KERNEL TRUNCATION/FACTOR: Difference between revisions
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LTRUNCATE = T | LTRUNCATE = T | ||
IDIMENSIONALITY = 2 | IDIMENSIONALITY = 2 | ||
ISURFACE = 3 | |||
IPAD = 2 | |||
FACTOR = 1 | |||
} | |||
</pre> | |||
In this case an additional empty cell is added along the z direciton as padding. The coulomb interaction is truncated beyond a z length. This ensures maximum usage of the simulation box. | |||
<pre> | |||
KERNEL_TRUNCATION { | |||
LTRUNCATE = T | |||
IDIMENSIONALITY = 2 | |||
ISURFACE = 3 | |||
IPAD = 1 | |||
FACTOR = 0.5 | FACTOR = 0.5 | ||
} | } | ||
</pre> | </pre> | ||
This corresponds to | This setup corresponds to truncating the Coulomb interaction along the surface normal (z-direction) for a 2D material, using no vacuum padding and a truncation length of z/2. In this case, half of the simulation box is effectively unused, but the algorithm remains simpler. This configuration can be useful for debugging purposes. | ||
== Related tags and articles == | == Related tags and articles == | ||
Revision as of 08:22, 14 October 2025
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[1].
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).
Mind: KERNEL_TRUNCATION/LTRUNCATE must be set to .TRUE. for KERNEL_TRUNCATION/FACTOR to take effect.
|
Example
KERNEL_TRUNCATION {
LTRUNCATE = T
IDIMENSIONALITY = 2
ISURFACE = 3
IPAD = 2
FACTOR = 1
}
In this case an additional empty cell is added along the z direciton as padding. The coulomb interaction is truncated beyond a z length. This ensures maximum usage of the simulation box.
KERNEL_TRUNCATION {
LTRUNCATE = T
IDIMENSIONALITY = 2
ISURFACE = 3
IPAD = 1
FACTOR = 0.5
}
This setup corresponds to truncating the Coulomb interaction along the surface normal (z-direction) for a 2D material, using no vacuum padding and a truncation length of z/2. In this case, half of the simulation box is effectively unused, but the algorithm remains simpler. This configuration can be useful for debugging purposes.
Related tags and articles
KERNEL_TRUNCATION/LTRUNCATE, KERNEL_TRUNCATION/IDIMENSIONALITY, KERNEL_TRUNCATION/LCOARSEN, KERNEL_TRUNCATION/IPAD, KERNEL_TRUNCATION/ISURFACE