Pietro's problem was that he was using run-tm and yet asking MPB to solve for a k-direction that broke the tm symmetry (i.e. there was a symmetry CHECK failure at k-direction (0.5,0.1,0.1)). Specifically, it failed because you had a finite kz value. Actually you should not have a finite kz value for your 2-D structure (with continuous symmetry in the z-direction).
If you read the MPB documentation in http://ab-initio.mit.edu/wiki/index.php/MPB_User_Reference#Run_functions, it states: "(run-te band-func ...), (run-tm band-func ...) These are the same as the run function except that they constrain their solutions to be TE- and TM-polarized, respectively, in two dimensions. The TE and TM polarizations are defined has having electric and magnetic fields in the xy plane, respectively.......These functions are actually equivalent to calling run-zeven and run-zodd, respectively" So run-te or run-tm assumes mirror symmetry with respect to the z=0 plane, and therefor you cannot specify a finite kz value. Mahmoud suggestion should work as all his suggested k-directions being solved for are in the x-y plane (i.e. they all maintain mirror symmetry with respect to the z=0 plane). On Mon, 2011-02-21 at 12:00 -0500, [email protected] wrote: > Send mpb-discuss mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of mpb-discuss digest..." > > > Today's Topics: > > 1. Re: mpb-discuss Digest, Vol 60, Issue 5 (2D Photonic Crystal > (PC) vein structure) (mahmoud hamoud) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 20 Feb 2011 09:19:59 -0800 (PST) > From: mahmoud hamoud <[email protected]> > Subject: Re: [MPB-discuss] mpb-discuss Digest, Vol 60, Issue 5 (2D > Photonic Crystal (PC) vein structure) > To: [email protected] > Message-ID: <[email protected]> > Content-Type: text/plain; charset="iso-8859-1" > > ? HI, > > ? try (set! k-points (list (vector3 0 0 0)(vector3 0.5 0 0)(vector3 0.5 0.5 > 0)(vector3 0 0 0))) instead of (set! k-points (list (vector3 0 0 0)(vector3 > 0.5 0 0)(vector3 0.5 0.5 0.5)(vector3 0 0 0))) > > ?? with regards > --- On Sat, 2/19/11, [email protected] <[email protected]> wrote: > > From: [email protected] <[email protected]> > Subject: Re: [MPB-discuss] mpb-discuss Digest, Vol 60, Issue 5 (2D Photonic > Crystal (PC) vein structure) > To: [email protected] > Date: Saturday, February 19, 2011, 11:27 AM > > > Thanks for the suggestion!! > That's what I did: > > > (set! num-bands 8) > > (set! k-points (list (vector3 0 0 0)(vector3 0.5 0 0)(vector3 0.5 0.5 > 0.5)(vector3 0 0 0))) > > (set! k-points (interpolate 4 k-points)) > > (set! geometry (list (make block (center 0 0 0)(material (make dielectric > (epsilon 8.9))) (size 1 1 0)? )? (make block (center 0 0 0)(material > air)(size 0.9175 0.9175 0) )? ? )) > > (set! geometry-lattice (make lattice (size 1 1 no-size))) > > (set! resolution 32) > > (run-tm) > > > bu it computes the eigenvalues only for the first six k sampled values :/ In > fact here's what the output file says: > > > init-params: initializing eigensolver data > Computing 8 bands with 1.000000e-07 tolerance. > Working in 2 dimensions. > Grid size is 32 x 32 x 1. > Solving for 8 bands at a time. > Creating Maxwell data... > Allocating fields... > Mesh size is 3. > Lattice vectors: > ? ???(1, 0, 0) > ? ???(0, 1, 0) > ? ???(0, 0, 1) > Cell volume = 1 > Reciprocal lattice vectors (/ 2 pi): > ? ???(1, -0, 0) > ? ???(-0, 1, -0) > ? ???(0, -0, 1) > Geometric objects: > ? ???block, center = (0,0,0) > ? ? ? ? ? size (1,1,0) > ? ? ? ? ? axes (1,0,0), (0,1,0), (0,0,1) > ? ? ? ? ? dielectric constant epsilon = 8.9 > ? ???block, center = (0,0,0) > ? ? ? ? ? size (0.9175,0.9175,0) > ? ? ? ? ? axes (1,0,0), (0,1,0), (0,0,1) > ? ? ? ? ? dielectric constant epsilon = 1 > Geometric object tree has depth 4 and 19 object nodes (vs. 2 actual objects) > Initializing dielectric function... > 16 k-points: > ? ???(0,0,0) > ? ???(0.1,0,0) > ? ???(0.2,0,0) > ? ???(0.3,0,0) > ? ???(0.4,0,0) > ? ???(0.5,0,0) > ? ??? > ? ???(0.5,0.2,0.2) > ? ???(0.5,0.3,0.3) > ? ???(0.5,0.4,0.4) > ? ???(0.5,0.5,0.5) > ? ???(0.4,0.4,0.4) > ? ???(0.3,0.3,0.3) > ? ???(0.2,0.2,0.2) > ? ???(0.1,0.1,0.1) > ? ???(0,0,0) > Solving for band polarization: tm. > Initializing fields to random numbers... > elapsed time for initialization: 0 seconds. > epsilon: 1-8.9, mean 2.11008, harm. mean 1.18096, 17.8711% > 1, 14.0516% > "fill" > matrixio: cannot output "epsilon" (compiled without HDF) > Outputting epsilon... > solve_kpoint (0,0,0): > tmfreqs:, k index, k1, k2, k3, kmag/2pi, tm band 1, tm band 2, tm band 3, tm > band 4, tm band 5, tm band 6, tm band 7, tm band 8 > Solving for bands 2 to 8... > Finished solving for bands 2 to 8 after 21 iterations. > tmfreqs:, 1, 0, 0, 0, 0, 0, 0.575323, 0.602844, 0.670309, 0.670309, 0.92999, > 1.01749, 1.06308 > elapsed time for k point: 0 seconds. > solve_kpoint (0.1,0,0): > Solving for bands 1 to 8... > Finished solving for bands 1 to 8 after 11 iterations. > tmfreqs:, 2, 0.1, 0, 0, 0.1, 0.0687167, 0.560016, 0.594946, 0.671283, > 0.69278, 0.919441, 1.00776, 1.05038 > elapsed time for k point: 0 seconds. > solve_kpoint (0.2,0,0): > Solving for bands 1 to 8... > Finished solving for bands 1 to 8 after 7 iterations. > tmfreqs:, 3, 0.2, 0, 0, 0.2, 0.136638, 0.517058, 0.59603, 0.673869, 0.732054, > 0.895408, 0.980464, 1.04292 > elapsed time for k point: 1 seconds. > solve_kpoint (0.3,0,0): > Solving for bands 1 to 8... > Finished solving for bands 1 to 8 after 7 iterations. > tmfreqs:, 4, 0.3, 0, 0, 0.3, 0.202632, 0.465482, 0.601488, 0.677142, > 0.772496, 0.86993, 0.9464, 1.04075 > elapsed time for k point: 0 seconds. > solve_kpoint (0.4,0,0): > Solving for bands 1 to 8... > Finished solving for bands 1 to 8 after 6 iterations. > tmfreqs:, 5, 0.4, 0, 0, 0.4, 0.263711, 0.412638, 0.606749, 0.679854, > 0.809602, 0.851224, 0.91268, 1.04004 > elapsed time for k point: 0 seconds. > solve_kpoint (0.5,0,0): > Solving for bands 1 to 8... > Finished solving for bands 1 to 8 after 6 iterations. > tmfreqs:, 6, 0.5, 0, 0, 0.5, 0.299768, 0.379295, 0.608921, 0.680907, > 0.830021, 0.844313, 0.893389, 1.03987 > elapsed time for k point: 0 seconds. > CHECK failure on line 512 of mpb.c: k vector is incompatible with specified > parity > > Some deprecated features have been used.? Set the environment > variable GUILE_WARN_DEPRECATED to "detailed" and rerun the > program to get more information.? Set it to "no" to suppress > this message. > solve_kpoint (0.5,0.1,0.1): > > > I don't get the last code-message. I'm sorry for bothering you. Thank you a > lot for your availability and kindness : ) > > pietro > > > ------------------------------------------------------------------------------- > Valore legale alle tue mail > InterfreePEC - la tua Posta Elettronica Certificata > http://pec.interfree.it > ------------------------------------------------------------------------------- > > > _______________________________________________ > mpb-discuss mailing list > [email protected] > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://ab-initio.mit.edu/pipermail/mpb-discuss/attachments/20110220/7119119e/attachment.html> > > ------------------------------ > > _______________________________________________ > mpb-discuss mailing list > [email protected] > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss > > End of mpb-discuss Digest, Vol 60, Issue 7 > ****************************************** _______________________________________________ mpb-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
