Dear Clarence,
An energy barrier should represent a local event, ie, not periodically repeted.
For these reason, the Kpoint mesh should not affect the energy barrier.
I conclude from your results that you have long range interactions and that
your supercell is too small along xy to represent an isolated Li.
Regards,
Antoine Jay
LAAS-CNRS
Toulouse, France
Le Mercredi, Mars 24, 2021 03:52 CET, LEUNG Clarence <liangxy...@hotmail.com> a
écrit:
Dear QE users,
Recently, I study on the Li ion diffusion on 2D layer surface. And I found that
the K-point in neb.x significantly affects the barrier. The following figure is
5*5*1, 9*9*1 and 13*13*1,
Except point, all set are fixed as follows:
BEGIN
BEGIN_PATH_INPUT
&PATH
restart_mode = 'from_scratch'
string_method = 'neb',
nstep_path = 500,
ds = 1.D0,
opt_scheme = "broyden",
num_of_images = 10,
CI_scheme = "no-CI",
path_thr = 0.05D0,
/
END_PATH_INPUT
BEGIN_ENGINE_INPUT
&CONTROL
nstep = 200 ,
wf_collect = .true. ,
verbosity='low',
max_seconds = 320000 ,
etot_conv_thr = 3.7D-7 ,
forc_conv_thr = 4.0D-4 ,
/
&SYSTEM
ibrav=4,
celldm(1)=16.8205089265d0, celldm(3)=2.8086637164d0,
nat=28,
ntyp=3,
ecutwfc=60,
ecutrho=600,
input_dft='PBE',
occupations='smearing',
smearing = 'gaussian' ,
degauss = 0.01 ,
nspin = 2 ,
starting_magnetization(1) = 0.5 ,
vdw_corr = 'DFT-D3' ,
/
&ELECTRONS
conv_thr=1d-07,
mixing_beta=0.7d0,
mixing_mode ='local-TF',
electron_maxstep = 500 ,
/
&IONS
/
ATOMIC_SPECIES
Li 6.941000d0 Li.pbe-sl-kjpaw_psl.1.0.0.UPF
N 14.006700d0 N.pbe-n-kjpaw_psl.1.0.0.UPF
Ti 47.867000d0 Ti.pbe-spn-kjpaw_psl.1.0.0.UPF
K_POINTS {automatic}
1 1 1 0 0 0
BEGIN_POSITIONS
FIRST_IMAGE
ATOMIC_POSITIONS {crystal}
Ti 0.7770490991 0.2207650450 0.4526649491
Ti 0.8912354588 0.1122845729 0.5447173889
N 0.6666667383 0.0000000000 0.4995961962
Ti 0.7780555528 0.5556941072 0.4517577041
Ti 0.8890435897 0.4447534785 0.5440905933
N 0.6673919617 0.3329974904 0.4979423184
Ti 0.7770488498 0.8896175800 0.4526648274
Ti 0.8890434165 0.7776226563 0.5440907450
N 0.6673920333 0.6677278762 0.4979422530
Ti 0.1088705771 0.2211023009 0.4510416620
Ti 0.2233051542 0.1132758120 0.5420585003
N -0.0010611379 -0.0007252950 0.4979422530
Ti 0.1109726480 0.5556945774 0.4517577341
Ti 0.2233049049 0.4433625308 0.5420583786
N -0.0010611379 0.3329974188 0.4979422530
Ti 0.1109728212 0.8886111263 0.4517575824
Ti 0.2219134870 0.7776229056 0.5440906233
N 0.0000000000 0.6666667383 0.4979808302
Ti 0.4455657413 0.2211020516 0.4510417837
Ti 0.5543824685 0.1122843997 0.5447172372
N 0.3336691046 -0.0007252950 0.4979422530
Ti 0.4455652711 0.5577968215 0.4510418137
Ti 0.5533912294 0.4433620606 0.5420583486
N 0.3333332617 0.3333332617 0.4956870765
Ti 0.4459022777 0.8896177532 0.4526649791
Ti 0.5543819983 0.7754308633 0.5447172672
N 0.3336691762 0.6677278046 0.4979421876
Li 0.3333330289 0.3333338479 0.6400903690
INTERMEDIATE_IMAGE
ATOMIC_POSITIONS {crystal}
Ti 0.7789152822 0.2220836302 0.4501659003
Ti 0.8888446372 0.1110228518 0.5426653048
N 0.6673156201 -0.0006488818 0.4964052852
Ti 0.7789152822 0.5568316396 0.4501659003
Ti 0.8867836243 0.4433916373 0.5427300585
N 0.6675598953 0.3337799476 0.4952771792
Ti 0.7777776240 0.8888888058 0.4505257421
Ti 0.8888446372 0.7778214356 0.5426653048
N 0.6673156201 0.6679645019 0.4964052852
Ti 0.1098352888 0.2220838795 0.4501657786
Ti 0.2237552464 0.1118774483 0.5405467345
N -0.0012977636 -0.0006488818 0.4964052852
Ti 0.1111114878 0.5555557376 0.4510371855
Ti 0.2232753282 0.4433921075 0.5427300885
N 0.0001334406 0.3336001430 0.4969839949
Ti 0.1098352888 0.8877513969 0.4501657786
Ti 0.2232753282 0.7798828710 0.5427300885
N 0.0001334406 0.6665332977 0.4969839949
Ti 0.4444451994 0.2222225935 0.4488650365
Ti 0.5547895931 0.1118772751 0.5405465828
N 0.3328866474 -0.0008932286 0.4952771138
Ti 0.4445836925 0.5568321098 0.4501659303
Ti 0.5547895931 0.4429119684 0.5405465828
N 0.3328866474 0.3337798760 0.4952771138
Ti 0.4445836925 0.8877515701 0.4501659303
Ti 0.5556437194 0.7778216849 0.5426651831
N 0.3330664520 0.6665332261 0.4969839295
Li 0.4444459557 0.2222229977 0.6387918156
LAST_IMAGE
ATOMIC_POSITIONS {crystal}
Ti 0.7788993600 0.2211011068 0.4510426589
Ti 0.8877157525 0.1122843572 0.5447186005
N 0.6670022049 -0.0007257761 0.4979412162
Ti 0.7788993600 0.5577982408 0.4510426589
Ti 0.8867240759 0.4433618631 0.5420585485
N 0.6666666667 0.3333333333 0.4956851811
Ti 0.7792359152 0.8896179514 0.4526660159
Ti 0.8877157525 0.7754310455 0.5447186005
N 0.6670022049 0.6677279810 0.4979412162
Ti 0.1103825154 0.2207645516 0.4526660159
Ti 0.2245690642 0.1122843572 0.5447186005
N 0.0000000000 0.0000000000 0.4995954192
Ti 0.1113906330 0.5556953102 0.4517586619
Ti 0.2223762417 0.4447520239 0.5440918698
N 0.0007257761 0.3329977951 0.4979412162
Ti 0.1103825154 0.8896179514 0.4526660159
Ti 0.2223762417 0.7776238680 0.5440918698
N 0.0007257761 0.6677279810 0.4979412162
Ti 0.4422022260 0.2211011068 0.4510426589
Ti 0.5566382465 0.1132760338 0.5420585485
N 0.3322720190 -0.0007257761 0.4979412162
Ti 0.4443051566 0.5556953102 0.4517586619
Ti 0.5566382465 0.4433618631 0.5420585485
N 0.3322720190 0.3329977951 0.4979412162
Ti 0.4443051566 0.8886098338 0.4517586619
Ti 0.5552480857 0.7776238680 0.5440918698
N 0.3333333333 0.6666666667 0.4979808492
Li 0.6666674857 0.3333338479 0.6400822952
END_POSITIONS
END_ENGINE_INPUT
END
Thank you for your suggestion in advances!
Best regards,
Clarence
Postdoctoral Fellow
City University of Hong Kong
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