Hello, Il giorno 28/lug/2011, alle ore 23.03, chengyu yang ha scritto:
> Dear All, > I am trying to calculate the complex bands and the transmission of a > (5,5) defectless carbon nanotube using PWCOND.x, however, the calculation > process is very slow and I can see it kind of stopped at the point: ngper, > shell number = 2809 299. Your value of ngper is quite large for this kind of calculations, you can't afford it without using a lot of processors in a parallel calculation. Moreover, as far as I know the calculation of the complex bands is not completely parallelized at the moment, hence if your leads have a very large cross section and contain really a lot of atoms, I'm afraid that the calculation is hardly feasible with the current implementation. In your case, the calculation should be feasible with 8-16 processors in parallel (if nodes have enough memory), but only if you use USPP, so that you will be able to reduce the ecutwfc down to 30-35 Ry. In the PWcond input file I would reduce epsproj to 10^-5 or 10^-6, depending on the level of accuracy required (but you should do a small test on this). HTH GS > My input files are like this: > > > ################################################################################## > scf input file: > > &CONTROL > calculation = 'scf' , > restart_mode = 'from_scratch' , > prefix = '55' , > / > &SYSTEM > ibrav = 6, > celldm(1) = 21.764541128,celldm(3)=0.213765379 > nat = 20, > ntyp = 1, > ecutwfc = 75 , > / > &ELECTRONS > conv_thr = 1.0d-8 , > mixing_beta = 0.7 , > / > ATOMIC_SPECIES > C 12.01100 C.pz-vbc.UPF > > ATOMIC_POSITIONS angstrom > > C 3.409595 0.000000 -1.231179 > C 3.113484 1.389805 -1.231179 > C 2.758420 2.004110 -0.000000 > C 1.701954 2.954436 -0.000000 > C 1.053623 3.242718 -1.231179 > C -0.359664 3.390572 -1.231179 > C -1.053623 3.242718 -0.000000 > C -2.283903 2.531625 -0.000000 > C -2.758420 2.004110 -1.231179 > C -3.335768 0.705684 -1.231179 > C -3.409595 0.000000 -0.000000 > C -3.113484 -1.389805 -0.000000 > C -2.758420 -2.004110 -1.231179 > C -1.701954 -2.954436 -1.231179 > C -1.053623 -3.242718 0.000000 > C 0.359664 -3.390572 0.000000 > C 1.053623 -3.242718 -1.231179 > C 2.283903 -2.531625 -1.231179 > C 2.758420 -2.004110 0.000000 > C 3.335768 -0.705684 0.000000 > > > > > K_POINTS automatic > 1 1 5 0 0 0 > > > ############################################################################### > > pwcond.in file: > > > &inputcond > prefixl='55' > band_file ='bands.cnt55' > ikind=0 > energy0=4.d0 > denergy=-0.1d0 > ewind=3.d0 > epsproj=1.d-4 > delgep = 1.d-9 > cutplot = 3.d0 > / > 1 > 0.0 0.0 1.0 > 5 > > ########################################################### > and the output file: > > GEOMETRY: > > lattice parameter (a_0) = 21.7645 a.u. > the volume = 2203.8697 (a.u.)^3 > the cross section = 473.6953 (a.u.)^2 > l of the unit cell = 0.2138 (a_0) > number of atoms/cell = 20 > number of atomic types = 1 > > crystal axes: (cart. coord. in units of a_0) > a(1) = ( 1.0000 0.0000 0.0000 ) > a(2) = ( 0.0000 1.0000 0.0000 ) > a(3) = ( 0.0000 0.0000 0.2138 ) > > > Cartesian axes > > site n. atom positions (a_0 units) > 1 C tau( 1)=( 0.2960 0.0000 0.1069 ) > 2 C tau( 2)=( 0.2703 0.1207 0.1069 ) > 3 C tau( 3)=( 0.2395 0.1740 0.2138 ) > 4 C tau( 4)=( 0.1478 0.2565 0.2138 ) > 5 C tau( 5)=( 0.0915 0.2816 0.1069 ) > 6 C tau( 6)=( -0.0312 0.2944 0.1069 ) > 7 C tau( 7)=( -0.0915 0.2816 0.2138 ) > 8 C tau( 8)=( -0.1983 0.2198 0.2138 ) > 9 C tau( 9)=( -0.2395 0.1740 0.1069 ) > 10 C tau( 10)=( -0.2896 0.0613 0.1069 ) > 11 C tau( 11)=( -0.2960 0.0000 0.2138 ) > 12 C tau( 12)=( -0.2703 -0.1207 0.2138 ) > 13 C tau( 13)=( -0.2395 -0.1740 0.1069 ) > 14 C tau( 14)=( -0.1478 -0.2565 0.1069 ) > 15 C tau( 15)=( -0.0915 -0.2816 0.2138 ) > 16 C tau( 16)=( 0.0312 -0.2944 0.2138 ) > 17 C tau( 17)=( 0.0915 -0.2816 0.1069 ) > 18 C tau( 18)=( 0.1983 -0.2198 0.1069 ) > 19 C tau( 19)=( 0.2395 -0.1740 0.2138 ) > 20 C tau( 20)=( 0.2896 -0.0613 0.2138 ) > > nr1s = 120 > nr2s = 120 > nr3s = 27 > nrx1s = 120 > nrx2s = 120 > nrx3s = 27 > nr1 = 120 > nr2 = 120 > nr3 = 27 > nrx1 = 120 > nrx2 = 120 > nrx3 = 27 > > _______________________________ > Radii of nonlocal spheres: > > type ibeta ang. mom. radius (a_0 units) > C 1 0 0.0593 > ----- General information ----- > > ----- Complex band structure calculation ----- > > nrx = 120 > nry = 120 > nz1 = 11 > > > energy0 = 4.0E+00 > denergy = -1.0E-01 > nenergy = 5 > ecut2d = 7.5E+01 > ewind = 3.0E+00 > epsproj = 1.0E-04 > > > number of k_|| points= 1 > cryst. coord. > k( 1) = ( 0.0000000 0.0000000), wk = 1.0000000 > ----- Information about left lead ----- > > nocros = 10 > noins = 10 > norb = 30 > norbf = 30 > nrz = 27 > > iorb type ibeta ang. mom. m position (a_0) > 1 1 1 0 1 taunew( 1)=( 0.2395 0.1740 > 0.0000) > 2 1 1 0 1 taunew( 2)=( 0.1478 0.2565 > 0.0000) > 3 1 1 0 1 taunew( 3)=( -0.0915 0.2816 > 0.0000) > 4 1 1 0 1 taunew( 4)=( -0.1983 0.2198 > 0.0000) > 5 1 1 0 1 taunew( 5)=( -0.2960 0.0000 > 0.0000) > 6 1 1 0 1 taunew( 6)=( -0.2703 -0.1207 > 0.0000) > 7 1 1 0 1 taunew( 7)=( -0.0915 -0.2816 > 0.0000) > 8 1 1 0 1 taunew( 8)=( 0.0312 -0.2944 > 0.0000) > 9 1 1 0 1 taunew( 9)=( 0.2395 -0.1740 > 0.0000) > 10 1 1 0 1 taunew( 10)=( 0.2896 -0.0613 > 0.0000) > 11 1 1 0 1 taunew( 11)=( 0.2960 0.0000 > 0.1069) > 12 1 1 0 1 taunew( 12)=( 0.2703 0.1207 > 0.1069) > 13 1 1 0 1 taunew( 13)=( 0.0915 0.2816 > 0.1069) > 14 1 1 0 1 taunew( 14)=( -0.0312 0.2944 > 0.1069) > 15 1 1 0 1 taunew( 15)=( -0.2395 0.1740 > 0.1069) > 16 1 1 0 1 taunew( 16)=( -0.2896 0.0613 > 0.1069) > 17 1 1 0 1 taunew( 17)=( -0.2395 -0.1740 > 0.1069) > 18 1 1 0 1 taunew( 18)=( -0.1478 -0.2565 > 0.1069) > 19 1 1 0 1 taunew( 19)=( 0.0915 -0.2816 > 0.1069) > 20 1 1 0 1 taunew( 20)=( 0.1983 -0.2198 > 0.1069) > 21 1 1 0 1 taunew( 21)=( 0.2395 0.1740 > 0.2138) > 22 1 1 0 1 taunew( 22)=( 0.1478 0.2565 > 0.2138) > 23 1 1 0 1 taunew( 23)=( -0.0915 0.2816 > 0.2138) > 24 1 1 0 1 taunew( 24)=( -0.1983 0.2198 > 0.2138) > 25 1 1 0 1 taunew( 25)=( -0.2960 0.0000 > 0.2138) > 26 1 1 0 1 taunew( 26)=( -0.2703 -0.1207 > 0.2138) > 27 1 1 0 1 taunew( 27)=( -0.0915 -0.2816 > 0.2138) > 28 1 1 0 1 taunew( 28)=( 0.0312 -0.2944 > 0.2138) > 29 1 1 0 1 taunew( 29)=( 0.2395 -0.1740 > 0.2138) > 30 1 1 0 1 taunew( 30)=( 0.2896 -0.0613 > 0.2138) > k slab z(k) z(k+1) crossing(iorb=1,norb) > 1 0.0000 0.0079 0.0079 111111111100000000000000000000 > 2 0.0079 0.0158 0.0079 111111111100000000000000000000 > 3 0.0158 0.0238 0.0079 111111111100000000000000000000 > 4 0.0238 0.0317 0.0079 111111111100000000000000000000 > 5 0.0317 0.0396 0.0079 111111111100000000000000000000 > 6 0.0396 0.0475 0.0079 111111111100000000000000000000 > 7 0.0475 0.0554 0.0079 111111111111111111110000000000 > 8 0.0554 0.0633 0.0079 111111111111111111110000000000 > 9 0.0633 0.0713 0.0079 000000000011111111110000000000 > 10 0.0713 0.0792 0.0079 000000000011111111110000000000 > 11 0.0792 0.0871 0.0079 000000000011111111110000000000 > 12 0.0871 0.0950 0.0079 000000000011111111110000000000 > 13 0.0950 0.1029 0.0079 000000000011111111110000000000 > 14 0.1029 0.1108 0.0079 000000000011111111110000000000 > 15 0.1108 0.1188 0.0079 000000000011111111110000000000 > 16 0.1188 0.1267 0.0079 000000000011111111110000000000 > 17 0.1267 0.1346 0.0079 000000000011111111110000000000 > 18 0.1346 0.1425 0.0079 000000000011111111110000000000 > 19 0.1425 0.1504 0.0079 000000000011111111110000000000 > 20 0.1504 0.1583 0.0079 000000000011111111111111111111 > 21 0.1583 0.1663 0.0079 000000000011111111111111111111 > 22 0.1663 0.1742 0.0079 000000000000000000001111111111 > 23 0.1742 0.1821 0.0079 000000000000000000001111111111 > 24 0.1821 0.1900 0.0079 000000000000000000001111111111 > 25 0.1900 0.1979 0.0079 000000000000000000001111111111 > 26 0.1979 0.2058 0.0079 000000000000000000001111111111 > 27 0.2058 0.2138 0.0079 000000000000000000001111111111 > > k( 1) = ( 0.0000000 0.0000000), wk = 1.0000000 > > ngper, shell number = 2809 299 > #################################################################################### > the output file stopped there, and I couldn't see the process. Maybe it > takes long time cause I found it took 1 hour to calculate a transmission. > I don't quite understand the parameters setting, I have adjusted the ewind, > epsproj, nzl, according to the postings on this forum. However, > the result seemed not change. > > I appreciate everyone who could give me some advice. > Thank you! > > Regards. > > Chengyu Yang > Material Science and Engineering, > University of Central Florida, USA > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum ? Gabriele Sclauzero, EPFL SB ITP CSEA PH H2 462, Station 3, CH-1015 Lausanne -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110802/08ce46bf/attachment-0001.htm
