LDIPOL

LDIPOL = .TRUE. | .FALSE.
Default: LDIPOL = .FALSE. 

Description: LDIPOL switches on dipole-dipole interaction correction to the potential.

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Due to the periodic boundary conditions, not only the total energy converges slowly with respect to the size of the supercell, but also the potential and the forces are affected by finite size errors. This effect can be counterbalanced by setting LDIPOL=.TRUE. (dipole corrections) and/or LMONO=.TRUE. (monopole corrections) in the INCAR file. For LDIPOL=.TRUE.,a linear and for LMONO=.TRUE., a quadratic electrostatic potential is added to the local potential, correcting the errors introduced by the periodic boundary conditions. This is in the spirit of Neugebauer et al. (but more general and the total energy has been correctly implemented right away). The biggest advantage of this mode is that leading errors in the forces are corrected, and that the work-function can be evaluated for asymmetric slabs. The disadvantage is that the convergence to the electronic groundstate might slow down considerably (i.e., more electronic iterations might be required to obtain the required precision). It is recommended to use this mode only after pre-converging the orbitals without the LDIPOL flag, and the center of charge should be set in the INCAR file (DIPOL= center of mass). The user must also ensure that the cell is sufficiently large to determine the dipole moment with sufficient accuracy. If the cell is too small, charge might swap through the vacuum, causing very slow convergence (often convergence improves with the size of the supercell).

Related Tags and Sections

Monopole Dipole and Quadrupole corrections, NELECT, EPSILON, IDIPOL, DIPOL, LMONO, EFIELD

Example Calculations using this Tag

partial DOS of CO on Ni 111 surface

References

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