---------- Forwarded message ---------- From: shamik chakrabarti <shamik...@gmail.com> Date: Sat, Jul 10, 2010 at 5:09 PM Subject: Re: [Wien] c/a optimization To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
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 ratio....our 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.at>wrote: > 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.at WWW: > 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 -- 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/20100712/60564fe7/attachment.htm>