This is part of the mapping module

Property maps but with a more flexible framework for the distance metric being used.

This colvar calculates a property map using the formalism developed by Spiwork [43]. In essence if you have the value of some property, \(X_i\), that it takes at a set of high-dimensional positions then you calculate the value of the property at some arbitrary point in the high-dimensional space using:

\[ X=\frac{\sum_i X_i*\exp(-\lambda D_i(x))}{\sum_i \exp(-\lambda D_i(x))} \]

Within PLUMED there are multiple ways to define the distance from a high-dimensional configuration, \(D_i\). You could calculate the RMSD distance or you could calculate the ammount by which a set of collective variables change. As such this implementation of the propertymap allows one to use all the different distance metric that are discussed in Distances from reference configurations. This is as opposed to the alternative implementation PROPERTYMAP which is a bit faster but which only allows one to use the RMSD distance.

Compulsory keywords

REFERENCE	a pdb file containing the set of reference configurations
PROPERTY	the property to be used in the index. This should be in the REMARK of the reference
TYPE	( default=OPTIMAL-FAST ) the manner in which distances are calculated. More information on the different metrics that are available in PLUMED can be found in the section of the manual on Distances from reference configurations
LAMBDA	the value of the lambda parameter for paths

Options

NUMERICAL_DERIVATIVES	( default=off ) calculate the derivatives for these quantities numerically
SERIAL	( default=off ) do the calculation in serial. Do not parallelize
LOWMEM	( default=off ) lower the memory requirements
TIMINGS	( default=off ) output information on the timings of the various parts of the calculation
DISABLE_CHECKS	( default=off ) disable checks on reference input structures.
NOZPATH	( default=off ) do not calculate the zpath position
NOMAPPING	( default=off ) do not calculate the position on the manifold

Examples