KERNEL TRUNCATION/LTRUNCATE

KERNEL_TRUNCATION/LTRUNCATE_COULOMB_KERNEL = .True. | .False.
Default: KERNEL_TRUNCATION/LTRUNCATE_COULOMB_KERNEL = .False. 

Description: KERNEL_TRUNCATION/LTRUNCATE_COULOMB_KERNEL truncates the coulomb kernel to remove electrostatic interactions along non-periodic dimensions

---

Setting KERNEL_TRUNCATION/LTRUNCATE_COULOMB_KERNEL to .True. switches on coulomb kernel truncation methods. These methods removes interactions with periodic replicas in non-periodic directions, i.e. along the surface normal for 2D materials and along all directions for 0D systems such as atoms and molecules.

Mind: This tag acts as a "super-tag", i.e. unless this tag is switched on further options in KERNEL_TRUNCATION will be ignored.

Default settings

The following default settings are assumed when setting KERNEL_TRUNCATION/LTRUNCATE_COULOMB_KERNEL to .True.,

  KERNEL_TRUNCATION {
        LTRUNCATE_COULOMB_KERNEL = T
        IDIMENIONALITY_CUTOFF    = 0
        LCOARSEN_BEFORE_PAD      = T
  }

which translates to 0D coulomb truncation which is suitable for a molecule using the coarsen before pad strategy [cite]. Detailed information is available on the respective pages of the INCAR tags.