Very strong oscillation during convergence

Message

tilak · #1 Post by **tilak** » Fri Feb 21, 2014 8:12 am

Dear Admin, for one of my layer-model system, during normal scf run, I have seen very strong oscillation. As a result, you can also see the grep TOTEN value from the OUTCAR also oscillates.

If needed, I can send the POSCAR file.

Thanks
Tilak

free energy TOTEN = -333.34215410 eV
free energy TOTEN = -333.34720513 eV
free energy TOTEN = -333.34165857 eV
free energy TOTEN = -333.34315801 eV
free energy TOTEN = -333.34494013 eV
free energy TOTEN = -333.34665447 eV
free energy TOTEN = -333.34880934 eV
free energy TOTEN = -333.35091287 eV
free energy TOTEN = -333.35279009 eV
free energy TOTEN = -333.35431444 eV
free energy TOTEN = -333.35077485 eV
free energy TOTEN = -333.35549407 eV
free energy TOTEN = -333.35412996 eV
free energy TOTEN = -384284.11367268 eV
free energy TOTEN = -11531793.74568559 eV
free energy TOTEN = -534042.50487614 eV
free energy TOTEN = -4362914.00945997 eV
free energy TOTEN = -8488045.16838749 eV
free energy TOTEN = -17274452.47895679 eV
free energy TOTEN = -21560598.88305885 eV
free energy TOTEN = -35000078.07141138 eV
free energy TOTEN = -23349767.48159637 eV
free energy TOTEN = -36572353.83856550 eV
free energy TOTEN = -48080784.54740475 eV
free energy TOTEN = -58265675.67367712 eV
free energy TOTEN = -57892867.33770861 eV
free energy TOTEN = -44938092.65478924 eV
free energy TOTEN = -40964502.28391489 eV
free energy TOTEN = -79474815.61736687 eV
free energy TOTEN = -49510007.17811391 eV
free energy TOTEN = -35923939.88103947 eV

tilak · #2 Post by **tilak** » Sun Mar 09, 2014 1:34 pm

Hello, for another system I do have similar problem:
-------------
free energy TOTEN = -341.61766657 eV
free energy TOTEN = -341.63815253 eV
free energy TOTEN = -341.66318224 eV
free energy TOTEN = -341.66642022 eV
free energy TOTEN = -341.74450778 eV
free energy TOTEN = -216755.88396179 eV
free energy TOTEN = -20015773.64972186 eV
free energy TOTEN = -37993100.19353102 eV
free energy TOTEN = ****************** eV
free energy TOTEN = -16644634.28614424 eV
free energy TOTEN = -49079576.82319330 eV
-----------------------
In both cases, initially have created CHG, CHGCAR & WAVECAR using LREAL=Auto and PREC=N, with ISTART=0, ICHARG=2.

And then in the second step, once I switch to the LREAL=.F. & PREC=A and ISTART=1 & ICHARG=1, NBANDS doubled choice. I saw such effect!

Thank you very much for your any comment/s,
Tilak