KERNEL TRUNCATION/FACTOR

KERNEL_TRUNCATION/FACTOR = real 

Default: KERNEL_TRUNCATION/FACTOR	= $\sqrt{3}$	if KERNEL_TRUNCATION/IDIMENSIONALITY = 0
	= 1	if KERNEL_TRUNCATION/IDIMENSIONALITY = 2

Description: KERNEL_TRUNCATION/FACTOR determines the spatial extent of the truncated Coulomb interaction relative to the full cell dimension along the truncation direction.

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This tag defines the cutoff distance of the Coulomb kernel truncation boundary. It is expressed as a fraction of the simulation cell length along the truncated axis (e.g., the surface normal for 2D systems).

For example, when truncating along z, setting KERNEL_TRUNCATION/FACTOR = 0.5 ensures that electrostatic interactions only occur up to half the cell length in the z-direction, effectively centering the truncated region around the middle of the slab or molecule.

Mind: KERNEL_TRUNCATION/LTRUNCATE must be set to .TRUE. for KERNEL_TRUNCATION/FACTOR to take effect.

Example

KERNEL_TRUNCATION {
     LTRUNCATE       = T
     IDIMENSIONALITY = 2
     FACTOR          = 0.5
}

This corresponds to truncation along the surface normal (z-direction), keeping interactions within half of the cell length in z.

Related tags and articles

KERNEL_TRUNCATION/LTRUNCATE, KERNEL_TRUNCATION/IDIMENSIONALITY, KERNEL_TRUNCATION/LCOARSEN, KERNEL_TRUNCATION/IPAD, KERNEL_TRUNCATION/ISURFACE