Abstract
In case of the motion equation for molecules supposed as represented by a difference equation for the displacement of molecules, LC ladder circuit of a periodic system is obtained as an equivalent circuit. As the LC circuit shows reciprocal and lossless, we can apply the iteration parameter theory and we obtain complex impedances. That is, we have to consider complex power for a one-dimensional crystal, although in kinetic theory a crystal is analyzed by a real function. Since the time integral of complex power denotes energy, reactive power is not related to energy, but is related to oscillation. As the result, we can show that the eigen oscillation of a one-dimensional crystal is caused by reactive power.
