Fwd: question

---------- Forwarded message ----------
From: maryam saberi <[email protected]>
Date: Nov 14, 2007 2:15 PM
Subject: Re: [MPB-discuss] question
To: nate lipkowitz <[email protected]>


Hi
Thank you very much for your help.

I also want to simulate a core-shell fcc structure ( core with
dielectric constant epsilon1 +  shell with dielectric constant
epsilon2)
by mpb, but I don't know how to define dielectric constant of
spheres(core+shell).

I think that I should use of a Step Function, but I can't define it in program.

In addition, how can I define and run the program along a special
direction, for example [1 1 1].






On 11/13/07, nate lipkowitz <[email protected]> wrote:
> hi, this is what i use.  as steven notes in the manual (which you
> should have read) the fcc unit cell has an edge length of sqrt(2)
> times the diameter of your spheres, so you need to take that factor
> into account if you convert the freqs output by mpb to real frequency
> units.
>
> anyway here is the ctl file.. cheers:
>
>
> (set! num-bands 10)
> (set! default-material (make dielectric (index 3.9)))
> (set! resolution 16)
> (set! mesh-size 5)
>
>
>
> (set! geometry-lattice
>   (make lattice
>     (basis1 0 1 1)
>     (basis2 1 0 1)
>     (basis3 1 1 0)
>     (basis-size (sqrt 0.5) (sqrt 0.5) (sqrt 0.5))
>     (size 1 1 1)
>   )
> )
>
> (set! geometry
>   (list
>     (make sphere
>       (center 0 0 0)
>       (radius (/ (sqrt 0.5) 2))
>       (material
>         (make dielectric
>           (index 1.0)
>         )
>       )
>     )
>   )
> )
>
>
> (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
>     )
>   )
> )
>
> (run)
>
>
>
>
> maryam saberi <[email protected]> wrote:
>
> > Hello
> > I' d like simulate a fcc inverse opal structure with Mit Photonic Bands
> > package, but I don't know how to write it's program.
> > Please help me.
> > thanks
> >
>
>
>
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> nate lipkowitz
> 416 823 8057
> [email protected]
>
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