QCUT, ENMAX, ENCUT

[bandy]

How I can fix ENCUT in INCAR?
If I do "grep ENMAX POTCAR"
I get
ENMAX = 270.000; ENMIN = 191.312 eV (for P)
ENMAX = 250.000; ENMIN = 200.000 eV (H Z=1.0)
ENMAX = 250.000; ENMIN = 200.000 eV (H Z= 0.75)


I am getting the following error message with ENCUT=350 in INCAR:

-----------------------------------------------------------------------------
| |
| ADVICE TO THIS USER RUNNING 'VASP/VAMP' (HEAR YOUR MASTER'S VOICE ...): |
| |
| One real space projector is optimized for |
| E = 449.69, eV but you are using a cutoff of |
| ENMAX= 350.00 eV ( QCUT= 5.07 a.u.) |
| This makes no sense reoptimize the projector |
| with the a.u. value given above |
| |
-----------------------------------------------------------------------------

I checked in the code (tutor.F) also the link
http://www.people.cornell.edu/pages/jf2 ... seudo-real


IF (LIO.AND. TOPIC(1:LTOPIC)=='WRONG OPTIMZATION REAL-SPACE') THEN
WRITE(IU,'(A)') '| One real space projector is optimized' &
& //' for |'
WRITE(IU,'(A,F10.2,A)') &
& '| E =',RDAT(1),', eV but you are using a ' &
& //' cutoff of |'
WRITE(IU,'(A,F10.2,A,F10.2,A)') &
& '| ENMAX=',RDAT(2),' eV ( QCUT=',RDAT(3), &
& ' a.u.) |'
WRITE(IU,'(A)') '| This makes no sense reoptimize the ' &
& //' projector |'
WRITE(IU,'(A)') '| with the a.u. value given above ' &
& //' |'
ENDIF

LREAL=Auto does not rectify the problem.

From the manual,

"If real space optimization should be done, QCUT must be set to the energy cutoff, which will be used in VAMP. Anyway here QCUT has to be supplied in 1/a.u. (i.e. as a inverse length) and can be calculated from the cutoff energy using the formula"

QCUT = SQRT(ENCUT/13.6058) 1Ry=13.6058 eV

for ENCUT=350, QCUT=5.07

for QCUT=5.749, ENCUT= 5.749*5.749*13.6058=449.6853 eV

If I do "grep QCUT POTCAR" I get

QCUT = -4.330; QGAM = 8.660 optimization parameters
QCUT = -5.749; QGAM = 11.498 optimization parameters


Thus do I need to set QCUT=-5.749?

All files are in http://bandy46.tripod.com/INCAR.txt, POTCAR.txt, POSCAR.txt, KPOINTS.txt

Thanks for any help

[support_vasp]

Hi,

We're sorry that we didn’t answer your question. This does not live up to the quality of support that we aim to provide. The team has since expanded. If we can still help with your problem, please ask again in a new post, linking to this one, and we will answer as quickly as possible.

Best wishes,

VASP