Hello Steven & MPB users,
I'm trying to simulate the photonic band structure of an FCC lattice with
random sphere sizes. I'm working with a supercell of size n (where n is a
variable) and then I want to fill the cell with spheres on the lattice sites
with random sizes. To this end, I have written a do loop to fill in the
lattice points. However I'm not sure how to append the lists created on my
loop to return a full list of objects back. Below is my code: nx ny nx
denote the 1x1x1 box I'm in, where each box is just the cubic non-primitive
unit cell of the FCC lattice. In each box I fill in the objects at the four
basis points: one corner and three faces. I do this for each box in my super
cell. I'm just not sure how to append the lists I make in my loop to return
it back to set! geometry.
Any help would be appreciated.
Thanks,
Ian
; Dielectric dimers in a rotator phase, FCC lattice
(define-param n 2) ; super cell number of repeat units
(define-param a (sqrt 0.5) ) ; primitive lattice vector magnitude
(define-param r (/ a 2)) ; the radius of rotation
(set! default-material (make dielectric (epsilon (* 3.5 3.5))))
(define (place-particle xx yy zz)
(make sphere (center xx yy zz) (radius (* 1 r))
(material (make dielectric (epsilon 1))))
)
(define (fill-lattice)
(do ((nx 0 (+ nx 1))) ((> nx (- n 1)))
(do ((ny 0 (+ ny 1))) ((> ny (- n 1)))
(do ((nz 0 (+ nz 1))) ((> nz (- n 1)))
(list
(place-particle nx ny nz)
(place-particle (+ nx a) (+ ny a) nz)
(place-particle (+ nx a) ny (+ nz a))
(place-particle nx (+ ny a) (+ nz a))
)
)
)
)
)
(set! geometry-lattice (make lattice
(basis-size a a a)
(basis1 0 1 1)
(basis2 1 0 1)
(basis3 1 1 0)
(size n n n)
)
)
; A super cell lattice of n has n "atoms" per unit cell:
(set! geometry
(fill-lattice) ;
)
; Corners of the irreducible Brillouin zone for the fcc lattice,
; in a canonical order:
(set! k-points (interpolate 4 (list
(vector3 0 0.5 0.5) ; X
(vector3 0 0.625 0.375) ; U
(vector3 0 0.5 0) ; L
(vector3 0 0 0) ; Gamma
(vector3 0 0.5 0.5) ; X
(vector3 0.25 0.75 0.5) ; W
(vector3 0.375 0.75 0.375)))) ; K
(set-param! resolution 16) ; use a 16x16x16 grid
(set-param! mesh-size 5)
(set-param! num-bands 5)
; run calculation:
(run)
_______________________________________________
mpb-discuss mailing list
[email protected]
http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
