[QE-users] Computer dependent phonon frequencies

Leonid Kahle leonid.kahle at epfl.ch
Wed Oct 9 15:56:47 CEST 2019


Dear Jibiao,

One explanation could be that the thresholds you chose are not tight enough.
You could check whether the problem is alleviated if you tighten these.
For the scf calculation, set conv_thr in electrons to something much 
tighter than the default, I would suggest 1.0D-10.
Also your threshold for tr2_ph in inputph can be tighter. If the 
discrepancy decreases, than the frequencies are just imprecise due to 
bad convergence.

Best,

     Leonid Kahle


On 10/9/19 3:48 PM, Jibiao Li wrote:
> Dear Prof. Paolo Giannozzi,
>
> The two computers have the exact same OS (ubuntu), compilers (ifort), 
> libraries, and parallel environments installed. It really strange why 
> different results produced by the same inputs. Can anyone help me?
>
> Best
>
> ------------------
> /*Dr. Jibiao Li, */
> /*Department of Material Science and Engineering*/
> /*Yangtze Normal University*/
> /*Juxian Dadao 16#, Fuling, Chongqing, China*/
> /*Email: jibiaoli at yznu.edu.cn, jibiaoli at foxmail.com, 
> jibiao.li at hotmail.com*/
> /*Homepage: https://www.researchgate.net/profile/Jibiao_Li*/
>
>
> ------------------ Original ------------------
> *From:* "p.giannozzi"<p.giannozzi at gmail.com>;
> *Date:* Wed, Oct 9, 2019 09:42 PM
> *To:* "Quantum ESPRESSO users Forum"<users at lists.quantum-espresso.org>;
> *Subject:* Re: [QE-users] Computer dependent phonon frequencies
>
> Hard to say with no knowledge (or even with the knowledge) of which 
> computers, compilers, libraries, parallel execution, ... produce 
> strange results.
>
> Paolo
>
> On Wed, Oct 9, 2019 at 2:19 PM Jibiao Li <jibiaoli at foxmail.com 
> <mailto:jibiaoli at foxmail.com>> wrote:
>
>     Dear QE experts,
>
>     I am studying mixed H2O/OH phase on Ag(111) using QE 6.4.1. To my
>     suprise, however, to different computers gave totally different
>     vibrational frequencies, with the exact same input files. Is there
>     anybody to help me?
>
>     Computer A gave
>          freq ( 46 - 46) =         24.2  [cm-1]   --> A               I+R
>          freq ( 47 - 47) =         72.8  [cm-1]   --> A               I+R
>          freq ( 48 - 48) =        137.6  [cm-1]   --> A               I+R
>          freq ( 49 - 49) =        199.5  [cm-1]   --> A               I+R
>          freq ( 50 - 50) =        308.7  [cm-1]   --> A               I+R
>          freq ( 51 - 51) =        379.5  [cm-1]   --> A               I+R
>          freq ( 52 - 52) =        585.2  [cm-1]   --> A               I+R
>          freq ( 53 - 53) =        800.0  [cm-1]   --> A               I+R
>          freq ( 54 - 54) =        872.2  [cm-1]   --> A               I+R
>          freq ( 55 - 55) =        901.9  [cm-1]   --> A               I+R
>          freq ( 56 - 56) =        998.4  [cm-1]   --> A               I+R
>          freq ( 57 - 57) =       1529.7  [cm-1]   --> A               I+R
>          freq ( 58 - 58) =       2914.9  [cm-1]   --> A               I+R
>          freq ( 59 - 59) =       3064.3  [cm-1]   --> A               I+R
>          freq ( 60 - 60) =       3610.2  [cm-1]   --> A               I+R
>     Computer B gave
>          freq ( 46 - 46) =         33.0  [cm-1]   --> A               I+R
>          freq ( 47 - 47) =         45.1  [cm-1]   --> A               I+R
>          freq ( 48 - 48) =         54.1  [cm-1]   --> A               I+R
>          freq ( 49 - 49) =         78.2  [cm-1]   --> A               I+R
>          freq ( 50 - 50) =         82.4  [cm-1]   --> A               I+R
>          freq ( 51 - 51) =         99.1  [cm-1]   --> A               I+R
>          freq ( 52 - 52) =        108.9  [cm-1]   --> A               I+R
>          freq ( 53 - 53) =        114.4  [cm-1]   --> A               I+R
>          freq ( 54 - 54) =        188.3  [cm-1]   --> A               I+R
>          freq ( 55 - 55) =        590.6  [cm-1]   --> A               I+R
>          freq ( 56 - 56) =       1101.8  [cm-1]   --> A               I+R
>          freq ( 57 - 57) =       1533.4  [cm-1]   --> A               I+R
>          freq ( 58 - 58) =       2812.1  [cm-1]   --> A               I+R
>          freq ( 59 - 59) =       3644.5  [cm-1]   --> A               I+R
>          freq ( 60 - 60) =       3786.8  [cm-1]   --> A               I+R
>
>     *Why the two computers give totally different results? *
>
>     *
>     *
>
>
>      &CONTROL
>                      calculation = 'scf' ,
>                     restart_mode = 'from_scratch' ,
>                           outdir = './' ,
>                       pseudo_dir = '/home/jibiaoli/pseudo/' ,
>                           prefix = 'sym' ,
>                          tstress = .true. ,
>                          tprnfor = .true. ,
>      /
>      &SYSTEM
>                            ibrav = 0,
>                        celldm(1) = 9.456004324,
>                              nat = 20,
>                             ntyp = 3,
>                          ecutwfc = 49 ,
>                          ecutrho = 411 ,
>                      occupations = 'smearing' ,
>                          degauss = 0.02 ,
>                         smearing = 'methfessel-paxton' ,
>                         vdw_corr = 'DFT-D',
>      /
>      &ELECTRONS
>                      mixing_beta = 0.3 ,
>                  diagonalization = 'david' ,
>      /
>     CELL_PARAMETERS alat
>          0.866025404    0.500000000    0.000000000
>          0.866025404   -0.500000000    0.000000000
>          0.000000000    0.000000000    5.400000000
>     ATOMIC_SPECIES
>        Ag  107.8682  Ag.pbe-n-kjpaw_psl.1.0.0.UPF
>         O   15.99940  O.pbe-n-kjpaw_psl.1.0.0.UPF
>         H    1.00800  H.pbe-kjpaw_psl.1.0.0.UPF
>     ATOMIC_POSITIONS angstrom
>     O        5.986597700   0.051902808  11.800640138
>     H        6.530086903   0.896034963  11.935550794
>     H        6.519207423  -0.788895855  11.940829013
>     O        2.800029893   0.013830142  11.748050047
>     H        3.756125095   0.022425916  11.956803063
>     Ag      -0.454154628   0.136836718   9.568098196
>     Ag       5.307442766   0.123896111   9.577760992
>     Ag       2.445911493   0.129358587   9.587754292
>     Ag       2.920157088   1.499919274   7.139192063
>     Ag       1.485120252  -0.981971793   7.160426239
>     Ag       4.380244685  -0.987689704   7.134282475
>     Ag       2.889028971  -1.667975200   4.717759990    0 0   0
>     Ag       4.333537867   0.833997281   4.717759990    0 0   0
>     Ag       5.778055146  -1.667970358   4.717759990    0 0   0
>     Ag       0.000000000   0.000000000   2.358879995    0 0   0
>     Ag       5.778052352   0.000009682   2.358879995    0 0   0
>     Ag       2.889026176   0.000004841   2.358879995    0 0   0
>     Ag       2.889023381   1.667984881   0.000000000    0 0   0
>     Ag       1.444514485  -0.833987600   0.000000000    0 0   0
>     Ag       4.333540661  -0.833982759   0.000000000    0 0   0
>     K_POINTS automatic
>       6 6 1   0 0 0
>
>     phonons at Gamma
>      &inputph
>       tr2_ph=1.0d-14,
>       prefix='sym',
>       alpha_mix=0.1,
>       fildyn='phG.dyn',
>       amass(1)=107.8682,
>       amass(2)=15.999,
>       amass(3)=1.0079,
>       outdir='./'
>       nat_todo=5,
>      /
>     0.0 0.0 0.0
>     1 2 3 4 5
>
>
>     ------------------
>     /*Dr. Jibiao Li, */
>     /*Department of Material Science and Engineering*/
>     /*Yangtze Normal University*/
>     /*Juxian Dadao 16#, Fuling, Chongqing, China*/
>     /*Email: jibiaoli at yznu.edu.cn <mailto:jibiaoli at yznu.edu.cn>,
>     jibiaoli at foxmail.com <mailto:jibiaoli at foxmail.com>,
>     jibiao.li at hotmail.com <mailto:jibiao.li at hotmail.com>*/
>     /*Homepage: https://www.researchgate.net/profile/Jibiao_Li*/
>     _______________________________________________
>     Quantum ESPRESSO is supported by MaX
>     (www.max-centre.eu/quantum-espresso
>     <http://www.max-centre.eu/quantum-espresso>)
>     users mailing list users at lists.quantum-espresso.org
>     <mailto:users at lists.quantum-espresso.org>
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>
>
>
> -- 
> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>
> _______________________________________________
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