Dear colleagues, I am beginner user of the Quantum-Espresso. My task is the simulation 32 water molecules (H2O). I have still some problems. The main of them is a variable-cell MD with cp.x code under constantly high pressure in the (NpT - ensemble). Another words, I am exploring 32 molecules of water under high pressure and specific temperature. My script to this case is
# Electronical + Ionic Dynamics + NOSE thermostat on ions + &CONTROL title = ' Water 32 Molecules ', calculation = 'vc-cp', restart_mode = 'restart', ndr = 51, ndw = 52, nstep = 2000, iprint = 10, isave = 10, tstress = .TRUE., tprnfor = .TRUE., dt = 4.0d0, etot_conv_thr = 1.d-9, ekin_conv_thr = 1.d-4, prefix = 'h2o_mol' pseudo_dir = './pseudo/' outdir = './tmp/' / &SYSTEM ibrav = 14, celldm(1) = 18.65, celldm(2) = 1.0, celldm(3) = 1.0, celldm(4) = 0.0, celldm(5) = 0.0, celldm(6) = 0.0, nat = 96, ntyp = 2, nbnd = 128, nelec = 256, ecutwfc = 70.0, ecfixed = 68.0, qcutz = 68.0, q2sigma = 8.0, xc_type = 'BLYP', / &ELECTRONS emass = 300.d0, emass_cutoff = 2.5d0, orthogonalization = 'ortho', electron_dynamics = 'verlet', electron_velocities = 'zero', ortho_eps = 5.d-8, ortho_max = 15, / &IONS ion_dynamics = 'verlet', ion_temperature = 'nose', !ion_velocities = 'zero', tempw = 277.0, fnosep = 48, ion_radius(1) = 0.8d0, ion_radius(2) = 0.5d0, / &CELL cell_dynamics = 'pr', !cell_velocities = 'zero', press = 0.2d0, wmass = 79859.24 / ATOMIC_SPECIES O 16.0d0 O.BLYP.UPF 4 H 1.0079d0 H.fpmd.UPF 4 ATOMIC_POSITIONS (crystal) !(bohr) O 0.3342 0.3858 0.1702 O 0.6681 0.0772 0.0996 O 0.4894 0.2752 0.9664 O 0.8374 0.0165 0.8885 O 0.4164 0.1406 0.5374 O 0.9200 0.2746 0.7479 O 0.9298 0.6759 0.0546 O 0.5197 0.5773 0.2470 O 0.8453 0.2308 0.2531 O 0.7080 0.4512 0.1102 O 0.6297 0.6739 0.4697 O 0.6889 0.4428 0.8100 O 0.9273 0.8859 0.2748 O 0.7260 0.9572 0.4514 O 0.9539 0.6297 0.6304 O 0.0634 0.4197 0.2665 O 0.0088 0.1409 0.5073 O 0.8042 0.4375 0.4942 O 0.6981 0.1893 0.5833 O 0.2908 0.5198 0.5234 O 0.1835 0.3971 0.7808 O 0.2450 0.2024 0.3474 O 0.3062 0.1574 0.7995 O 0.4465 0.8389 0.2161 O 0.1931 0.5738 0.0049 O 0.1879 0.9665 0.1899 O 0.0876 0.6667 0.4085 O 0.2637 0.7476 0.7879 O 0.5203 0.6329 0.7214 O 0.3714 0.8763 0.4899 O 0.7915 0.8290 0.7054 O 0.1436 0.9899 0.9297 H 0.3742 0.3360 0.0929 H 0.3150 0.3226 0.2472 H 0.9405 0.1804 0.4516 H 0.6062 0.0086 0.1372 H 0.7231 0.0354 0.0264 H 0.5460 0.2002 0.9884 H 0.5502 0.3269 0.9029 H 0.8537 0.1049 0.8480 H 0.4251 0.0432 0.5210 H 0.3722 0.1543 0.6275 H 0.7041 0.0486 0.4909 H 0.9378 0.2191 0.6620 H 0.9083 0.7339 0.1314 H 0.5940 0.5403 0.1919 H 0.4413 0.5140 0.2303 H 0.7975 0.1623 0.1939 H 0.9351 0.2490 0.2169 H 0.7495 0.3794 0.1764 H 0.7769 0.5261 0.0949 H 0.7242 0.6488 0.4514 H 0.5812 0.6156 0.4033 H 0.7610 0.3991 0.7586 H 0.7253 0.4549 0.9012 H 0.9805 0.8118 0.3158 H 0.8774 0.9234 0.3508 H 0.8266 0.9432 0.8185 H 0.6439 0.9054 0.4658 H 0.9099 0.7082 0.6739 H 0.1146 0.3475 0.3129 H 0.1177 0.4592 0.1936 H 0.0984 0.1864 0.4941 H 0.8732 0.4903 0.5432 H 0.8466 0.4047 0.4105 H 0.5983 0.1849 0.5758 H 0.7255 0.2866 0.5619 H 0.2468 0.6010 0.4948 H 0.3655 0.5512 0.5766 H 0.2218 0.4478 0.6984 H 0.2272 0.3027 0.7736 H 0.0089 0.3172 0.7749 H 0.3206 0.1756 0.4126 H 0.2308 0.1250 0.2800 H 0.2420 0.1027 0.8550 H 0.3752 0.1963 0.8703 H 0.3477 0.8559 0.1901 H 0.4738 0.7418 0.2103 H 0.0297 0.6626 0.0605 H 0.2668 0.5360 0.0599 H 0.1691 0.9883 0.0958 H 0.0952 0.9378 0.2237 H 0.0161 0.6488 0.4768 H 0.0940 0.5739 0.3729 H 0.2728 0.6995 0.8762 H 0.3551 0.7479 0.7517 H 0.5812 0.5576 0.7579 H 0.5605 0.6617 0.6349 H 0.1741 0.5139 0.9284 H 0.3026 0.8058 0.5084 H 0.4067 0.8573 0.3940 H 0.7040 0.7965 0.7365 H 0.7716 0.8608 0.6097 H 0.0148 0.6043 0.7064 H 0.1834 0.9112 0.8662 H 0.0492 0.9894 0.9207 KSOUT 2 1 4 this is 7 step, when the system is relaxing and there is the electron and ion dynamics and then at the 7 step I have adding the pressure on system. The value for "wmass" in CELL section I got from the previous step. During the calculation I have one problem: in the step7.out file the value of (XNHH0 - position of Nose' for cell) became equals to infinity from approximately 1000-1500 time steps. Why is it? I will be very glad for answer on this problem. ----------------------------------------------------------------- With best wishes, Artem R. Dr. Artem R. Khabibullin Department of Theoretical Physics, Kazan Federal University. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100702/1232130d/attachment-0001.htm
