Section DISTANCE_FUNCTION

• Section to define functions between two distances as collective variables. The function is defined as d1+coeff*d2

• Section path: CP2K_INPUT / FORCE_EVAL / SUBSYS / COLVAR / REACTION_PATH / COLVAR / DISTANCE_FUNCTION

• This section cannot be repeated and cannot be optional.

• Subsections

  • POINT

• Keywords

  • ATOMS
  • COEFFICIENT
  • PBC

• Keyword descriptions

  ATOMS
  	ATOMS {INTEGER} {INTEGER} {INTEGER} {INTEGER}
  	Specifies the indexes of atoms/points for the two bonds d1=(1-2) d2=(3-4).
  	This required keyword cannot be repeated and it expects precisely 4 integers.
  	Alias names for this keyword: POINTS

  COEFFICIENT
  	COEFFICIENT {REAL}
  	Specifies the coefficient in the function for the constraint. -1.0 has to be used for distance difference, 1.0 for distance addition
  	This required keyword cannot be repeated and it expects precisely one real.

  PBC
  	PBC
  	Whether periodic boundary conditions should be applied on the atomic position before computing the colvar or not.
  	This optional keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .FALSE.
  	Default value: .TRUE.