def modulation(self):
        m = self.m
        conf = """
        DIM = %s
        MODULATION = 1 1 1, 0 0 0 0 1 0
        ATOM_NAME = %s
        FORCE_CONSTANTS = READ
        """ % (m.dim, ' '.join(m.elements))
        write(conf, 'modulation.conf')

        passthru(config.phonopy + "--tolerance=1e-4    modulation.conf")