PWE_PBS_3Dfcc

代码说明：

  Calculates photonic band structure for either an fcc or diamond lattice of dielectric spheres of dielectric constant epsilon_a in a dielectric background of dielectric constant epsilon_b.(Calculates photonic band structure for ei ther'isnt an fcc or diamond lattice of dielectric v. eres of dielectric constant in a diel epsilon_a ectric background of dielectric constant epsi lon_b.)