Setting up the options for and defining custom materials

    from solcore import material
    from solcore import si
    from solcore.material_system import create_new_material
    from solcore.absorption_calculator import create_nk_txt, download_db, search_db
    from solcore.config_tools import add_source
    import matplotlib.pyplot as plt
    import numpy as np
    import os

# When adding custom materials - or getting the refractive index database - the
# information will be stored in the Solcore's users folder. These can be setup by setting
# the SOLCORE_USER_DATA environmental variable to your prefered location or, by default,
# it will be in your home directory, in a directory called .solcore.

    # EXAMPLE 1

    # need to have n and k data, and a parameter file in the correct format -
    # see examples of parameter files in e.g. material_data/Adachi/binaries.txt

    # create a new material, silicon-germanium-tin, from input files. Here,
    # the parameters in SiGeSn_params.txt have been copied directly from Ge.
    create_new_material('SiGeSn', 'SiGeSn_n.txt', 'SiGeSn_k.txt', 'SiGeSn_params.txt')

    # Note that the final argument, the parameter file, is optional - if you do not
    # provide it, a material will be added with optical constants only, so it can be
    # used for optical calculations.

    # can now create an instance of it like any Solcore material
    SiGeSn = material('SiGeSn')()

    plt.figure()
    plt.plot(si(np.arange(300, 1700, 5), 'nm')*1e9, SiGeSn.n(si(np.arange(300, 1700, 5), 'nm')))
    plt.plot(si(np.arange(300, 1700, 5), 'nm')*1e9, SiGeSn.k(si(np.arange(300, 1700, 5), 'nm')))
    plt.show()

    # EXAMPLE 2
    # Can also create a Solcore material from a material in the refractiveindex.info database:

    # if necessary, download database:
    download_db()

    # search what options are available for diamond, then use the first result's pageid to
    # create data files for the n & k of diamond:

    results = search_db('Diamond')
    create_nk_txt(pageid=results[0][0], file='C_Diamond')
    create_new_material(mat_name = 'Diamond', n_source='C_Diamond_n.txt', k_source='C_Diamond_k.txt')

    Diamond = material('Diamond')()

    plt.figure()
    plt.plot(si(np.arange(100, 800, 5), 'nm')*1e9, Diamond.n(si(np.arange(100, 800, 5), 'nm')))
    plt.plot(si(np.arange(100, 800, 5), 'nm')*1e9, Diamond.k(si(np.arange(100, 800, 5), 'nm')))
    plt.show()