DOS run warning to be worried or not?
Posted: Tue Feb 01, 2011 1:29 am
Hi Admin,
I came to notice a warning in OUTCAR file while running a spin-polarized PBE DOS job statically reading in the charges from CHARGCAR, obtained through a prior single-point run with (higher K-mesh, say 15*15*15 gamma-centred, and added extra empty bands), and both single-pt runs were performed with Tetrahedron intergration methods with Bloechl's correction on the equilibrium geometry obtained through optimization of internal coordinates and cell shape (ISIF =4, ediff=1e-8, ediffg= -1e-3) with 9*9*9 mesh and with the equlibrium volume that was obtained through B-M EOS fit at higher cut-offs, 750eV. All geom opt and single-point runs are done with 520 eV. Eq vol, cell parameters and internal co-ordinates are in excellent agreement with the experimental and previously reported PBE data. And eq cell geometry had "0" external pressure, either, (re-checked with higher cutoffs, as well). However, during DOS run with LORBIT = 12, the OUTCAR (VASP 2.5.
is printing the followig warning:
" use gradient corrections
WARNING: stress and forces are not correct
(second derivative of E(xc) not defined)
use of overlap-Matrix (Vanderbilt PP)
Fermi weights with tetrahedron method with Bloechl corrections"
Could you please throw some light to this issue? Why does it warn saying stress & forces are not correct?
Your co-operation will be highly appreciated and acknowleged. Thanks in advance.
Best regards,
Sankh
I came to notice a warning in OUTCAR file while running a spin-polarized PBE DOS job statically reading in the charges from CHARGCAR, obtained through a prior single-point run with (higher K-mesh, say 15*15*15 gamma-centred, and added extra empty bands), and both single-pt runs were performed with Tetrahedron intergration methods with Bloechl's correction on the equilibrium geometry obtained through optimization of internal coordinates and cell shape (ISIF =4, ediff=1e-8, ediffg= -1e-3) with 9*9*9 mesh and with the equlibrium volume that was obtained through B-M EOS fit at higher cut-offs, 750eV. All geom opt and single-point runs are done with 520 eV. Eq vol, cell parameters and internal co-ordinates are in excellent agreement with the experimental and previously reported PBE data. And eq cell geometry had "0" external pressure, either, (re-checked with higher cutoffs, as well). However, during DOS run with LORBIT = 12, the OUTCAR (VASP 2.5.
is printing the followig warning:" use gradient corrections
WARNING: stress and forces are not correct
(second derivative of E(xc) not defined)
use of overlap-Matrix (Vanderbilt PP)
Fermi weights with tetrahedron method with Bloechl corrections"
Could you please throw some light to this issue? Why does it warn saying stress & forces are not correct?
Your co-operation will be highly appreciated and acknowleged. Thanks in advance.
Best regards,
Sankh