Dear Prof. Johnson and mpb users: I calculated the mode of slab by using the ctl example file ,which is hole-slab.ctl . I saw that the second band and the third band is overlap and the fourth band and the fifth band is overlap . but the first one isalone .I think the true case is that the second band and the third band belong to the same band , and the fourth band and the fifth band belong to another one . the split of the band arise from the useing of supercell . Is the opinion right ? are there any means to gain a band without split ?
the code (define-param h 0.5) ; the thickness of the slab (define-param eps 12.0) ; the dielectric constant of the slab (define-param loweps 1.0) ; the dielectric constant of the substrate (define-param r 0.3) ; the radius of the holes (define-param supercell-h 4) ; height of the supercell ; triangular lattice with vertical supercell: (set! geometry-lattice (make lattice (size 1 1 supercell-h) (basis1 (/ (sqrt 3) 2) 0.5) (basis2 (/ (sqrt 3) 2) -0.5))) (set! geometry (list (make block (material (make dielectric (epsilon loweps))) (center 0 0 (* 0.25 supercell-h)) (size infinity infinity (* 0.5 supercell-h))) (make block (material (make dielectric (epsilon eps))) (center 0) (size infinity infinity h)) (make cylinder (material air) (center 0) (radius r) (height supercell-h)))) ; 1st Brillouin zone of a triangular lattice: (define Gamma (vector3 0 0 0)) (define M (vector3 0 0.5 0)) (define K (vector3 (/ -3) (/ 3) 0)) (define-param only-K false) ; run with only-K=true to only do this k-point (define-param k-interp 4) ; the number of k points to interpolate (if only-K (set! k-points (list K)) (set! k-points (interpolate k-interp (list Gamma M K Gamma)))) (set-param! resolution (vector3 32 32 32)) (set-param! num-bands 9) ; Run even and odd bands, outputting fields only at the K point: (run-zeven (output-at-kpoint K output-hfield-z))
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