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

Depreciated command that is bascially equivalant to GROUP.

Plase don't use this anymore

Examples
Glossary of keywords and components
Description of components
Quantity Description
.#!value indices for the specified group of atoms
Compulsory keywords
SPECIES the atoms in the group