I guess an easy yet efficient way for generating your alloy structure is to use the Monte Carlo SQS (mcsqs) module which is part of the ATAT gnu software available from: https://www.brown.edu/Departments/Engineering/Labs/avdw/atat/
M A H Khalafalla Taibah University Dept of Physics On Friday, October 7, 2016, Krishnaiah Kallamadi <[email protected]> wrote: > Dear Sir, > > Thanks a lot > > On Fri, Oct 7, 2016 at 7:05 PM, Michael Mehl <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > >> [image: Boxbe] <https://www.boxbe.com/overview> This message is eligible >> for Automatic Cleanup! ([email protected] >> <javascript:_e(%7B%7D,'cvml','[email protected]');>) Add cleanup rule >> <https://www.boxbe.com/popup?url=https%3A%2F%2Fwww.boxbe.com%2Fcleanup%3Fkey%3DLVHND7MjoxgBGakvoZQT7xZ3O%252F3rDX1smiXxAj6N%252BEo%253D%26token%3DqwPCh8a31O8xLW2%252F35HfKg6%252BmSXIoOED7nnworLV2ruO57Qj7LbuGAMAMDY1cD%252BVoByPdkzPVI9TKCFZ9OKIzvVvb2c12J0dzVL4DAcgLREEXbt3%252FV4KtUlXmkzHwSlHBHYWlCBBdfg%253D&tc_serial=27078230358&tc_rand=502960097&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001> >> | More info >> <http://blog.boxbe.com/general/boxbe-automatic-cleanup?tc_serial=27078230358&tc_rand=502960097&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001> >> >> Since C and N are neighbors in the periodic table, you could put a >> "virtual" atom at the site, with charge Z = 6.5. That would at least give >> you the right electron count for the system and preserve the system >> symmetry. The downside is that a pseudopotential for "Cargen" or >> "Nitrobon" probably doesn't exist, so you'd have to generate it yourself. >> I think VASP is able to handle this somehow, but I've never tried it. >> >> Another alternative is to generate a supercell, randomly populate that >> site with C and N atoms, and average over configurations. Look up various >> articles by Alex Zunger et al. (http://journals.aps.org/prl/a >> bstract/10.1103/PhysRevLett.65.353, to start) on Special Quasirandom >> Structures for some hints on how to do this efficiently. The downside of >> this is that you'll need a fair number of structures, and you'll lose the >> hexagonal symmetry in the individual calculations. >> >> AFAIK, there aren't any really good solutions for this problem with the >> current generation of DFT codes. At one time there was some work with the >> Coherent Potential Approximation and KKR (see http://journals.aps.org/p >> rb/pdf/10.1103/PhysRevB.67.115109, e.g.), but I don't think any modern >> KKR codes are easily available, much less KKR+CPA. >> >> On Fri, Oct 7, 2016 at 7:50 AM, Krishnaiah Kallamadi < >> [email protected] >> <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: >> >>> As per my knowledge, >>> espresso can't deal with above cif file. Please help me and correct if I >>> am wrong. >>> >>> On Fri, Oct 7, 2016 at 11:33 AM, Andrius Merkys < >>> [email protected] >>> <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: >>> >>>> [image: Boxbe] <https://www.boxbe.com/overview> This message is >>>> eligible for Automatic Cleanup! ([email protected] >>>> <javascript:_e(%7B%7D,'cvml','[email protected]');>) Add >>>> cleanup rule >>>> <https://www.boxbe.com/popup?url=https%3A%2F%2Fwww.boxbe.com%2Fcleanup%3Fkey%3DXwuYbtQTWmfZGZsFKbO6InxZfjQtGSxrL%252FwuVJ%252FUXAE%253D%26token%3DJUW0Wts7GmUB4X1qCEMY8jvGAd0zfkPK1lTr9NzQRQI0yaxZFlH1MMfBGJfWwNxAn9vrVh0QLSJUWizBuQx1RH1a7mw3Iol2zUDxjiWVehZ%252Bx2PzIhsM%252FIEhy78t1KraT3iv3nEj9prEPJ0yaqyzmA%253D%253D&tc_serial=27072627350&tc_rand=1012971690&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001> >>>> | More info >>>> <http://blog.boxbe.com/general/boxbe-automatic-cleanup?tc_serial=27072627350&tc_rand=1012971690&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001> >>>> >>>> Dear Krishna, >>>> >>>> On 07/10/16 08:30, Krishnaiah Kallamadi wrote: >>>> >>>> In a *cif* file attached below, two different atoms have same atomic >>>> positions with occupancy of 0.5. Due to this i am not able to generate >>>> *scf.in >>>> <http://scf.in>* file from cif2cell program. Please help me. >>>> >>>> >>>> you have to account for a joint 0.5N+0.5C site at this position. I am >>>> not sure if/how such thing is possible at QE input, but AFAIK, people are >>>> dealing with such models. >>>> >>>> HTH, >>>> Andrius >>>> >>>> -- >>>> Andrius Merkys >>>> PhD student at Vilnius University Institute of Biotechnology, SaulÄ—tekio >>>> al. 7 >>>> LT-10223 Vilnius, Lithuania >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> >>>> http://pwscf.org/mailman/listinfo/pw_forum >>>> >>>> >>> >>> >>> -- >>> Thanks and Regards, >>> >>> K.Krishna >>> JRF, AcSIR-RE >>> CSIR-SERC >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> >>> http://pwscf.org/mailman/listinfo/pw_forum >>> >> >> >> >> -- >> >> [image: USNA_Gold_Seal.png] >> >> Michael J. Mehl, Ph.D. >> >> Kinnear Chair in Physics >> >> The United States Naval Academy >> >> Mail Stop 9C >> >> 572 Holloway Road >> >> Chauvenet Hall 257 >> >> Annapolis MD 21402 >> >> (410)293-6685 >> >> [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> >> http://pwscf.org/mailman/listinfo/pw_forum >> >> > > > -- > Thanks and Regards, > > K.Krishna > JRF, AcSIR-RE > CSIR-SERC > -- Sent from Gmail Mobile
_______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
