Alignment of 3D structures on Principal axis


I would like to align 3D structures of small molecules along their principal axes.  Is there a node to do this?  

If not, I would like to use a PCA on the 3D coordinates to get the rotation matrix to do the coordinate transformation.  Is there an easy way to get the 3D coordinates into a property?

Also it would be nice to have a node that will apply a rotation/translation matrix to 3D structures.



I have just added an Align to Inertial Principal Axes node to the nightly build of the Vernalis nodes.  The plugin uses the RDKit toolkit.