[Pw_forum] Electronic calculations
I am requesting for an input file to perform first principle electronic calculations of silicon ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] quantum entanglement using quantum espresso
am an undergraduate student maasaimara university in kenya intrested in quantum entanglement.am requesting for your assistance on simulation of entanglement using quantum espresso..Aninput file will serve better ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] difference in output from dynmat.x and matdyn.x
Dear espresso users and developers, I am trying to obtain the phonon dispersion of alpha-quartz (SiO2) which has a 9 atom unit cell. I ran ph.x on a 3 x 3 x 3 q-point grid. I am seeing some strange behavior where there seems to be a difference in the frequencies output from dynmat.x and matdyn.x. I will explain my problem below. I diagonalized the dynamical matrix at the gamma point using dynmat.x with acoustic sum rule set to crsytal. Since SiO2 is a polar material, LO-TO splitting will need to be considered at the gamma point but I am ignoring it currently (I did not specify any direction for LO-TO splitting in the dynmat.x input). This gave me the following 27 frequencies (in cm^-1) at the gamma point: (0,0,0, 152.24, 175.57, 175.57, 256.32, 256.32, 341.09, 354.41, 376.86, 376.86, 419.01, 419.01, 435.37, 455.70, 659.12, 659.12, 744.54, 754.62, 1034.38, 1034.38, 1040.20, 1051.12, 1139.60, 1139.60) I also used q2r.x (with zasr = 'crystal') to obtain the force constants and then used matdyn.x (with asr = 'crystal') to obtain the frequencies at the gamma point. However with matdyn.x, I obtain the following frequencies at the gamma point: (-29.4088,-22.2535,-22.2535,152.2412,175.8141,175.8141, 256.3373, 256.3373, 341.0892, 355.4227, 376.0495 , 376.0495, 418.6344, 418.6344, 435.3710, 453.6862, 659.7607, 659.7607, 746.4843, 754.8867, 754.8867, 1034.1751, 1034.1751, 1039.7590, 1051.1207, 1139.8191, 1139.8191) Could someone please explain why I am getting imaginary frequencies from matdyn.x while dynmat.x gives real frequencies at the same q-point (gamma in this case)? Thanks, Sridhar Purdue University ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] QHA
Hi I've calculated the thermodynamic properties, But in the case of spin-orbit, column of F_vibration and E_internal are empty and NAN written, whilst column of spesific heat is calculated. What caused this? masoud alavi plz help me ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] Accelerating multiple calculations with same phase
Dear Quantum espresso users and developers, I am working on several phases, investigating for each phase I need to 1-Determine lattice constant and atomic positions with non magnetic state 2-Determine magnetic ground states (by testing all of magnetic states possibilities for each ions) 3-Determine lattice constant and atomic positions with magnetic states 4-Construct several super-cells and invert ion position. As you can see, I must do lot of calculation for each phase by modifying it slightly. My question is what's the best procedure to do that safely and/or quickly, I mean whether: -Do it safely and delete wfc and xml data for every new calculation (I am calculation on the same folder for each precedent step) -Do it more quickly and keep old wfc and xml data. Another question related with same topic: how relax subroutine success improving convergence steps just after running the first cycle? can I capitalize something for my case? P.S. : Thanks in advance. Youssef Aharbil PhD Laboratory of Physics and Chemistry of Material Morocco ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
[Pw_forum] BoltzWann for one-dimensional systems?
Dear All, I am trying to calculate Wannier90 with BoltzWann for one-dimensional systems such as Carbon Nanotubes or Nanowires. However, BoltzWann does not seem to support the 1-D systems. Any advice that can help me in this problem?. Thank you very much for your support. Sincerely yours, Nguyen Tuan Hung Department of Physics, Tohoku University add: Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578, Janpan tell: +81-22-795-7754 fax 6447 ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
