Then https://www.webelements.com/silicon/crystal_structure.html is wrong !
Before you start calculations you should know the crystal structure very well and you should know about symmetry and space groups. Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." ==================================== Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden ________________________________________ Von: wien-boun...@zeus.theochem.tuwien.ac.at [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von Muhammad Sajjad [sajja...@gmail.com] Gesendet: Donnerstag, 10. September 2015 14:51 An: A Mailing list for WIEN2k users Betreff: Re: [Wien] Si under strain It is 216_F-43m On Thu, Sep 10, 2015 at 1:51 PM, Muhammad Sajjad <sajja...@gmail.com<mailto:sajja...@gmail.com>> wrote: Here is the structure file script. Title F LATTICE,NONEQUIV.ATOMS: 2 216_F-43m MODE OF CALC=RELA unit=ang 10.263031 10.263031 10.263031 90.000000 90.000000 90.000000 ATOM 1: X=0.00000000 Y=0.00000000 Z=0.00000000 MULT= 1 ISPLIT= 2 Si NPT= 781 R0=0.00010000 RMT= 2.21 Z: 14.0 LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 ATOM 2: X=0.25000000 Y=0.25000000 Z=0.25000000 MULT= 1 ISPLIT= 2 Si NPT= 781 R0=0.00010000 RMT= 2.21 Z: 14.0 LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 24 NUMBER OF SYMMETRY OPERATIONS 1 0 0 0.00000000 0-1 0 0.00000000 0 0-1 0.00000000 1 1 0 0 0.00000000 0 0-1 0.00000000 0-1 0 0.00000000 2 0 1 0 0.00000000 -1 0 0 0.00000000 0 0-1 0.00000000 3 0 0 1 0.00000000 -1 0 0 0.00000000 0-1 0 0.00000000 4 0 1 0 0.00000000 0 0-1 0.00000000 -1 0 0 0.00000000 5 0 0 1 0.00000000 0-1 0 0.00000000 -1 0 0 0.00000000 6 0-1 0 0.00000000 1 0 0 0.00000000 0 0-1 0.00000000 7 0 0-1 0.00000000 1 0 0 0.00000000 0-1 0 0.00000000 8 -1 0 0 0.00000000 0 1 0 0.00000000 0 0-1 0.00000000 9 -1 0 0 0.00000000 0 0 1 0.00000000 0-1 0 0.00000000 10 0-1 0 0.00000000 0 0-1 0.00000000 1 0 0 0.00000000 11 0 0-1 0.00000000 0-1 0 0.00000000 1 0 0 0.00000000 12 0 0 1 0.00000000 0 1 0 0.00000000 1 0 0 0.00000000 13 0 1 0 0.00000000 0 0 1 0.00000000 1 0 0 0.00000000 14 -1 0 0 0.00000000 0 0-1 0.00000000 0 1 0 0.00000000 15 -1 0 0 0.00000000 0-1 0 0.00000000 0 0 1 0.00000000 16 0 0 1 0.00000000 1 0 0 0.00000000 0 1 0 0.00000000 17 0 1 0 0.00000000 1 0 0 0.00000000 0 0 1 0.00000000 18 0 0-1 0.00000000 0 1 0 0.00000000 -1 0 0 0.00000000 19 0-1 0 0.00000000 0 0 1 0.00000000 -1 0 0 0.00000000 20 0 0-1 0.00000000 -1 0 0 0.00000000 0 1 0 0.00000000 21 0-1 0 0.00000000 -1 0 0 0.00000000 0 0 1 0.00000000 22 1 0 0 0.00000000 0 0 1 0.00000000 0 1 0 0.00000000 23 1 0 0 0.00000000 0 1 0 0.00000000 0 0 1 0.00000000 24 On Wed, Sep 9, 2015 at 10:52 PM, Gavin Abo <gs...@crimson.ua.edu<mailto:gs...@crimson.ua.edu>> wrote: Did you send the wrong scfmbj.struct? At least for me, "x nn" of WIEN2k 14.2 gives WARNINGS that the struct file is not okay. username@computername:~/wiendata/scfmbj$ ls scfmbj.struct username@computername:~/wiendata/scfmbj$ x nn specify nn-bondlength factor: (usually=2) [and optionally dlimit, dstmax (about 1.d-5, 20)] 2 DSTMAX: 20.0000000000000 iix,iiy,iiz 4 4 5 41.0521240000000 41.0521240000000 51.3151550000000 ATOM 1 Si ATOM 2 Si RMT( 1)=2.21000 AND RMT( 2)=2.21000 SUMS TO 4.42000 LT. NN-DIST= 4.44402 ATOM 2 Si ATOM 1 Si RMT( 2)=2.21000 AND RMT( 1)=2.21000 SUMS TO 4.42000 LT. NN-DIST= 4.44402 WARNING: Mult not equal. PLEASE CHECK outputnn-file WARNING: Mult not equal. PLEASE CHECK outputnn-file WARNING: ityp not equal. PLEASE CHECK outputnn-file NN created a new scfmbj.struct_nn file NN created a new CASE.STRUCT_NN FILE 0.0u 0.0s 0:01.35 0.0% 0+0k 0+32io 0pf+0w On 9/9/2015 8:48 AM, Muhammad Sajjad wrote: Dear user I computed Si BS for the structure (scfmbj.struct) attached herewith. When I apply strain (a+a*0.01, b, c-c*0.01) then symmetry changes (space group 1_P1). WIth this group calculations does not run every times QTLB error appears and I have done my best to apply each solution for it. Secondly I got structure from wien2k examples. That works fine but when strain is applied then it behaves as a metal. Though this work has been done many times but I can not find my solution. I found VASP study but not wien2k study. In VASP POSCAR is cubic diamond 5.50000000000000 0.0000000000000000 0.4969432792132343 0.4969432792132343 0.4969432792132343 0.0000000000000000 0.4969432792132343 0.4969432792132343 0.4969432792132343 0.0000000000000000 Si 2 Direct 0.8750000000000000 0.8750000000000000 0.8750000000000000 0.1250000000000000 0.1250000000000000 0.1250000000000000 I changed this POSCAR to cif and used for wien2k (structure is attached TEST.struct) , then BS is correct, but after application of strain (1%) again it becomes metal. I do not know how to apply strain in POSCAR. Could you please guide me? Kind Regards Muhammad Sajjad Post Doctoral Fellow KAUST, KSA. _______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at<mailto:Wien@zeus.theochem.tuwien.ac.at> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html -- Kind Regards Muhammad Sajjad Post Doctoral Fellow KAUST, KSA. -- Kind Regards Muhammad Sajjad Post Doctoral Fellow KAUST, KSA. _______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html