SMAC
This is part of the symfunc module
It is only available if you configure PLUMED with ./configure –enable-modules=symfunc . Furthermore, this feature is still being developed so take care when using it and report any problems on the mailing list.

Calculate the SMAC order parameter for a set of molecules

Examples
Glossary of keywords and components
Description of components
Quantity Description
.#!value the value of the smac parameter for each of the input molecules

In addition the following quantities can be calculated by employing the keywords listed below

Quantity Keyword Description
lessthan LESS_THAN the number of colvars that have a value less than a threshold
morethan MORE_THAN the number of colvars that have a value more than a threshold
altmin ALT_MIN the minimum value of the cv
min MIN the minimum colvar
max MAX the maximum colvar
between BETWEEN the number of colvars that have a value that lies in a particular interval
highest HIGHEST the largest of the colvars
lowest LOWEST the smallest of the colvars
sum SUM the sum of the colvars
mean MEAN the mean of the colvars
Options
HIGHEST ( default=off ) this flag allows you to recover the highest of these variables.
LOWEST ( default=off ) this flag allows you to recover the lowest of these variables.
SUM ( default=off ) calculate the sum of all the quantities.
MEAN

( default=off ) calculate the mean of all the quantities.

SPECIES
SPECIESA
SPECIESB
SWITCH This keyword is used if you want to employ an alternative to the continuous swiching function defined above. The following provides information on the switchingfunction that are available. When this keyword is present you no longer need the NN, MM, D_0 and R_0 keywords.
KERNEL The kernels used in the function of the angle. You can use multiple instances of this keyword i.e. KERNEL1, KERNEL2, KERNEL3...
SWITCH_COORD This keyword is used to define the coordination switching function.
LESS_THAN calculate the number of variables that are less than a certain target value. This quantity is calculated using \(\sum_i \sigma(s_i)\), where \(\sigma(s)\) is a switchingfunction.. You can use multiple instances of this keyword i.e. LESS_THAN1, LESS_THAN2, LESS_THAN3...
MORE_THAN calculate the number of variables that are more than a certain target value. This quantity is calculated using \(\sum_i 1 - \sigma(s_i)\), where \(\sigma(s)\) is a switchingfunction.. You can use multiple instances of this keyword i.e. MORE_THAN1, MORE_THAN2, MORE_THAN3...
ALT_MIN calculate the minimum value. To make this quantity continuous the minimum is calculated using \( \textrm{min} = -\frac{1}{\beta} \log \sum_i \exp\left( -\beta s_i \right) \) The value of \(\beta\) in this function is specified using (BETA= \(\beta\)).
MIN calculate the minimum value. To make this quantity continuous the minimum is calculated using \( \textrm{min} = \frac{\beta}{ \log \sum_i \exp\left( \frac{\beta}{s_i} \right) } \) The value of \(\beta\) in this function is specified using (BETA= \(\beta\))
MAX calculate the maximum value. To make this quantity continuous the maximum is calculated using \( \textrm{max} = \beta \log \sum_i \exp\left( \frac{s_i}{\beta}\right) \) The value of \(\beta\) in this function is specified using (BETA= \(\beta\))
BETWEEN calculate the number of values that are within a certain range. These quantities are calculated using kernel density estimation as described on histogrambead.. You can use multiple instances of this keyword i.e. BETWEEN1, BETWEEN2, BETWEEN3...
HISTOGRAM calculate a discretized histogram of the distribution of values. This shortcut allows you to calculates NBIN quantites like BETWEEN.