This is part of the multicolvar module

Calculate all the angles between bonds in the first coordination spheres of a set of atoms

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
between	BETWEEN	the number of colvars that have a value that lies in a particular interval
sum	SUM	the sum of the colvars
mean	MEAN	the mean of the colvars

CATOMS	all the angles between the bonds that radiate out from these central atom are computed. For more information on how to specify lists of atoms see Groups and Virtual Atoms
GROUP	a list of angls between pairs of bonds connecting one of the atoms specified using the CATOM command and two of the atoms specified here are computed. For more information on how to specify lists of atoms see Groups and Virtual Atoms

SWITCH

the switching function specifies that only those bonds that have a length that is less than a certain threshold are considered

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