NEB converge problem

[gump_813]

Hi, I am running a NEB calculation on vasp about the O2 dissociation on Pt(111) surface.
But the calculation can not converge, after 2 NEB steps, the force of the first image will increase dramatically due to the near distance between the O atoms.
I use QM optimizer and set TIMESTEP to 0.01 which I think is a rather small value already. But the problem still happens. Here are my INCAR file and the
initial path. Can anybody do me a favor to have look at them, and figure out the problem? By the way, both ends are well converged. many thanks.

INCAR:
SYSTEM = PtO2TS
ISTART = 0
ICHARG = 2
LREAL = AUTO
ISIF = 2
ISPIN = 2
ENCUT = 400
ALGO=FAST
NSIM=4
EDIFFG = -0.01
NSW = 10
IBRION = 3
OPTIM = 0
ICHAIN = 0
IMAGES = 4
SPRING = -5
LCLIMB = .TRUE.
IOPT =3
MAXMOVE=0.1
TIMESTEP=0.01
ISMEAR = 1; SIGMA = 0.1
LPLANE = .TRUE.
NPAR = 8
LCHARG=.FALSE.

Intial Path:

18
F: 0.008060 ... E: 0
Pt -2.44459076250000 1.41138513500000 0.00000000000000
Pt 0.00000000000000 0.00000000000000 0.00000000000000
Pt 0.00000000000000 2.82277027000000 0.00000000000000
Pt 2.44459076250000 1.41138513500000 0.00000000000000
Pt -0.81486358424053 1.41138513500000 2.30478227247299
Pt 1.62972717825947 2.82277027000000 2.30478227247299
Pt -0.81486358424053 4.23415540500000 2.30478227247299
Pt -3.25945434674053 2.82277027000000 2.30478227247299
Pt -1.65357341033708 2.80909049276663 4.57620707945676
Pt 0.78822229928882 1.39055249682186 4.54606475260259
Pt 3.25405666923238 2.80280050955007 4.58884789470019
Pt 0.77970618146498 4.23000695342946 4.58626845174370
Pt 2.37949897163135 4.16860053621602 6.84331711915147
Pt -0.07481178562902 5.56232647331671 6.95551829653356
Pt -0.06106874056054 2.74974500611297 6.85802334952213
Pt -2.51805080281980 4.16880379679632 6.85922151894472
O 0.77721445271605 1.38211591071315 9.17002128673695
O 0.13403771908933 0.27360730834743 8.96293074221107
18
F: ... E: 101.818092
Pt -2.44459076250000 1.41138513500000 0.00000000000000
Pt 0.00000000000000 0.00000000000000 0.00000000000000
Pt 0.00000000000000 2.82277027000000 0.00000000000000
Pt 2.44459076250000 1.41138513500000 0.00000000000000
Pt -0.81486358424054 1.41138513500000 2.30478227247300
Pt 1.62972717825946 2.82277027000000 2.30478227247300
Pt -0.81486358424054 4.23415540500000 2.30478227247300
Pt -3.25945434674054 2.82277027000000 2.30478227247300
Pt -1.65084644360325 2.81536378038582 4.58947750384956
Pt 0.78952128754679 1.40169792262041 4.54658400461084
Pt 3.25110693600161 2.81377335980297 4.58081051828894
Pt 0.78469538233838 4.23437397591607 4.59752660167919
Pt 2.37840250897010 4.20615909680239 6.88109564393707
Pt -0.05749170796945 5.57488559489820 6.92759140854082
Pt -0.06296981328341 2.78879764571995 6.89286062823361
Pt -2.50100107422207 4.17779042668189 6.85055398646966
O 0.95395440653786 1.65944327377022 8.95112293365840
O -0.04950513286353 0.49035936487764 8.78545049803772
18
F: ... E: 101.818092
Pt -2.44459076250000 1.41138513500000 0.00000000000000
Pt 0.00000000000000 0.00000000000000 0.00000000000000
Pt 0.00000000000000 2.82277027000000 0.00000000000000
Pt 2.44459076250000 1.41138513500000 0.00000000000000
Pt -0.81486358424054 1.41138513500000 2.30478227247300
Pt 1.62972717825946 2.82277027000000 2.30478227247300
Pt -0.81486358424054 4.23415540500000 2.30478227247300
Pt -3.25945434674054 2.82277027000000 2.30478227247300
Pt -1.64811947686945 2.82163706800500 4.60274792824244
Pt 0.79082027580471 1.41284334841896 4.54710325661911
Pt 3.24815720277083 2.82474621005587 4.57277314187783
Pt 0.78968458321175 4.23874099840269 4.60878475161468
Pt 2.37730604630886 4.24371765738877 6.91887416872262
Pt -0.04017163030988 5.58744471647968 6.89966452054803
Pt -0.06487088600625 2.82785028532692 6.92769790694502
Pt -2.48395134562433 4.18677705656745 6.84188645399476
O 1.13069436035966 1.93677063682729 8.73222458057986
O -0.23304798481641 0.70711142140787 8.60797025386431
18
F: ... E: 101.818092
Pt -2.44459076250000 1.41138513500000 0.00000000000000
Pt 0.00000000000000 0.00000000000000 0.00000000000000
Pt 0.00000000000000 2.82277027000000 0.00000000000000
Pt 2.44459076250000 1.41138513500000 0.00000000000000
Pt -0.81486358424054 1.41138513500000 2.30478227247300
Pt 1.62972717825946 2.82277027000000 2.30478227247300
Pt -0.81486358424054 4.23415540500000 2.30478227247300
Pt -3.25945434674054 2.82277027000000 2.30478227247300
Pt -1.64539251013565 2.82791035562418 4.61601835263533
Pt 0.79211926406264 1.42398877421751 4.54762250862737
Pt 3.24520746954004 2.83571906030877 4.56473576546658
Pt 0.79467378408512 4.24310802088932 4.62004290155014
Pt -2.51297194135238 1.45850594797516 6.95665269350815
Pt -0.02285155265030 5.60000383806115 6.87173763255526
Pt -0.06677195872909 2.86690292493388 6.96253518565643
Pt -2.46690161702659 4.19576368645301 6.83321892151984
O 1.30743431418146 2.21409799988436 8.51332622750132
O -0.41659083676929 0.92386347793810 8.43049000969092
18
F: ... E: 101.818092
Pt -2.44459076250000 1.41138513500000 0.00000000000000
Pt 0.00000000000000 0.00000000000000 0.00000000000000
Pt 0.00000000000000 2.82277027000000 0.00000000000000
Pt 2.44459076250000 1.41138513500000 0.00000000000000
Pt -0.81486358424054 1.41138513500000 2.30478227247300
Pt 1.62972717825946 2.82277027000000 2.30478227247300
Pt -0.81486358424054 4.23415540500000 2.30478227247300
Pt -3.25945434674054 2.82277027000000 2.30478227247300
Pt -1.64266554340184 2.83418364324336 4.62928877702823
Pt 0.79341825232056 1.43513420001606 4.54814176063564
Pt 3.24225773630927 2.84669191056167 4.55669838905530
Pt 0.79966298495850 4.24747504337594 4.63130105148563
Pt -2.51406840401362 1.49606450856154 6.99443121829371
Pt -0.00553147499072 5.61256295964263 6.84381074456249
Pt -0.06867303145198 2.90595556454086 6.99737246436783
Pt -2.44985188842885 4.20475031633857 6.82455138904491
O 1.48417426800326 2.49142536294142 8.29442787442278
O -0.60013368872217 1.14061553446833 8.25300976551751
18
F: 0.005919 ... E: -1.548053
Pt -2.44459076250000 1.41138513500000 0.00000000000000
Pt 0.00000000000000 0.00000000000000 0.00000000000000
Pt 0.00000000000000 2.82277027000000 0.00000000000000
Pt 2.44459076250000 1.41138513500000 0.00000000000000
Pt -0.81486358424053 1.41138513500000 2.30478227247299
Pt 1.62972717825947 2.82277027000000 2.30478227247299
Pt -0.81486358424053 4.23415540500000 2.30478227247299
Pt -3.25945434674053 2.82277027000000 2.30478227247299
Pt -1.63993857666800 2.84045693086256 4.64255920142101
Pt 0.79471724057852 1.44627962581459 4.54866101264425
Pt 3.23930800307852 2.85766476081459 4.54866101264425
Pt 0.80465218583200 4.25184206586256 4.64255920142101
Pt -2.51516486667483 1.53362306914785 7.03220974307919
Pt 0.01178860266892 5.62512208122415 6.81588385656983
Pt -0.07057410417487 2.94500820414783 7.03220974307919
Pt -2.43280215983108 4.21373694622415 6.81588385656983
O 1.66091422182496 2.76875272599850 8.07552952134429
O -0.78367654067500 1.35736759099852 8.07552952134429

[dano]

There seems to be a typo in you INCAR

OPTIM = 0

should be
POTIM=0

This will make sure you are not taking two steps for every force

Dan

[gump_813]

Oh my god!!

Thank you for helping me out.

any other problems?