@classmethod
def _convert_material_parameters(cls, mat_props):
    """Handle exceptions for converting input material dict in Standard Form.

        Returns
        -------
        dict
            Material properties converted to Standard Form.

        Raises
        ------
        TypeError
            If mat_props is neither in Quick or Standard Form, but requires to
            be written as a nested dict.

        """
    try:
        if mat_props is None:
            dict_prop = {}
        elif isinstance(mat_props, dict):
            mat_props['Modulus'].keys()
            dict_prop = mat_props
        else:
            raise TypeError(
                'Nested dict of material parameters required.  See Tutorial.')
    except KeyError:
        print('Converting mat_props to Standard Form.')
        dict_prop = cls._to_standard_dict(mat_props)
    return dict_prop
