utility_panel.py

            cube.parent = atom.parent
            cube.hide_set(True)
            electron1.hide_set(True)
            electron2.hide_set(True)
            lamp1.hide_set(True)
            lamp2.hide_set(True)

    # Deselect everything
    bpy.ops.object.select_all(action='DESELECT')
    # Make the old atom visible.
    atom.hide_set(True)
    # Select the old atom.
    atom.select_set(True)
    # Remove the parent if necessary.
    atom.parent = None
    # Unlink the old object from the collection.
    coll_atom.objects.unlink(atom)
    # Delete the old atom
    bpy.ops.object.delete()

    return new_atom


# Initialization of the list 'ELEMENTS'.
def read_elements():

    del ELEMENTS[:]

    for item in ELEMENTS_DEFAULT:

        # All three radii into a list
        radii = [item[4],item[5],item[6]]
        # The handling of the ionic radii will be done later. So far, it is an
        # empty list.
        radii_ionic = item[7:]

        li = ElementProp(item[0],item[1],item[2],item[3],
                                     radii,radii_ionic)
        ELEMENTS.append(li)


# Custom data file: changing color and radii by using the list 'ELEMENTS'.
def custom_datafile_change_atom_props():

    for atom in bpy.context.selected_objects:
        if len(atom.children) != 0:
            child = atom.children[0]
            if child.type in {'SURFACE', 'MESH', 'META'}:
                for element in ELEMENTS:
                    if element.name in atom.name:
                        child.scale = (element.radii[0],) * 3
                        child.active_material.diffuse_color = element.color
        else:
            if atom.type in {'SURFACE', 'MESH', 'META'}:
                for element in ELEMENTS:
                    if element.name in atom.name:
                        atom.scale = (element.radii[0],) * 3
                        atom.active_material.diffuse_color = element.color


# Reading a custom data file and modifying the list 'ELEMENTS'.
def custom_datafile(path_datafile):

    if path_datafile == "":
        return False

    path_datafile = bpy.path.abspath(path_datafile)

    if os.path.isfile(path_datafile) == False:
        return False

    # The whole list gets deleted! We build it new.
    del ELEMENTS[:]

    # Read the data file, which contains all data
    # (atom name, radii, colors, etc.)
    data_file_p = open(path_datafile, "r")

    for line in data_file_p:

        if "Atom" in line:

            line = data_file_p.readline()
            # Number
            line = data_file_p.readline()
            number = line[19:-1]
            # Name
            line = data_file_p.readline()
            name = line[19:-1]
            # Short name
            line = data_file_p.readline()
            short_name = line[19:-1]
            # Color
            line = data_file_p.readline()
            color_value = line[19:-1].split(',')
            color = [float(color_value[0]),
                     float(color_value[1]),
                     float(color_value[2]),
                     float(color_value[3])]
            # Used radius
            line = data_file_p.readline()
            radius_used = float(line[19:-1])
            # Atomic radius
            line = data_file_p.readline()
            radius_atomic = float(line[19:-1])
            # Van der Waals radius
            line = data_file_p.readline()
            radius_vdW = float(line[19:-1])
            radii = [radius_used,radius_atomic,radius_vdW]
            radii_ionic = []

            element = ElementProp(number,name,short_name,color,
                                              radii, radii_ionic)

            ELEMENTS.append(element)

    data_file_p.close()

    return True