Hi, Adriano:<br><br>1) It is defined. This input was extracted from a shell script I use to run PW.<br><br>2) Is it mandatory? PW ran without any warning, though. <br><br>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?<br><br>3) It works.<br><br>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.<br><br>Regards,<br><br>Roberto<br><br><b><i>Adriano.Mosca.Conte@roma2.infn.it</i></b> wrote:<blockquote class="replbq" style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"> It seems ok apart some details:<br>1) You have to define DIR.<br>2) The cell parameters with ibrav=8 have to be specified by:<br> celldm(1)=a,celldm(2)=b/a,celldm(3)=c/a<br>3) I'm not
sure at 100% that the symbols "-" and "+" are allowed to<br>specify atomic names.<br><br>> Dear PW users:<br>><br>> I want to carry out a single point calculation of an antiferromagnetic<br>> graphene nanoribbon with PWscf. Since such a system is magnetic, with a<br>> specific magnetic orientation for the edge carbons, I have to perform a<br>> spin-polarized calculation. I'd like to know if the following PW input is<br>> suitable for such a calculation.<br>><br>> &CONTROL<br>> calculation = 'scf' ,<br>> restart_mode = 'from_scratch' ,<br>> pseudo_dir = '$DIR' ,<br>> /<br>> &SYSTEM<br>> ibrav = 8,<br>> A = 17.482046 ,<br>> B = 20.000000 ,<br>> C = 15.000000 ,<br>> nat = 70 ,<br>>
ntyp = 4,<br>> ecutwfc = 20.00 ,<br>> ecutrho = 80.00 ,<br>> occupations = 'smearing' ,<br>> degauss = 0.01 ,<br>> smearing = 'gaussian' ,<br>> nspin = 2 ,<br>> starting_magnetization(1) = -1.0 ,<br>> starting_magnetization(2) = 1.0 ,<br>> starting_magnetization(3) = 0.0 ,<br>> starting_magnetization(4) = 0.0 ,<br>> /<br>> &ELECTRONS<br>> conv_thr = 1.0D-6 ,<br>> startingpot = 'atomic',<br>> startingwfc = 'atomic',<br>> mixing_mode = 'plain' ,<br>> mixing_beta = 0.25 ,<br>> diagonalization = 'david' ,<br>> /<br>> ATOMIC_SPECIES<br>> C-1 12.0107 C.pbe.UPF<br>> C+1 12.0107 C.pbe.UPF<br>> C 12.0107
C.pbe.UPF<br>> H 1.0079 H.pbe.UPF<br>> ATOMIC_POSITIONS angstrom<br>> C+1 1.249543 -0.711074 0.000000<br>> C 0.000947 -0.016393 -0.000001<br>> C 0.000844 1.443145 -0.000001<br>> C 1.249381 2.159954 0.000001<br>> C 1.249409 3.608946 0.000001<br>> C 0.000843 4.325668 -0.000001<br>> C 0.000939 5.785283 0.000000<br>> C-1 1.249515 6.479991 -0.000001<br>> H 1.249981 -1.825631 0.000000<br>> H 1.249981 7.594413 0.000000<br>> C+1 3.746978 -0.711074 0.000000<br>> C 2.498382 -0.016393 -0.000001<br>> C 2.498279 1.443145 -0.000001<br>> C 3.746816 2.159954 0.000001<br>> C 3.746844 3.608946 0.000001<br>> C 2.498278 4.325668 -0.000001<br>> C 2.498374 5.785283 0.000000<br>> C-1 3.746950
6.479991 -0.000001<br>> H 3.747416 -1.825631 0.000000<br>> H 3.747416 7.594413 0.000000<br>> C+1 6.244413 -0.711074 0.000000<br>> C 4.995817 -0.016393 -0.000001<br>> C 4.995714 1.443145 -0.000001<br>> C 6.244251 2.159954 0.000001<br>> C 6.244279 3.608946 0.000001<br>> C 4.995713 4.325668 -0.000001<br>> C 4.995809 5.785283 0.000000<br>> C-1 6.244385 6.479991 -0.000001<br>> H 6.244851 -1.825631 0.000000<br>> H 6.244851 7.594413 0.000000<br>> C+1 8.741849 -0.711074 0.000000<br>> C 7.493253 -0.016393 -0.000001<br>> C 7.493150 1.443145 -0.000001<br>> C 8.741687 2.159954 0.000001<br>> C 8.741715 3.608946 0.000001<br>> C 7.493149 4.325668 -0.000001<br>> C 7.493245 5.785283
0.000000<br>> C-1 8.741821 6.479991 -0.000001<br>> H 8.742287 -1.825631 0.000000<br>> H 8.742287 7.594413 0.000000<br>> C+1 11.239284 -0.711074 0.000000<br>> C 9.990688 -0.016393 -0.000001<br>> C 9.990585 1.443145 -0.000001<br>> C 11.239122 2.159954 0.000001<br>> C 11.239150 3.608946 0.000001<br>> C 9.990584 4.325668 -0.000001<br>> C 9.990680 5.785283 0.000000<br>> C-1 11.239256 6.479991 -0.000001<br>> H 11.239722 -1.825631 0.000000<br>> H 11.239722 7.594413 0.000000<br>> C+1 13.736719 -0.711074 0.000000<br>> C 12.488123 -0.016393 -0.000001<br>> C 12.488020 1.443145 -0.000001<br>> C 13.736557 2.159954 0.000001<br>> C 13.736585 3.608946 0.000001<br>> C 12.488019 4.325668
-0.000001<br>> C 12.488115 5.785283 0.000000<br>> C-1 13.736691 6.479991 -0.000001<br>> H 13.737157 -1.825631 0.000000<br>> H 13.737157 7.594413 0.000000<br>> C+1 16.234154 -0.711074 0.000000<br>> C 14.985558 -0.016393 -0.000001<br>> C 14.985455 1.443145 -0.000001<br>> C 16.233992 2.159954 0.000001<br>> C 16.234020 3.608946 0.000001<br>> C 14.985454 4.325668 -0.000001<br>> C 14.985550 5.785283 0.000000<br>> C-1 16.234126 6.479991 -0.000001<br>> H 16.234592 -1.825631 0.000000<br>> H 16.234592 7.594413 0.000000<br>> K_POINTS automatic<br>> 2 1 1 0 0 0<br>><br>> Regards,<br>><br>> Roberto Veiga<br>> PhD student<br>> INSA-Lyon<br>><br>><br>> ---------------------------------<br>> Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it<br>> now._______________________________________________<br>> Pw_forum mailing list<br>> Pw_forum@pwscf.org<br>> http://www.democritos.it/mailman/listinfo/pw_forum<br>><br><br>_______________________________________________<br>Pw_forum mailing list<br>Pw_forum@pwscf.org<br>http://www.democritos.it/mailman/listinfo/pw_forum<br></blockquote><br><p> 
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