def METHOD_NAME(self):
    """Fill up the atomic orbitals with available electrons.
    Returns:
        HOMO, LUMO, and whether it's a metal.
    """
    orbitals = self.aos_as_list()
    electrons = Composition(self.composition).total_electrons
    partial_filled = []
    for orbital in orbitals:
        if electrons <= 0:
            break
        if "s" in orbital[1]:
            electrons += -2
        elif "p" in orbital[1]:
            electrons += -6
        elif "d" in orbital[1]:
            electrons += -10
        elif "f" in orbital[1]:
            electrons += -14
        partial_filled.append(orbital)
    if electrons != 0:
        homo = partial_filled[-1]
        lumo = partial_filled[-1]
    else:
        homo = partial_filled[-1]
        try:
            lumo = orbitals[len(partial_filled)]
        except Exception:
            lumo = None
    return {"HOMO": homo, "LUMO": lumo, "metal": homo == lumo}