dispersion diagram crystal

Hi, Guy,

I'm studying how to use the plane wave expansion method to calculate the dispersion diagram of photonic crystal W1 waveguide (one row hole missing). Now I have difficulty in setting the supercell for triangular lattice for the projected band. I attached the shematic diagram of its structure and supercell setting. When I use this setting, there're lots of modes in the bandgap. But in the publications, there always plot the even or odd mode in the bandgap. And the plots look very clear. How to plot this kinds of projected dispersion diagram? Could anyone help me to resolve these problems? Many thanks.