Updated docstring and README.md

README.md

@@ -46,6 +46,7 @@ The CVs implemented in CVPack are listed in the table below.
 | [Helix RMSD content]    | alpha-helix RMSD content of a sequence of residues               |
 | [Helix torsion content] | alpha-helix Ramachandran content of a sequence of residues       |
 | [Number of contacts]    | number of contacts between two groups of atoms                   |
+| [OpenMM Force wrapper]  | converts an OpenMM Force object into a CVPack CV                 |
 | [PathInCVSpace]         | progress along (deviation from) a predefined path in CV space    |
 | [Radius of gyration]    | radius of gyration of a group of atoms                           |
 | [(Radius of gyration)^2]| square of the radius of gyration of a group of atoms             |

cvpack/openmm_force_wrapper.py

@@ -18,7 +18,8 @@
 
 class OpenMMForceWrapper(BaseCollectiveVariable):
     r"""
-    A generic collective variable.
+    A collective variable whose numerical value is computed from the potential energy,
+    in kJ/mol, of an OpenMM force object.
 
     Parameters
     ----------