The CP2K project : input section FIXED_ATOMS

Section FIXED_ATOMS

Index of all sections. This section is located at __ROOT__%MOTION%CONSTRAINT%FIXED_ATOMS.

This section is used to constraint the overall atomic position (X,Y,Z). In case a restraint is specified the value of the TARGET is considered to be the value of the coordinates at the beginning of the run or alternatively the corresponding value in the section: FIX_ATOM_RESTART. This section can be repeated and can not be optional.

Subsections

Section keywords

Keyword descriptions

COMPONENTS_TO_FIX
FIXED_ATOMS (x|y|z|xy|xz|yz|xyz)
Specify which components (X,Y,Z or combinations) of the atoms specified in the sectionwill be constrained/restrained.
This optional keyword expects a keyword. Default value: XYZ
valid keywords:
  • X: Fix only X component
  • Y: Fix only Y component
  • Z: Fix only Z component
  • XY: Fix X-Y components
  • XZ: Fix X-Z components
  • YZ: Fix Y-Z components
  • XYZ: Fix the full components of the atomic position.
LIST
LIST {integer} {integer} .. {integer}
Specifies a list of atoms to freeze.
This required keyword expects a list of integers, and may repeat
MOLNAME
MOLNAME WAT MEOH
Specifies the name of the molecule to fix
This required keyword expects a list of words, and may repeat
variants: SEGNAME
MM_SUBSYS
MM_SUBSYS (NONE|ATOMIC|MOLECULAR)
In a QM/MM run all MM atoms are fixed according to the argument.
This required keyword expects a keyword. Default value: NONE
valid keywords:
  • NONE: fix nothing
  • ATOMIC: only the MM atoms itself
  • MOLECULAR: the full molecule/residue that contains a MM atom (i.e. some QM atoms might be fixed as well)
variants: PROTEIN
QM_SUBSYS
QM_SUBSYS (NONE|ATOMIC|MOLECULAR)
In a QM/MM run all QM atoms are fixed according to the argument.
This required keyword expects a keyword. Default value: NONE
valid keywords:
  • NONE: fix nothing
  • ATOMIC: only the QM atoms itself
  • MOLECULAR: the full molecule/residue that contains a QM atom (i.e. some MM atoms might be fixed as well)
EXCLUDE_QM
EXCLUDE_QM
Does not apply the constraint to the QM region within a QM/MM calculation. This keyword is active only together with MOLNAME
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
EXCLUDE_MM
EXCLUDE_MM
Does not apply the constraint to the MM region within a QM/MM calculation. This keyword is active only together with MOLNAME
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F


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