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标题: Ag原子穿过MoS2单S缺陷单层的CI-NEB计算不收敛，原子受力过大 [打印本页]

作者
Author: tyut-siggma 时间: 2024-5-7 15:22
标题: Ag原子穿过MoS2单S缺陷单层的CI-NEB计算不收敛，原子受力过大
上个月刚接触CI-NEB计算过渡态。纯小白遇到如下问题
我在计算Ag原子穿过MoS2单S缺陷单层的能量势垒需要使用CI-NEB，参考文献doi：10.1088/1361-6528/acb69d。初态末态的POSCAR文件如下。
初态POSCAR：
1.00000000000000
   9.5471000671000006 0.0000000000000000 0.0000000000000000
-4.7735214086999997 8.2680477171000000 0.0000000000000000
   0.0000000000000000 0.0000000000000000 28.1212005615000002
Mo S Ag
   9 17    1
Cartesian
0.0164424572657 1.84757761591 14.0433503379
3.18259553955 1.8225089213 14.0190996384
6.34787498687 1.84738007924 14.0432762134
-1.59162580149 4.58841792637 14.0594252341
1.57629055395 4.60183985572 14.0178142635
4.78737575154 4.60094711837 14.0185880403
-3.1871865552 7.35251888387 14.059852108
0.00419758892221 7.35266097417 14.0595949991
3.18200597915 7.33027584556 14.0433682636
1.59888819561 0.909499082058 12.4749851955
1.60267933015 0.951859304792 15.6100620219
4.76545057665 0.909489963644 12.474634817
4.76208106734 0.951613770249 15.610231467
7.95581894208 0.918865947888 12.4962048089
7.95580846208 0.918870826296 15.5884866149
-0.00561481159927 3.68640953888 12.4740107428
0.0333522136958 3.66910087119 15.6098284453
3.18197501061 3.67524057312 12.5077685825
6.36924776371 3.6864772737 12.4742450867
6.33092149623 3.66857678546 15.6101338078
-1.59168944083 6.43138136596 12.5101069469
-1.59146483426 6.43108070956 15.616043221
1.5783643225 6.42996900997 12.4742274086
1.61287593832 6.40461785017 15.6097074092
4.78569879587 6.42930159825 12.4748114048
4.75100123825 6.40431626629 15.6098422474
3.18099724974 3.67655152811 16.1345237871

末态POSCAR：
1.00000000000000
   9.5471000671000006 0.0000000000000000 0.0000000000000000
-4.7735214086999997 8.2680477171000000 0.0000000000000000
   0.0000000000000000 0.0000000000000000 28.1212005615000002
Mo S Ag
   9 17    1
Cartesian
0.0138689350153 1.84494208728 14.0306708988
3.15488932364 1.87126360419 14.0141179467
6.34716439862 1.85842389247 14.0232185917
-1.59277419671 4.59362347499 14.0490448228
1.60729545113 4.55196665093 14.0130586146
4.77009220809 4.59092460539 13.9624651878
-3.18253436125 7.34604392713 14.0498843164
0.00163552317452 7.3499502046 14.05659256
3.19222987744 7.32309806602 14.0232429345
1.61376372379 0.921018708098 12.4715376861
1.60159249619 0.967437471195 15.6049864665
4.75189626632 0.914137711975 12.4758941563
4.7424304028 0.984771086325 15.5906437664
7.95315277735 0.916785512353 12.4788866243
7.94849003168 0.914106913536 15.5713696605
0.0149391651212 3.6915408809 12.4695188373
0.0484443123875 3.65878612669 15.6043890593
3.16874204665 3.66608722598 12.4649774512
6.37864903228 3.69271152895 12.4510249159
6.29798000849 3.68338083649 15.5822111894
-1.58020810256 6.43644004023 12.5069376138
-1.59155160834 6.42939390132 15.6170202524
1.57676229838 6.4141883553 12.4756275623
1.63319176227 6.36986152038 15.5901788008
4.79648824658 6.43293252879 12.4512048301
4.74755103479 6.36741017957 15.5826799291
1.6115418047 2.74678063691 10.5151540413

因为要将MoS2上面的Ag原子穿透到下层，所以Ag的坐标变化幅度大，在使用dist.pl的时候，返回值为5.91，然后使用idpp插入了5个image，INCAR文件如下：
ISPIN  =  1          (Non-Spin polarised DFT)
ENCUT  =  450       (Cut-off energy for plane wave basis set, in eV)
PREC =  Normal    (Precision level)
LWAVE  = .FALSE.       (Write WAVECAR or not)
LCHARG = .FALSE.       (Write CHGCAR or not)
IVDW = 11

NCORE = 5
# LVTOT  = .TRUE.    (Write total electrostatic potential into LOCPOT or not)
# LVHAR  = .TRUE.    (Write ionic + Hartree electrostatic potential into LOCPOT or not)
# NELECT =          (No. of electrons: charged cells; be careful)
# LPLANE = .TRUE.    (Real space distribution; supercells)
# NPAR = 4          (Max is no. nodes; don't set for hybrids)
# Nwrite = 2          (Medium-level output)
# KPAR = 2          (Divides k-grid into separate groups)
# NGX = 500       (FFT grid mesh density for nice charge/potential plots)
# NGY = 500       (FFT grid mesh density for nice charge/potential plots)
# NGZ = 500       (FFT grid mesh density for nice charge/potential plots)

Electronic Relaxation
ISMEAR =  0          (Gaussian smearing; metals:1)
SIGMA  =  0.05       (Smearing value in eV; metals:0.2)
NELM =  90          (Max electronic SCF steps)
NELMIN =  6          (Min electronic SCF steps)
EDIFF  =  1E-04       (SCF energy convergence; in eV)
# GGA  =  PS          (PBEsol exchange-correlation)

Ionic Relaxation
NSW =  200       (Max ionic steps)
IBRION =  3          (Algorithm: 0-MD; 1-Quasi-New; 2-CG)
POTIM = 0
LOPT = 3
LCILMB = .T.
IMAGES = 5
ISIF =  2          (Stress/relaxation: 2-Ions, 3-Shape/Ions/V, 4-Shape/Ions)
EDIFFG = -2E-01       (Ionic convergence; eV/AA)
# ISYM =  2          (Symmetry: 0=none; 2=GGA; 3=hybrids)

KPOINT使用的是4*4*1
提交任务后使用nebef.pl查看，返回值如下：
0       0.000000    -196.318900       0.000000
1       11.825393    -189.865700       6.453200
2       40.745490    -164.847500       31.471400
3    158.903525    -129.406100       66.912800
4    146.805865    -151.150500       45.168400
5       14.495393    -191.094900       5.224000
6       0.000000    -194.817100       1.501800

发现原子受力巨大，然后查看.out文件，发现从第一步开始能量就没有变过，均为1 F= -.18987846E+03 E0= -.18986577E+03
我想问各位帮小弟看看是哪里出了问题，感激不尽！

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