[Wien] c/a optimization
​dear wien2k users I want to run c/a optimization (constant volume) on a compound which its origin structure is cubic now i have some questions: 1- I know its cubic spacegroup but for c/a optimization in StructGen, i must create its tetragonal structure or cubic space group is correct and just changing the c parameter arbitrary? And is there any further consideration? 2- 3% Rmt reduction is enough? 3- Is there any paper to help me in details about this problem. excuse me if i ask a simple question.I am a new man. I read some papers but i was not sure about this. Thank you in advance___ 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] c/a optimization
You have to change the symmetry to tetragonal, change the c parameter by 0.001 and the program will recognize that it is not cubic. De: wien-boun...@zeus.theochem.tuwien.ac.at wien-boun...@zeus.theochem.tuwien.ac.at en nombre de Seyyed Amir Abbas Emami a.a.em...@birjand.ac.ir Enviado: lunes, 15 de junio de 2015 12:14 p. m. Para: wien@zeus.theochem.tuwien.ac.at Asunto: [Wien] c/a optimization ?dear wien2k users I want to run c/a optimization (constant volume) on a compound which its origin structure is cubic now i have some questions: 1- I know its cubic spacegroup but for c/a optimization in StructGen, i must create its tetragonal structure or cubic space group is correct and just changing the c parameter arbitrary? And is there any further consideration? 2- 3% Rmt reduction is enough? 3- Is there any paper to help me in details about this problem. excuse me if i ask a simple question.I am a new man. I read some papers but i was not sure about this. Thank you in advance ___ 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] c/a optimization error
Dear Prof Blaha and wien2k user I am doing volume optimization for a tetragonal structure. First I have done volume optimization along with force minimization.Then I am doing c/a optimization for each volume(-4,-2,0,+2,+4).While doing c/a optimization along with force minimization for -4%, -2% and 0% c/a structure,it is working fine but for +2% c/a structure it is giving this kind of error and program is stopped.This happened two times. lapw0 -p(11:13:06) starting parallel lapw0 at Wed Jan 26 11:13:06 IST 2011 .machine0 : processors running lapw0 in single mode ** lapw0 crashed! 5.880u 0.093s 0:06.08 98.1% 0+0k 0+0io 17pf+0w error: command /home1/puday/WIEN2K90/lapw0para lapw0.def failed stop error If I see the error in min.error file then it is showing STOP in MINI, FORCES small What should I do now? Any help will be highly appreciated. Regards, Uday Bhanu Paramanik Dept.of Physics IIT Kanpur India
[Wien] c/a optimization
Dear Peter Blaha Sir, should we change the indices in case.in0 to 0 0 0 and run the *c/a optimization again? *or after changing the indices what command we should give? Sir what is the meaning of *ifft parameters?* * * *Sir actually we are giving an input structure having a c/a ratio 1.25 and expecting to get a ratio of 3.75. This thing we are doing because we are giving an known structure as input and want to find the structure of a new material. This material is formed due to the replacement of one atom in A2BCO4 structure (c atom) by another atom say D and there is a material ABDO4 having c/a ratio 3.75...although it is quite possible that ABDO4 and A2BDO4 have different c/a ratioour aim is only to obtained stable c/a ratio for A2BDO4 structure. * * *with best regards, On Sat, Jul 10, 2010 at 4:27 PM, Peter Blaha pblaha at theochem.tuwien.ac.atwrote: Change the indices in case.in0 to eg. 0 0 0 (this will recalculate the required ifft parameters). However: Please THINK what you are doing ??? What is the meaning of changing c/a by factors of 3,4,5 ??? Usually you change c/a by a few percent; i.e. 3% but not 300% !!! I was doing c/a optimization for an A2BCO4 type compound. The optimize.job file was created for structures having c/a 100%, 200%, 300% and 400% increased value than the input c/a.. The program calculates structures having c/a 100% and 200% more than input c/a but stopped after that by showing the following error: 'SETFF1' - ifft too small in xcpot3 'SETFF1' - 2*(KKK+1) LARGER THAN IFFT PARAMETERS IN XCPOT3 'SETFF1' - KKK= 0 0 45 'SETFF1' - IIx= 0 0 45 'SETFF1' - IFFT= 108 96 90 I was chosen c/a value for more than 300% , 400% than the input c/a. This was done as I beliveed that the compound should have much larger c/a ratio My question is what is the meaning of this error and how to remove it. Any response will be greatly appreciated. Thanks in advance. with regards, -- Shamik Chakrabarti Research Scholar Dept. of Physics Meteorology Material Processing Solid State Ionics Lab IIT Kharagpur Kharagpur 721302 INDIA P.Blaha -- Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna Phone: +43-1-58801-15671 FAX: +43-1-58801-15698 Email: blaha at theochem.tuwien.ac.atWWW: http://info.tuwien.ac.at/theochem/ -- ___ Wien mailing list Wien at zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien -- Shamik Chakrabarti Research Scholar Dept. of Physics Meteorology Material Processing Solid State Ionics Lab IIT Kharagpur Kharagpur 721302 INDIA -- next part -- An HTML attachment was scrubbed... URL: http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20100710/b0ffc9a9/attachment.htm
