Hello everyone,

I am currently working on BaTiO₃ surfaces (TiO₂-terminated, BaO-terminated, and stoichiometric) and I have already performed relaxation runs for each surface using the following INCAR file:

SYSTEM = BaTiO3_surface

IBRION = 2

NSW = 100

ENCUT = 550

ISMEAR = 1

SIGMA = 0.2

ISIF = 2

LREAL = Auto

PREC = High

ALGO = Fast

NELMIN = 4

EDIFF = 1E-6

EDIFFG = -0.01

NELMDL = -4

NGX = 50

NGY = 50

NGZ = 570

GGA = Default

Now, I am preparing displacement runs (uniaxial, biaxial, and shear strains) on these relaxed slabs in order to extract piezoelectric constants.

Should I add the following dipole correction lines to my INCAR for the displacement runs, even though I am not adding any external charge to the system?

LDIPOL = .TRUE.

IDIPOL = 3

DIPOL = x y z # (center of the slab)

I did not include these dipole terms in my relaxation runs. Would you recommend adding them now for the displacement runs?

Any advice or references would be greatly appreciated!