Really appreciate last two responses. Thank you both of you Sir. Everyone helped me on many occasions. I am grateful to all of you.
Best regards Naseem On Fri, Jul 4, 2014 at 3:04 PM, Michael Sluydts <michael.sluy...@ugent.be> wrote: > Hello Naseem, > > The problem you have is a lack of information. The spacegroup and > stoichiometry still give you freedom through wyckoff positions to create a > variety of structures. > > There are multiple avenues you can take. The first is to search the > literature and databases (COD: http://www.crystallography.net and ICSD if > you have access to it http://www.fiz-karlsruhe.com/icsd_home.html), > though I did not immediately find anything of interest in COD. If you > cannot find the structure then it becomes a different problem, rather than > determining materials properties you will have to do structure prediction. > > Structure prediction is a discipline in itself (literature available) and > can take a lot of time. If you know of similar compounds you may be able to > base yourself on them as a starting point to reduce your search space, then > try a few different configurations for the atoms, optimize your cells and > see what is lowest in energy. > > Other more advanced methods are things like genetic algorithms where you > try different structures then combine them and gradually converge to a > candidate for the optimal structure. Software like USPEX exists for this > but I don't think it has been used with wien2k, though interfacing with it > should not be entirely impossible. > > Trying to get more details on what you might be looking for is going to be > the first step either way. > > > Good luck, > > Michael Sluydts > > > > Naseem Hassan schreef op 4/07/2014 11:53: > > Thank You All. > > I benefited from all of you on mailing list. You are absolutely right I > should learn instead of spoon feeding. I can understand fully that experts > are already handling the burden of below average questions. > > Inspite of all your recommendation I wish that someone should suggest a > road map of topics that leads to solution of making new structure in > WIEN2k. I see many emails on mailing list that suggest the similar kind of > problem of making structure for a specific space group. I really wanted to > learn this but always lost in multiple topics. Many of seniors to whom I > know personally know can not solve this problem. Just suggesting, that it > will beneficial for newcomers if someone can prepare a tutorial on this > issue. We sometimes do not work on compounds just because we cannot make > structure file in wien2k. > > Best Regards > Naseem > > > > On Fri, Jul 4, 2014 at 1:16 PM, Juan Manuel Perez Mato <wmppe...@lg.ehu.es > > wrote: > >> Please, learn some elementary crystallography in the International year >> of crystallography. >> >> regards, >> >> J. Manuel Perez-Mato >> Fac. Ciencia y Tecnologia, >> Universidad del Pais Vasco, UPV >> 48080 BILBAO, >> Spain >> >> tel. +34 946012473 <%2B34%20946012473> >> fax. +34 946013500 <%2B34%20946013500> >> *************************************************** >> >> El 04/07/2014, a las 02:37, Naseem Hassan escribió: >> >> Dear Sir, >> >> Every space group has some ideal positions. From little experience in >> the past, I believe on selecting 3 atoms in the start of structure >> generation and assigning positions for three atoms will give the primitive >> cell for this space group. In this primitive cell other positions appear >> automatically by Wien2k. Does a space group has not ideal positions ?. I >> need ideal positions for three atoms and then I will relax the structure to >> actual positions for this compound. Modeling a material is possible without >> experimental results. I am hopeful that you will propose some kind of >> solution. >> >> Thank you >> Best Regards >> Naseem Hassan >> >> >> >> >> On Fri, Jul 4, 2014 at 1:22 AM, Peter Blaha <pbl...@theochem.tuwien.ac.at >> > wrote: >> >>> Without atomic positions one cannot create a structure. >>> >>> Am 03.07.2014 19:46, schrieb Naseem Hassan: >>> >>>> Dear Wien2k experts >>>> >>>> I am reporting this difficulty after going through mailing list and >>>> literature review. Kindly guide how can I generate structure file with >>>> the following information. >>>> >>>> Compound Formula: V3S7Cl >>>> Space Group: C mmm#65 Orthorhombic >>>> lattice parameters: a=20.6 b=3.8, c=3.9 >>>> >>>> I need *general structure file* for this compound I will try to remove >>>> error associated with RMTs and other initializing parameters by my self. >>>> >>>> Alternatively, >>>> >>>> If I select 3 atoms in the structure generation and I insert all the >>>> parameters as stated above then I just miss the position of three atoms >>>> in the structure file. In order to fill the positions I checked the >>>> wycoff psoitions from the Bilbao Crystallographic server but I am unable >>>> to understand which position should I give. *If this approach is >>>> correct* then kindly just *provide the positions* which I can fill at >>>> least ideal positions for this kind of space group so that I can fill >>>> and later on I will relax my structure to get actual positons. Kindly do >>>> guide. >>>> >>>> Best Regards >>>> Naseem Hassan >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> 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.Materials Chemistry >>> TU Vienna >>> Getreidemarkt 9 >>> A-1060 Vienna >>> Austria >>> +43-1-5880115671 >>> _______________________________________________ >>> 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 >> >> >> >> >> _______________________________________________ >> 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 > listw...@zeus.theochem.tuwien.ac.athttp://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 > >
_______________________________________________ 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