# Optical properties without LOPTICS tag

I have performed some calculations for a 2D-monolayer using VASP. I run DOS calculations without LOPTICS = .TRUE. I found that when I run the vaspkit, I got the files for optical properties. Could someone please explain to me, if we are getting the files for optical properties, then how reliable are these files?

INCAR

ISTART   = 1
# ICHARG   = 11
# ISYM = 0
PREC     = Accurate
ENCUT    = 550
ISMEAR   = 0
SIGMA    = 0.1
LREAL    = .FALSE.
LWAVE    = .TRUE.
LCHARG   = .TRUE.
EDIFF   = 1e-6
EDIFFG  = -0.02
NSW     = 0
LORBIT  = 12
NEDOS   = 5000
LHFCALC= T
AEXX   =  0.25 HFSCREEN= 0.2
ALGO   =  ALL
TIME   =  0.4

• The comment discussion has been moved to chat
– Tyberius
Aug 27, 2021 at 13:53

• When you open the LHFCALC tag, the DFT hybrid functional type dielectric function is calculated. All the output files you obtain are calculated by VASPKIT using this dielectric function.