Example for SAMB Construction

Example for SAMB Construction#

  1. Prepare input file. Example input files for C3v molecule and graphene are given as follows.

    • C3v molecule

    # C3v.py
"""
input file for C3v molecule.
"""
C3v = {
    "model": "C3v",  # name of model.
    "group": "C3v-1",  # name of point group.
    "cell": {"c": 10},  # set large enough interlayer distance.
    #
    "site": {"A": ("[-1/6,-1/6,0]", "s"), "B": ("[-2/3,0,0]", "p")},  # positions of A and B sites and their orbitals.
    "bond": [("A", "A", 1), ("A", "B", 1)],  # nearest-neighbor A-A and B-B bonds.
    #
    "spinful": False,  # spinless.
}

    • graphene

    # graphene.py
"""
input file for graphene.
"""
graphene = {
    "model": "graphene",  #  name of model.
    "group": 191,  # No. of space group.
    "cell": {"c": 4},  # set large enough interlayer distance.
    #
    "site": {"C": ("[1/3,2/3,0]", "pz")},  # positions of C site and its orbital.
    "bond": [("C", "C", [1, 2, 3, 4, 5, 6])],  # C-C bonds up to 6th neighbors.
    #
    "spinful": False,  # spinless.
    #
    "k_point": {"Γ": "[0, 0, 0]", "M": "[1/2, 0, 0]", "K": "[1/3, 1/3, 0]"},  # def. of k points.
    "k_path": "Γ-K-M-Γ",  # high-symmetry line.
}

  2. At the folder where the input file exists, do the following to create SAMB. See for more detail, try create_samb --help command.

    $ create_samb C3v graphene

  3. The following files are created in C3v and graphene folders.

    • C3v_model.py, C3v_samb.py, C3v_matrix.py, C3v_samb.tex, C3v_samb.pdf, C3v_view.qtdw

    • graphene_model.py, graphene_samb.py, graphene_matrix.py, graphene_samb.tex, graphene_samb.pdf, graphene_view.qtdw

    Here, .tex and .pdf are created if TeXLive is installed, and .qtdw is created if QtDraw is installed.

    Each file contains

    • _model.py : model information.

    • _samb.py : detailed information on SAMB.

    • _matrix.py : full-matrix form of SAMB.

    • _samb.tex and _samb.pdf : detailed information on SAMB in LaTeX and PDF format.

    • _view.qtdw : molecular or crystal structure file for QtDraw.

The detailed file formats are given in File Format section.