[Pw_forum] NEB "spring constants"

Hello, Can someone please explain the criteria for the proper choice of "k_min" and "k_max" in NEB calculations ? The default choice in QE 4.3.2 is k_min = k_max = 0.2 a.u.. However, when I run NEB job, the start-up information near the beginning of the output file says: suggested

[Pw_forum] Restarting a Geometry Optimization

e "restart" keyword, of course, but what files are needed from the previous run ? Is there a particular naming convention for these files that must be followed ? Is there a special subdirectory where these files have to be placed ? Thanks in Advance, Vic Bermudez Victor M

[Pw_forum] Spin-Unrestricted Calculation for O2 Adsorption

ire supercell + O2. There has to be a better way, but I haven't been able to find anything in the documentation or at the users' forum. Any help would be much appreciated. Thanks, Vic Bermudez Victor M. Bermudez Code 6876 U.S. Naval Research Laboratory 4555 Overlook Ave., S.W.

[Pw_forum] Magnetization in the Adsorption of Molecular O2

6011 Ga 6.277129268 1.147167971 5.989478016 . . . . H5 -7.635543780 -4.277997026 -6.2856422810 0 0 H5 -3.357548712 -0.00728 -6.2856413790 0 0 H5 -3.357548071 4.277997544 -6.2856418930 0 0 H5 -3.357547485 -4.277997519 -6.285

[Pw_forum] Problem With Spin-Unrestricted Calculation for Adsorbed Singlet O2

20342683 8.304609872 7.300817121 Sb 2.096288690 4.750078727 6.845581956 Ga 1.894355025 -5.388868218 6.360351760 . . . H5 -3.357548071 4.277997544 -6.2856418930 0 0 H5 -3.357547485 -4.277997519 -6.2856426880 0 0 K_POINTS automatic 3 4 1 0 0 0 I woul

[Pw_forum] Excited Atom Approaching a Surface

x27;, which has to be specified for Occupations='From_Input' ? Is there a reasonable way to approach this kind of calculation in Quantum Espresso ? I've searched the User Forum but couldn't find anything helpful on this subject. Thanks, Vic Bermudez Victor M. Bermudez Code 6876

[Pw_forum] Question About Lowdin Charges

t my interpretation of the Lowdin numbers is consistent with these discussions. Any advice would be much appreciated. Thanks, Vic Bermudez Victor M. Bermudez Code 6877 Naval Research Laboratory 4555 Overlook Ave., S.W. Washington, DC 20375-5347 victor.bermu...@nrl.navy.mil Phone: 202-767-6728

[Pw_forum] Problem with PAW vs. USP

200, conv_thr=1.0D-9, mixing_mode='plain', mixing_beta=0.7D0 / &IONS ion_dynamics='bfgs', upscale=1.D0 / ATOMIC_SPECIES Zr 91.22 Zr.pbe-spn-kjpaw_psl.0.2.3.UPF ATOMIC_POSITIONS {crystal} Zr 0.000 0.000 0.000 Zr 0.333 0.667 0.500 K

Re: [Pw_forum] Problem with PAW vs. USP

atom. Your comments point to a problem with my free-atom calculation, which I will investigate further. Thanks again. This is very helpful. Your results also validate the PAW pseudopotential for Zr, which was my main purpose in this exercise. Best Wishes, Vic Bermudez Victor M. Bermudez E-mail:

Re: [Pw_forum] Problem with PAW vs. USP

ther users will find this helpful. Best Wishes, Vic Bermudez Victor M. Bermudez E-mail: bermu...@alum.mit.edu Sample Free-Atom Input File &CONTROL calculation='scf', title='free Zr atom - should give (3)F ground state - using PBE/PAW',

[Pw_forum] Problem with "nmix_ph" in ph.x

Hello All, I'm running ph.x in QE vers. 5.0 and having a bit of a convergence problem. Reducing the value of alpha_mix(1) from the default value of 0.7 helps, but if I try to change "nmix_ph" the program crashes immediately with an error message saying "wrong nmix used". Is this a bug in

[Pw_forum] GIPAW Problem (Cholesky)

int #1 of 1 pool # 1 *** I notice that there are statements like "projectors nearly linearly dependent". I'm not sure what this means, but it can't be good. I should also note that this calculation is being done for a rather large system (1280 elec

[Pw_forum] Trying to Generate a Pseudo-Hydrogen Pseudopotential

ge (1.25). In spite of a previous forum exchange indicating that the presently-available PZ PPs are adequate for pseudo-Hs in GGA calculations, I would nevertheless like to generate one of my own as a learning experience. Can someone please point me in the right direction ? Thanks, Vic Ber

[Pw_forum] Trying to Generate a Pseudo-Hydrogen Pseudopotential

they available somewhere ? Or are you saying that it doesn't matter at all which functional is used for the pseudo-H PPs ? Thank you, Vic Bermudez Victor M. Bermudez Code 6876 U.S. Naval Research Laboratory 4555 Overlook Ave., S.W. Washington, DC 20375-5347 Phone: 202-767-6728 FAX: 202-767

[Pw_forum] SCF Correction Too Large ...

ce for your help and advice. Best Wishes, Vic Bermudez Victor M. Bermudez Code 6876 U.S. Naval Research Laboratory 4555 Overlook Ave., S.W. Washington, DC 20375-5347 Phone: 202-767-6728 FAX: 202-767-1165 E-mail: victor.bermudez at nrl.navy.mil

[Pw_forum] NEB Convergence Problem

Greetings All, I'm struggling with a NEB calculation, and I wonder if someone can advise me. I first converged the path using NEB without CI. This took many iterations (810 to be exact), but it got there in the end. I then restarted with the optimized path and CI set to 'auto'. As you can

[Pw_forum] NEB Convergence Problem

effect isolate an IS --> TS --> FS segment centered on the true (highest-energy) TS in the path. Is this the correct thing to do ? My activation energy would then be the difference between this TS and a system consisting of isolated free HF and bare OH-terminated SiC (which I can easily com

[Pw_forum] Problem With Total-Energy Convergence vs. ecutwfc

Hello, I seem to be having some serious trouble getting total energies to converge as I vary "ecutwfc" and "ecutrho". This is for a slab-model calculation, using PBE and USPP's, for an HF molecule reacting with the surface of Si3N4. The total energy results I get in representative calcu

[Pw_forum] Pseudopotentials for Pseudo-Hydrogens

Hello, I'm setting up a slab calculation for the GaSb (100) surface using PW91 USPP's for Ga and Sb. I want to passivate the "bottom" (Ga-terminated) surface with pseudo-hydrogens, which will require two Z=5/4 pseudo-H's per Ga. However, the QE website gives only PZ pseudopotentials for ps

[Pw_forum] Problem with NEB Images (vers. 4.3.1)

'relax' or 'scf' calculation. Has anyone seen this sort of behavior before ? I've looked for, and not found, anything relevant in previous postings. Thanks, Vic Bermudez Victor M. Bermudez Code 6876 U.S. Naval Research Laboratory 4555

[Pw_forum] problem with symmetry recognition

ratively if more than one lattice constant is being optimized. Hope this helps. Best Wishes, Vic Bermudez Victor M. Bermudez Code 6876 U.S. Naval Research Laboratory 4555 Overlook Ave., S.W. Washington, DC 20375-5347 -- next part -- An embedded and cha

[Pw_forum] Restarting a NEB Calculation

#x27;) are needed in the input file ? One final question ... does it make any difference whether I restart using the latest .path file from the previous run or manually, using the latest atom positions in the .crd file ? Thanks, Vic Bermudez Victor M. Bermudez Code 6876

[Pw_forum] Polarized Infrared Intensities

Hello, I have a question about the IR intensities that are returned by Dynmat.x following a Ph.x calculation. I am assuming that these relate to normal-incidence transmission for radiation propagating along the z-axis. My system is not isotropic. How would I get the corresponding intensiti

[Pw_forum] DOS Without 'Relax' ?

Hello All, I'm doing an MD calculation at finite temperature, and I'd like to investigate the DOS at various times in the simulation. Is it physically meaningful to compute a DOS without first relaxing the system to the total-energy minimum in a static (T=0) calculation ? It seems like it

[Pw_forum] NEB Image Continuity

in vers. 5.1. Thank you in advance for your help and advice. Best Wishes, Vic Bermudez Victor M. Bermudez E-mail: bermu...@alum.mit.edu ___ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum

[Pw_forum] Spin-Polarized NEB

Hello, I'm doing a NEB calculation for a reaction where I suspect that the transition state might be paramagnetic. In the "engine_input" section I set 'nspin=2', and I set a non-zero starting magnetization for one of the atom types. In the first SCF cycle of the first NEB iteration the abs

Re: [Pw_forum] Amorphous Solid

Hello Sarah, Here's another good place to look for ideas on making amorphous silica models http://journals.aps.org/prb/abstract/10.1103/PhysRevB.71.024208 Best Wishes, Vic Bermudez Victor M. Bermudez E-mail: bermu...@alum.mit.edu ___ Pw_