This is part of the colvar module

Return one or more constant quantities with or without derivatives.

Useful in combination with functions that takes in input constants or parameters.

Description of components

By default this Action calculates the following quantities. These quantities can be referenced elsewhere in the input by using this Action's label followed by a dot and the name of the quantity required from the list below.

Quantity	Description
v	the # value

Options

NOPBC	( default=off ) ignore the periodic boundary conditions when calculating distances
NODERIV	( default=off ) Set to TRUE if you want values without derivatives.
VALUES	The values of the constants
VALUE	The value of the constant

Examples

The following input instructs plumed to compute the distance between atoms 1 and 2. If this distance is between 1.0 and 2.0, it is printed. If it is lower than 1.0 (larger than 2.0), 1.0 (2.0) is printed

cn: CONSTANT VALUES=1.0,2.0
dis: DISTANCE ATOMS=1,2
sss: SORT ARG=cn.v-0,dis,cn.v-1
PRINT ARG=sss.2

In case you want to pass a single value you can use VALUE:

cn: CONSTANT VALUE=1.0
dis: DISTANCE ATOMS=1,2
sss: SORT ARG=cn,dis
PRINT ARG=sss.1