could you tell me what does the first three rows mean i saw they are all 10.d0 0.d0 0.d0 0.d0 10.d0 0.d0 0.d0 0.d0 10.d0 in your example.
and the others must be in internal crystal coordinates? Thanks! Du ?2010-04-06 05:52:51?"Matteo Cococcioni" <matteo at umn.edu> ??? > >Only atoms for which you want to compute U should be listed. >same thing in the file of positions. > >Matteo > >duchl06 wrote: >> Dear Matteo >> thanks for your quick reply, so another question as i mentioned in the >> former email. >> if we have different atoms with different number, how we set the value >> of the keyword below >> >> ntyp = 1 # number of types of atoms >> >> na(1) = 2 # number of atoms per type >> or is it only relate to the atom with a nonzero U value. >> best regards! >> du >> >> ?2010-04-05 21:48:59?"Matteo Cococcioni" <matteo at umn.edu> ??? >> > >> >Dear Du, >> > >> >the input you found below is to extract the U values from a series of >> >scf calculations. >> >You can give a look (besides the reference cited below) to the tutorials >> >you find in this webpage: >> >http://www.quantum-espresso.org/wiki/index.php/QESB09. >> >Unfrtunately the value of U is generally not portable and changes >> >depending on the invironment of the atom in the >> >specific crystal you are considering. the one you cite is a good >> >example: Fe in bulk Fe and in FeO. >> >So in principles we need to recompute it each time. >> > >> >hope this helps. >> > >> >Matteo >> > >> > >> >duchl06 wrote: >> >> dear pw users >> >> i want to do a calculation of V chain absorb on a plane with DFT+U, >> >> but i donot know how to determine the value of U. >> >> i found a PPT on the pwscf's media site, they said the value of U >> >> could be decised by a linear response approach. >> >> but i really donot understand that like the input file resp_mat.in >> >> >> >> &input_mat >> >> ntyp = 1 # number of types of atoms >> >> na(1) = 2 # number of atoms per type >> >> if we have different type atoms with different number, how we set these? >> >> >> >> nalfa = 5 # number of perturbations (alpha) >> >> filepos = 'pos_sc1' # file containing the atomic positions and the >> >> vectors of the unit cell >> >> back = 'neutral' # to add a neutralizing ?background?. see PRB 71 >> >> 35105 (2005) >> >> what does this mean >> >> filednda = 'file_sc1' # file containing the names of the files dn*dat >> >> n1 = 4 >> >> n2 = 4 # number of unit cells in each direction to construct the >> >> supercell for >> >> n3 = 4 # extrapolation (in this case a 4x4x4 supercell of the SC one) >> >> &end >> >> >> >> and they get the U is about 2.4ev for the iron, and they use 4.3ev for >> >> the FeO calculation, >> >> we always need a linear response approach to get the U for every system >> >> or just a U for a certain pseudopotential (i mean if we get a U for V >> >> bulk, then if i could use this value for another system with V atom, >> >> like V2O3 etc.) >> >> any suggestions or comment would be OK. >> >> thanks >> >> >> >> Du >> >> xiaguanying university >> >> >> >> >> >> ------------------------------------------------------------------------ >> >> >> >> _______________________________________________ >> >> Pw_forum mailing list >> >> Pw_forum at pwscf.org >> >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> >> > >> >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> > > >-- >%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% >Matteo Cococcioni >Department of Chemical Engineering and Materials Science, >University of Minnesota >421 Washington Av. SE >Minneapolis, MN 55455 >Tel. +1 612 624 9056 Fax +1 612 626 7246 >%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100406/a98a6e20/attachment.htm
