Hi, Adriano: 1) It is defined. This input was extracted from a shell script I use to run PW.
2) Is it mandatory? PW ran without any warning, though. What I wanted is to define a chain, that is, it is periodic only along x direction. y and z are just large enough to prevent spurious interactions with the ribbon images. Is there another (better) way to specify the cell parameters for such a system? 3) It works. I already ran this input, but I was not sure if the system (a narrow graphene ribbon -- a chain -- with magnetic edges) had been defined correctly. Regards, Roberto Adriano.Mosca.Conte at roma2.infn.it wrote: It seems ok apart some details: 1) You have to define DIR. 2) The cell parameters with ibrav=8 have to be specified by: celldm(1)=a,celldm(2)=b/a,celldm(3)=c/a 3) I'm not sure at 100% that the symbols "-" and "+" are allowed to specify atomic names. > Dear PW users: > > I want to carry out a single point calculation of an antiferromagnetic > graphene nanoribbon with PWscf. Since such a system is magnetic, with a > specific magnetic orientation for the edge carbons, I have to perform a > spin-polarized calculation. I'd like to know if the following PW input is > suitable for such a calculation. > > &CONTROL > calculation = 'scf' , > restart_mode = 'from_scratch' , > pseudo_dir = '$DIR' , > / > &SYSTEM > ibrav = 8, > A = 17.482046 , > B = 20.000000 , > C = 15.000000 , > nat = 70 , > ntyp = 4, > ecutwfc = 20.00 , > ecutrho = 80.00 , > occupations = 'smearing' , > degauss = 0.01 , > smearing = 'gaussian' , > nspin = 2 , > starting_magnetization(1) = -1.0 , > starting_magnetization(2) = 1.0 , > starting_magnetization(3) = 0.0 , > starting_magnetization(4) = 0.0 , > / > &ELECTRONS > conv_thr = 1.0D-6 , > startingpot = 'atomic', > startingwfc = 'atomic', > mixing_mode = 'plain' , > mixing_beta = 0.25 , > diagonalization = 'david' , > / > ATOMIC_SPECIES > C-1 12.0107 C.pbe.UPF > C+1 12.0107 C.pbe.UPF > C 12.0107 C.pbe.UPF > H 1.0079 H.pbe.UPF > ATOMIC_POSITIONS angstrom > C+1 1.249543 -0.711074 0.000000 > C 0.000947 -0.016393 -0.000001 > C 0.000844 1.443145 -0.000001 > C 1.249381 2.159954 0.000001 > C 1.249409 3.608946 0.000001 > C 0.000843 4.325668 -0.000001 > C 0.000939 5.785283 0.000000 > C-1 1.249515 6.479991 -0.000001 > H 1.249981 -1.825631 0.000000 > H 1.249981 7.594413 0.000000 > C+1 3.746978 -0.711074 0.000000 > C 2.498382 -0.016393 -0.000001 > C 2.498279 1.443145 -0.000001 > C 3.746816 2.159954 0.000001 > C 3.746844 3.608946 0.000001 > C 2.498278 4.325668 -0.000001 > C 2.498374 5.785283 0.000000 > C-1 3.746950 6.479991 -0.000001 > H 3.747416 -1.825631 0.000000 > H 3.747416 7.594413 0.000000 > C+1 6.244413 -0.711074 0.000000 > C 4.995817 -0.016393 -0.000001 > C 4.995714 1.443145 -0.000001 > C 6.244251 2.159954 0.000001 > C 6.244279 3.608946 0.000001 > C 4.995713 4.325668 -0.000001 > C 4.995809 5.785283 0.000000 > C-1 6.244385 6.479991 -0.000001 > H 6.244851 -1.825631 0.000000 > H 6.244851 7.594413 0.000000 > C+1 8.741849 -0.711074 0.000000 > C 7.493253 -0.016393 -0.000001 > C 7.493150 1.443145 -0.000001 > C 8.741687 2.159954 0.000001 > C 8.741715 3.608946 0.000001 > C 7.493149 4.325668 -0.000001 > C 7.493245 5.785283 0.000000 > C-1 8.741821 6.479991 -0.000001 > H 8.742287 -1.825631 0.000000 > H 8.742287 7.594413 0.000000 > C+1 11.239284 -0.711074 0.000000 > C 9.990688 -0.016393 -0.000001 > C 9.990585 1.443145 -0.000001 > C 11.239122 2.159954 0.000001 > C 11.239150 3.608946 0.000001 > C 9.990584 4.325668 -0.000001 > C 9.990680 5.785283 0.000000 > C-1 11.239256 6.479991 -0.000001 > H 11.239722 -1.825631 0.000000 > H 11.239722 7.594413 0.000000 > C+1 13.736719 -0.711074 0.000000 > C 12.488123 -0.016393 -0.000001 > C 12.488020 1.443145 -0.000001 > C 13.736557 2.159954 0.000001 > C 13.736585 3.608946 0.000001 > C 12.488019 4.325668 -0.000001 > C 12.488115 5.785283 0.000000 > C-1 13.736691 6.479991 -0.000001 > H 13.737157 -1.825631 0.000000 > H 13.737157 7.594413 0.000000 > C+1 16.234154 -0.711074 0.000000 > C 14.985558 -0.016393 -0.000001 > C 14.985455 1.443145 -0.000001 > C 16.233992 2.159954 0.000001 > C 16.234020 3.608946 0.000001 > C 14.985454 4.325668 -0.000001 > C 14.985550 5.785283 0.000000 > C-1 16.234126 6.479991 -0.000001 > H 16.234592 -1.825631 0.000000 > H 16.234592 7.594413 0.000000 > K_POINTS automatic > 2 1 1 0 0 0 > > Regards, > > Roberto Veiga > PhD student > INSA-Lyon > > > --------------------------------- > Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it > now._______________________________________________ > 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 --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080509/71deaa06/attachment.htm
