My Community

Hello guys,
I am running Simulated Annealing calculations by VASP for
metal clusters.
One job went wrong.
The energy of system is typically -123. eV,
but after roughly 2000 SA iterations the energy jumped to around
-80.0 eV.
I redid calculation several times and this problem
kept occuring.
Would you please help me on this?
Thanks,
Min

2317 T= 3007. E= -.11851786E+03 F= -.12318169E+03 E0= -.12318353E+03 EK= 0.46638E+01 SP= 0.00E+00 SK= 0.00E+00 mag= -6.0
55
2318 T= 3007. E= -.11840673E+03 F= -.12307050E+03 E0= -.12307503E+03 EK= 0.46638E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 0.0
56
2319 T= 3007. E= -.11847018E+03 F= -.12313389E+03 E0= -.12313744E+03 EK= 0.46637E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 5.9
24
2320 T= 3007. E= -.80377280E+02 F= -.85040936E+02 E0= -.85043985E+02 EK= 0.46637E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 6.0
22
2321 T= 3007. E= -.80474482E+02 F= -.85138082E+02 E0= -.85141019E+02 EK= 0.46636E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 1.9
31
2322 T= 3007. E= -.79892470E+02 F= -.84556013E+02 E0= -.84555316E+02 EK= 0.46635E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 0.3
97
2323 T= 3007. E= -.80338530E+02 F= -.85002017E+02 E0= -.85003143E+02 EK= 0.46635E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 0.1
89
2324 T= 3006. E= -.80340222E+02 F= -.85003653E+02 E0= -.85006526E+02 EK= 0.46634E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 0.1
27
2325 T= 3006. E= -.79969587E+02 F= -.84632960E+02 E0= -.84636508E+02 EK= 0.46634E+01 SP= 0.00E+00 SK= 0.00E+00 mag= -0.0
33
2326 T= 3006. E= -.80319931E+02 F= -.84983249E+02 E0= -.84986890E+02 EK= 0.46633E+01 SP= 0.00E+00 SK= 0.00E+00 mag= 1.9
99

the information you provide is too little to give any specific hint. first of all please check which contribution to the total energy is (mainly) responsible for that drop.

Below are energy components when jump happened:

Just Before jump (Normal energy);
Free energy of the ion-electron system (eV)
---------------------------------------------------
alpha Z PSCENC = 84.65511691
Ewald energy TEWEN = 16393.50598077
-1/2 Hartree DENC = -30627.10871066
-V(xc)+E(xc) XCENC = 469.18936192
PAW double counting = 12654.17126022 -12444.94843984
entropy T*S EENTRO = 0.00057981
eigenvalues EBANDS = -3329.57618207
atomic energy EATOM = 16695.13615294
---------------------------------------------------
free energy TOTEN = -104.97487998 eV

energy without entropy = -104.97545979 energy(sigma->0) = -104.97507325

ENERGIE OF THE ELECTRON-ION-THERMOSTAT SYSTEM (eV)
---------------------------------------------------
% ion-electron TOTEN = -104.974316 see above
kinetic Energy EKIN = 4.560158 (temperature 2939.90 K)
nose potential ES = 0.000000
nose kinetic EPS = 0.000000
---------------------------------------------------
total energy ETOTAL = -100.414158 eV

maximum distance moved by ions : 0.18E-02

WAVPRE: VPU time 0.19: CPU time 0.19
FEWALD: VPU time 0.00: CPU time 0.00

real space projection operators:
total allocation : 3490.03 KBytes
max/ min on nodes : 3490.03 3490.03

ORTHCH: VPU time 0.22: CPU time 0.22
Prediction of Wavefunctions ALPHA= 2.058 BETA=-1.059
LOOP+: VPU time 57.11: CPU time 57.24



Just after the jump:
Free energy of the ion-electron system (eV)
---------------------------------------------------
alpha Z PSCENC = 84.65511691
Ewald energy TEWEN = 16441.94892287
-1/2 Hartree DENC = -30635.85880420
-V(xc)+E(xc) XCENC = 469.97581222
PAW double counting = 12638.98807302 -12429.07480595
entropy T*S EENTRO = 0.00064834
eigenvalues EBANDS = -3301.75541432
atomic energy EATOM = 16695.13615294
---------------------------------------------------
free energy TOTEN = -35.98429818 eV

energy without entropy = -35.98494652 energy(sigma->0) = -35.98451429

ENERGIE OF THE ELECTRON-ION-THERMOSTAT SYSTEM (eV)
---------------------------------------------------
% ion-electron TOTEN = -35.983602 see above
kinetic Energy EKIN = 4.560097 (temperature 2939.86 K)
nose potential ES = 0.000000
nose kinetic EPS = 0.000000
---------------------------------------------------
total energy ETOTAL = -31.423505 eV

maximum distance moved by ions : 0.18E-02

WAVPRE: VPU time 0.19: CPU time 0.20
FEWALD: VPU time 0.00: CPU time 0.00

real space projection operators:
total allocation : 3493.41 KBytes
max/ min on nodes : 3493.41 3493.41

ORTHCH: VPU time 0.22: CPU time 0.22
Prediction of Wavefunctions ALPHA= 1.934 BETA=-0.937
LOOP+: VPU time 409.34: CPU time 412.06

Sorry forgot to mention,
This happened only for calculations for clusters formed by Mo and W .

the jump in the total energy is almost completely due to the Ewald energy and band energy contributiions. Please check (eg in XDATCAR) if there was a significant change in the geometry at this step. It may also help to choose a 'safe' setting of ALGO (N or F, in case you had set it to V).

These are strucutres just before jump and right after jump
There is almost no change.
The structures are elongated and one atom in that cluster
is bonded to only one of the others.
Min

cubic
1.
16.0000000000000000 0.0000000000000000 0.0000000000000000
0.0000000000000000 16.0000000000000000 0.0000000000000000
0.0000000000000000 0.0000000000000000 16.0000000000000000
13
Direct
0.36416979 0.60769751 0.33879314
0.29964072 0.49333682 0.40295735
0.36972510 0.67297024 0.46308800
0.52313893 0.43519420 0.63112852
0.54646622 0.61656899 0.60356426
0.47955230 0.52101985 0.39656915
0.64213655 0.50843798 0.57437631
0.44734171 0.39845798 0.47247493
0.55516097 0.29661411 0.58369330
0.58014277 0.62009905 0.46511260
0.58580561 0.42247013 0.46077590
0.42792185 0.55909965 0.54551645
0.67879747 0.34803350 0.56195009


cubic
1.
16.0000000000000000 0.0000000000000000 0.0000000000000000
0.0000000000000000 16.0000000000000000 0.0000000000000000
0.0000000000000000 0.0000000000000000 16.0000000000000000
13
Direct
0.36366113 0.60728461 0.33795423
0.29972942 0.49250759 0.40255797
0.36946487 0.67250852 0.46320625
0.52382216 0.43590460 0.63135340
0.54561329 0.61765278 0.60244666
0.47992135 0.52114381 0.39678429
0.64177458 0.50745781 0.57366569
0.44759205 0.39828926 0.47237947
0.55630159 0.29739301 0.58400401
0.57924524 0.61929189 0.46549694
0.58575749 0.42244018 0.46134553
0.42789252 0.55937124 0.54653260
0.67922431 0.34875472 0.56227296