[Pw_forum] Bad energetic of Li adsorbed graphene by DFT-D2 using QE

Saif Ullah kiterunner7 at gmail.com
Wed Oct 4 22:20:31 CEST 2017


Thanks for the response. I have used different values of
ecutwfc/ecutrho taken from the literature (30, 35, 40, 60) with different
types of pseudopotentials available. With paw pps, the adsorption energy is
overestimated while with ultrasoft, it is underestimated. I have used
vc-relax as well as relax. The adsorption of Li on graphene results in a
non-magnetic solution as per vasp, siesta, gaussian, and qe. Initially, I
have used spinfull calculations with qe, but the final result is a non
magnetic one therefore, after that, i used spinless calculations. I don't
know what to do. I have also tried the methodology of this paper having
DOI: 10.1021/acs.jpcc.6b05458

Regards from Brazil
Saif
Department of physics, UFJF, Brazil

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On Wed, Oct 4, 2017 at 1:53 PM, Ari P Seitsonen <Ari.P.Seitsonen at iki.fi>
wrote:

>
> Dear Saif Ullah,
>
>   (Next time with your affiliation, please)
>
>   I wonder why you have commented out the spin polarisation; did you do
> the same witht eh other codes? Since your system is neutral, it looks to me
> as if your system would have an odd number of electrons, but the spin
> polarisation is not accounted for. Did you check that your energies are
> well converged, considering that you are performing calculations with
> 'vc-relax'?
>
>     Greetings from Sunny Paris,
>
>        apsi
>
> -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=
> -=*=-=*=-=*=-=*=-
>   Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
>     Ecole Normale Supérieure (ENS), Département de Chimie, Paris
>     Mobile (F) : +33 789 37 24 25    (CH) : +41 79 71 90 935
>
>
>
> On Wed, 4 Oct 2017, Saif Ullah wrote:
>
> Dear QE users,
>> I'm trying to reproduce the Li adsorbed graphene with DFT-D2 using QE.
>> The adsorption energy is very much underestimated (-0.66 eV/Li) as
>> compared to the values found in the literature. My SIESTA vdW-DF/DZP
>> value is -1.11 eV/Li, pretty much in agreement with the literature. I have
>> used different cutoff values with different pseudopotentials. I don't
>> know where is the problem. Following is one of my inputs. Need your
>> suggestions, please. Thanks
>>
>> &CONTROL
>>    calculation='vc-relax',
>>   outdir='.',
>>   prefix='calc',
>>   pseudo_dir='.',
>>   verbosity='high',
>>  tstress=.true.
>> tprnfor=.true.
>> etot_conv_thr=1.0D-4
>> forc_conv_thr=1.D-3
>> wf_collect=.true.
>> nstep=1000
>> /
>>
>> &SYSTEM
>>   ibrav=0,
>>   nat=51,
>>   ntyp=2,
>>   ecutwfc=40,
>>   ecutrho=320,
>>    input_dft='PBE',
>>   occupations='smearing',
>>   smearing='mp',
>>   degauss=0.01d0,
>>  vdw_corr='Grimme-D2',
>> !  nspin=2,
>> !  starting_magnetization(1)=0.7
>> !  starting_magnetization(2)=0.6
>> /
>>
>> &ELECTRONS
>>    diagonalization='cg',
>>   conv_thr=1d-08,
>>   mixing_mode='local-TF',
>>   mixing_beta=0.500d0,
>>  electron_maxstep=2000
>> /
>> &IONS
>> ion_dynamics='bfgs'
>> /
>> &CELL
>>    cell_dynamics = 'bfgs' ,
>>   cell_dofree='2Dxy'
>> /
>> ATOMIC_SPECIES
>> C 12.010700d0 C.pbe-van_ak.UPF
>> Li  6.941000d0 Li.pbe-n-van.UPF
>> CELL_PARAMETERS (angstrom)
>>   12.353060724   0.000889035  -0.201450000
>>   -6.175669462  10.698563666   0.201310000
>>   -0.000049454   0.000028549  20.000000000
>>
>> ATOMIC_POSITIONS (angstrom)
>> C       -0.123777599   0.044352021   0.750813339
>> C        2.347139643   0.044536664   0.710530839
>> C        4.816959818   0.046608474   0.671588196
>> C        7.288030852   0.047974520   0.631371477
>> C        9.759254756   0.046949526   0.590970165
>> C       -1.361324273   2.182837743   0.784592128
>> C        1.111661447   2.176898866   0.738849472
>> C        3.584693057   2.183131578   0.703985603
>> C        6.053702309   2.186196980   0.671658550
>> C        8.522771292   2.186413475   0.631364175
>> C       -2.598243992   4.325485482   0.824910219
>> C       -0.131078480   4.322022349   0.764237921
>> C        2.354133011   4.322141066   0.723759919
>> C        4.821870209   4.325914119   0.703967494
>> C        7.288439627   4.327051393   0.671562970
>> C       -3.831089225   6.466525503   0.871657296
>> C       -1.366959478   6.470638409   0.819586551
>> C        1.111648295   6.474564682   0.764205441
>> C        3.590771165   6.470877940   0.738791095
>> C        6.055337825   6.467163164   0.710460311
>> C       -5.064123742   8.605360424   0.914570582
>> C       -2.595447017   8.606844025   0.871611006
>> C       -0.124940436   8.609595937   0.824824937
>> C        2.349153535   8.609719150   0.784488796
>> C        4.820054590   8.607291549   0.750697179
>> C       -0.125510159   1.469181337   0.757732918
>> C        2.348583973   1.469399905   0.717413261
>> C        4.819499832   1.472058312   0.683659878
>> C        7.288388407   1.473415839   0.646082581
>> C        9.757057163   1.472349661   0.603098319
>> C       -1.367183927   3.608059861   0.792700719
>> C        1.111411672   3.604765482   0.737260404
>> C        3.590550668   3.608523771   0.711920217
>> C        6.055141240   3.612373570   0.683651546
>> C        8.521773207   3.612481509   0.643390074
>> C       -2.598108408   5.752895502   0.838312859
>> C       -0.130966528   5.757101185   0.777712574
>> C        2.354245670   5.757343547   0.737229826
>> C        4.822007602   5.753541812   0.717366687
>> C        7.288591341   5.752608946   0.684948021
>> C       -3.829804361   7.892507839   0.886438561
>> C       -1.360854441   7.895696352   0.838263118
>> C        1.112121068   7.902104754   0.792620096
>> C        3.585162055   7.896134775   0.757637017
>> C        6.054187493   7.893269674   0.725270353
>> C        1.111459010  -0.667769729   0.725378109
>> C        3.582681447  -0.666400412   0.685002360
>> C        6.052708940  -0.664305301   0.643406933
>> C        8.523624623  -0.664119335   0.603107212
>> C       10.993446884  -0.665855193   0.564139854
>> Li       1.142006551   5.022080560   2.622103194
>> K_POINTS automatic
>>  6 6 1 0 0 0
>>
>>
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