:

pip install .

Usage (Python API):

• Step 1:

  Run anaddb to get the phbst file with phonon frequencies and eigen vectors inside. See for example in the examples/MoS2_1T/anaddb_input directory.

• Step 2:

  Make a python script with the content similar to below and run it.

from anaddb_irreps import IrRepsAnaddb

def show_phbst_irreps():
    irr = IrRepsAnaddb(
        phbst_fname="run_PHBST.nc",
        ind_q=0,
        symprec=1e-5,
        degeneracy_tolerance=1e-4)
    irr.run()
    irr._show(True)

show_phbst_irreps()

The parameters in the functions:

•  phbst_fname: name of phbst file.
  

•  ind_q: index of the q point in the phbst.
  

•  is_little_cogroup: 
  

•  symprec: precision for deciding the symmetry of the atomic structure.
  

•  degeneracy_tolenrance: the tolerance of frequency difference in deciding the degeneracy.
  

•  log_level: how much information is in the output. 
  

Usage (CLI):

You can use the anaddb-irreps command-line tool as a lightweight alternative to writing a Python script.

Basic example (equivalent to the Python example above):

anaddb-irreps \
  --phbst run_PHBST.nc \
  --q-index 0 \
  --symprec 1e-5 \
  --degeneracy-tolerance 1e-4

Options:

• -p, --phbst (required): Path to PHBST NetCDF file (e.g. run_PHBST.nc).
• -q, --q-index (required): Index of the q-point in the PHBST file (0-based).
• -s, --symprec: Symmetry precision passed to phonopy (default: 1e-5).
• -d, --degeneracy-tolerance: Frequency tolerance for degeneracy detection (default: 1e-4).
• -l, --is-little-cogroup: Use little co-group setting.
• -v, --log-level: Verbosity level passed through to IrRepsAnaddb (default: 0).

The CLI prints the same irreps information as the Python API example.