This is part of the colvar module

This is a fake colvar container used by cltools or various other actions and just support input and period definition

The atoms involved can be specified using

ATOMS

the fake atom index, a number is enough. For more information on how to specify lists of atoms see Groups and Virtual Atoms

Compulsory keywords

PERIODIC

if the output of your function is periodic then you should specify the periodicity of the function. If the output is not periodic you must state this using PERIODIC=NO,NO (one for the lower and the other for the upper boundary). For multicomponents then it is PERIODIC=mincomp1,maxcomp1,mincomp2,maxcomp2 etc

Options

NUMERICAL_DERIVATIVES

( default=off ) calculate the derivatives for these quantities numerically

NOPBC

( default=off ) ignore the periodic boundary conditions when calculating distances

COMPONENTS

additional componnets that this variable is supposed to have. Periodicity is ruled by PERIODIC keyword

Examples

FAKE ATOMS=1 PERIODIC=-3.14,3.14   LABEL=d2

(See also PRINT).