<tr><tdwidth=10%><b> Symbol </b></td><td><b> Topology type </b></td><td><b> Despription </b></td></tr>
<tr><td>\@phi-\#</td><td> protein </td><td>
The torsional angle defined by the C, CA, N and C atoms of the protein backbone in the \#th residue. See http://en.wikipedia.org/wiki/Ramachandran_plot
</td></tr>
<tr><td>\@psi-\#</td><td> protein </td><td>
The torsional angle defined by the N, C, CA and N atoms of the protein backbone in the \#th residue. See http://en.wikipedia.org/wiki/Ramachandran_plot
</td></tr>
<tr><td>\@omega-\#</td><td> protein </td><td>
The torsional angle defined by the CA, N, C and CA atoms of the protein backbone in the \#th residue. See http://en.wikipedia.org/wiki/Ramachandran_plot
</td></tr>
<tr><td>\@chi1-\#</td><td> protein </td><td>
The first torsional angle of the sidechain of the \#th residue. Be aware that this angle is not defined for GLY or ALA residues.
See http://en.wikipedia.org/wiki/Ramachandran_plot
</td></tr>
</table>
The following example shows how to use \ref MOLINFO with \ref TORSION to calculate the torsion angles phi and psi for the first and fourth residue
of the protein:
\plumedfile
MOLINFO MOLTYPE=protein STRUCTURE=myprotein.pdb
t1: TORSION ATOMS=@phi-3
t2: TORSION ATOMS=@psi-4
PRINT ARG=t1,t2 FILE=colvar STRIDE=10
\endplumedfile
\subsection pbc Broken Molecules and PBC
PLUMED is designed so that for the majority of the CVs implemented the periodic boundary conditions are treated