# DISTANCE_FUNCTION

Section to define functions between two distances as collective variables. The function is defined as d1+coeff*d2 [Edit on GitHub]

Subsections

- POINT

## Keywords

- ATOMS

- COEFFICIENT

- PBC

## Keyword descriptions

ATOMS: integer[4]

  Aliases: POINTS

  Usage: ATOMS {integer} {integer} {integer} {integer}

  Specifies the indexes of atoms/points for the two bonds d1=(1-2) d2=(3-4). [Edit on GitHub]

COEFFICIENT: real

  Usage: 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 [Edit on GitHub]

PBC: logical = T

  Lone keyword: `T`

  Usage: PBC

  Whether periodic boundary conditions should be applied on the atomic position before computing the colvar or not. [Edit on GitHub]