Re: [Wien] After supercell, add impurity... x sgroup change space group
Thank you for your feedback As you said, I have clustered the Al on one side of supercell and "layered" like distribution. I've tried different distributions before. I have had some attempts where "x sgroup" gives different space groups. For example, on my last attempt, I replaced the 1st, 4th, 5th, 8th, 9th, 12th, 13th and 18th of the 16 In atoms with Al atoms. (Total: 8 Al + 8 In) - x nn - copy case.struct_nn case.struct (9 atoms: 2 Ag, 1 Al, 1 In, 5 S) - x nn - copy case.struct_nn case.struct (I repeated this step one more time because "x nn" gave warning again). This time 10 atoms: 2 Ag, 1 Al, 1 In, 6 S - x nn - x sgroup And finally the space group turns 20 (C 2 2 21) Orthorombic C-base centered. As a result, a different space group from the original struct file(122_I-42d) was created. In the struct file, the result appears to be OK. 2 Ag: at 4 different positions=8 Ag, 1 Al: at 4 different positions= 4 Al, 1 In: at 4 different positions=4 In, 6 S: at 2+2+4+4+2+2 different positions=16 S I viewed the structure in the xcrysden program. Al and In atoms appear to be homogeneously distributed. I continue the calculation with this struct file and space group. I will share the result with you. Peter Blaha , 25 Oca 2021 Pzt, 21:35 tarihinde şunu yazdı: > It is VERY important to check which In atoms you replace by Al. > View your structure and check: Did you cluster the Al on one side of the > supercell ? Did you introduce a "layered" like distribution ? > > Most likely you want a "random" substitution, without any ordering > (otherwise experiment might have found some order). > > Most likely, the "ideal" randomly substituted structure will even have > P1 spacegroup, i.e. all symmetry operations are lost (at least for a > larger supercell). > > PS: Experiment measures an "average structure", and therefore find a > high symmetry SG. They put on the same position half a In and half a Al > atom. > Of course, this is not reality. > > Am 24.01.2021 um 21:31 schrieb Serhat Ayık: > > Dear Wien2k users, > > In my original struct file, I have (B Lattice) 3 non equiv. atoms > > (Chemical form: AgInS2), space group 122_I-42d, and 8 number of symmetry > > operations. > > I do 2x2x2, P lattice type supercell and I have 48 non equiv. (16 Ag, 16 > > In, 16 S) atoms. I want chemical form like AgAl(0.5)In(0.5)S2. I am > > replacing 8 In atoms with 8 Al atoms. Finally, I have 16 Ag, 8 Al, 8 In > > and 16 S in struct file. > > Then, I do > > - x nn (nn-bondlength factor:2) > > copy case.struct_nn to case.struct. (After this step, I have 7 atoms "2 > > Ag, 1 Al, 1 In, 3 S" in case.struct) > > - repeat x nn > > - x sgroup > > warning: !!! Number of inequivalent atoms has changed. !!! Old value= 48 > > New value= 7 warning: !!! Unit cell has been reduced. > > sgroup found: 17 (P 2 2 21) > > > > I think the space group shouldn't change. > > Is it true that the space group changes? Or am I making a mistake > somewhere? > > > > Regards > > > > > > > > > > > > > > ___ > > 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 > > > > -- > -- > Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna > Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 > Email: bl...@theochem.tuwien.ac.atWIEN2k: http://www.wien2k.at > WWW: http://www.imc.tuwien.ac.at > - > ___ > 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 > ___ 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
Re: [Wien] After supercell, add impurity... x sgroup change space group
It is VERY important to check which In atoms you replace by Al. View your structure and check: Did you cluster the Al on one side of the supercell ? Did you introduce a "layered" like distribution ? Most likely you want a "random" substitution, without any ordering (otherwise experiment might have found some order). Most likely, the "ideal" randomly substituted structure will even have P1 spacegroup, i.e. all symmetry operations are lost (at least for a larger supercell). PS: Experiment measures an "average structure", and therefore find a high symmetry SG. They put on the same position half a In and half a Al atom. Of course, this is not reality. Am 24.01.2021 um 21:31 schrieb Serhat Ayık: Dear Wien2k users, In my original struct file, I have (B Lattice) 3 non equiv. atoms (Chemical form: AgInS2), space group 122_I-42d, and 8 number of symmetry operations. I do 2x2x2, P lattice type supercell and I have 48 non equiv. (16 Ag, 16 In, 16 S) atoms. I want chemical form like AgAl(0.5)In(0.5)S2. I am replacing 8 In atoms with 8 Al atoms. Finally, I have 16 Ag, 8 Al, 8 In and 16 S in struct file. Then, I do - x nn (nn-bondlength factor:2) copy case.struct_nn to case.struct. (After this step, I have 7 atoms "2 Ag, 1 Al, 1 In, 3 S" in case.struct) - repeat x nn - x sgroup warning: !!! Number of inequivalent atoms has changed. !!! Old value= 48 New value= 7 warning: !!! Unit cell has been reduced. sgroup found: 17 (P 2 2 21) I think the space group shouldn't change. Is it true that the space group changes? Or am I making a mistake somewhere? Regards ___ 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 -- -- Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 Email: bl...@theochem.tuwien.ac.atWIEN2k: http://www.wien2k.at WWW: http://www.imc.tuwien.ac.at - ___ 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
Re: [Wien] After supercell, add impurity... x sgroup change space group
Depending upon how you do the replacement it is very possible that a smaller cell with a different spacegroup has been found. No indication that you are doing something wrong. Then again, you might be if you are incorrectly representing what is in experiment. That is your task to determine. _ Professor Laurence Marks "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu On Sun, Jan 24, 2021, 14:32 Serhat Ayık wrote: > Dear Wien2k users, > In my original struct file, I have (B Lattice) 3 non equiv. atoms > (Chemical form: AgInS2), space group 122_I-42d, and 8 number of symmetry > operations. > I do 2x2x2, P lattice type supercell and I have 48 non equiv. (16 Ag, 16 > In, 16 S) atoms. I want chemical form like AgAl(0.5)In(0.5)S2. I am > replacing 8 In atoms with 8 Al atoms. Finally, I have 16 Ag, 8 Al, 8 In and > 16 S in struct file. > Then, I do > - x nn (nn-bondlength factor:2) > copy case.struct_nn to case.struct. (After this step, I have 7 atoms "2 > Ag, 1 Al, 1 In, 3 S" in case.struct) > - repeat x nn > - x sgroup > warning: !!! Number of inequivalent atoms has changed. !!! Old value= 48 > New value= 7 warning: !!! Unit cell has been reduced. > sgroup found: 17 (P 2 2 21) > > I think the space group shouldn't change. > Is it true that the space group changes? Or am I making a mistake > somewhere? > > Regards > > > > > > > ___ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > > https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!F2F-jN0rxp1fNVBKZK19GJ_HXHUucrTc-Bf1BpS0c47h8WEXSU3Hs8ccvyHHLlg0oVRIRg$ > SEARCH the MAILING-LIST at: > https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!F2F-jN0rxp1fNVBKZK19GJ_HXHUucrTc-Bf1BpS0c47h8WEXSU3Hs8ccvyHHLlgGF0oFlA$ > ___ 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
[Wien] After supercell, add impurity... x sgroup change space group
Dear Wien2k users, In my original struct file, I have (B Lattice) 3 non equiv. atoms (Chemical form: AgInS2), space group 122_I-42d, and 8 number of symmetry operations. I do 2x2x2, P lattice type supercell and I have 48 non equiv. (16 Ag, 16 In, 16 S) atoms. I want chemical form like AgAl(0.5)In(0.5)S2. I am replacing 8 In atoms with 8 Al atoms. Finally, I have 16 Ag, 8 Al, 8 In and 16 S in struct file. Then, I do - x nn (nn-bondlength factor:2) copy case.struct_nn to case.struct. (After this step, I have 7 atoms "2 Ag, 1 Al, 1 In, 3 S" in case.struct) - repeat x nn - x sgroup warning: !!! Number of inequivalent atoms has changed. !!! Old value= 48 New value= 7 warning: !!! Unit cell has been reduced. sgroup found: 17 (P 2 2 21) I think the space group shouldn't change. Is it true that the space group changes? Or am I making a mistake somewhere? Regards ___ 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
