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

Calculate multiple quaternions

See QUATERNION for more details

Examples

Glossary of keywords and components

Description of components

By default the value of the calculated quantity can be referenced elsewhere in the input file by using the label of the action. Alternatively this Action can be used to calculate the following quantities by employing the keywords listed below. These quantities can be referenced elsewhere in the input by using this Action's label followed by a dot and the name of the quantity required from the list below.

Quantity	Description
w	the real component of quaternion
i	the i component of the quaternion
j	the j component of the quaternion
k	the k component of the quaternion

The atoms involved can be specified using

ATOMS

the three atom that we are using to calculate the quaternion. For more information on how to specify lists of atoms see Groups and Virtual Atoms

Options

NUMERICAL_DERIVATIVES

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

NOPBC

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