This is part of the isdb module

Defines a variable (of the type double) inside the PLUMED code that can be used and modified by other actions.

A SELECTOR can be used for example to activate or modify a bias based on its current value.

Examples

A typical example is the simulated-tempering like approach activated by RESCALE. In this example the total potential energy of the system is scaled by a parameter defined on a grid of dimension NBIN in the range from 1 to MAX_RESCALE. The value of the scaling parameter is determined by the current value of the SELECTOR GAMMA. The value of the SELECTOR is updated by a MC protocol inside the RESCALE class. A well-tempered metadynamics potential is used to enhance sampling in the SELECTOR space.

Click on the labels of the actions for more information on what each action computes

ene: ENERGY The ENERGY action with label ene calculates a single scalar value
SELECTOR NAMEcompulsory keyword 
name of the SELECTOR 
=GAMMA VALUEcompulsory keyword 
set (initial) value of the SELECTOR 
=0 The SELECTOR action with label 
res: RESCALE ...
   ARGcompulsory keyword 
the labels of the scalars on which the bias will act 
=ene TEMPcompulsory keyword 
temperature =300 
   SELECTORcompulsory keyword 
name of the SELECTOR used for rescaling 
=GAMMA MAX_RESCALEcompulsory keyword 
maximum values for rescaling 
=1.2 NBINcompulsory keyword 
number of bins for gamma grid =2 
   W0 could not find this keyword 
=1000 BIASFACTORcompulsory keyword 
bias factor 
=100.0 BSTRIDEcompulsory keyword 
stride for writing bias 
=2000 BFILEcompulsory keyword 
file name for bias =bias.dat 
...The RESCALE action with label res calculates the following quantities:

 Quantity    Description  
res.bias the instantaneous value of the bias potential
res.igamma gamma parameter
res.accgamma MC acceptance for gamma
res.wtbias well-tempered bias


PRINT FILEthe name of the file on which to output these quantities 
=COLVAR ARGcompulsory keyword 
the labels of the values that you would like to print to the file 
=* STRIDEcompulsory keyword ( default=1 )
the frequency with which the quantities of interest should be output 
=100 The PRINT action with label

Glossary of keywords and components

Compulsory keywords

NAME	name of the SELECTOR
VALUE	set (initial) value of the SELECTOR

Quantity	Description
res.bias	the instantaneous value of the bias potential
res.igamma	gamma parameter
res.accgamma	MC acceptance for gamma
res.wtbias	well-tempered bias