Atoms on common planes

SHELXL calculates a least-squares plane through the first na atoms of the named atoms. The equation of this plane, together with the deviations of all named atoms from the plane and the angle to the previous least-squares plane (if present) are written into the. 1st file. If na is not specified, the program fits the plane through all named atoms. 

This command can also be used to determine the distance of an atom from a plane. If the task is to calculate the distance of a metal atom (say Ti(l)) from a Cp ligand (say atoms C(l)-C(5)), which coordinates to the metal via aU five carbon atoms (typical rjS style binding of Cp), the MPLA command looks like this  

This calculates the best plane through the first five atoms (the Cp ligand) and the distance of all atoms mentioned (including the Ti) from that plane. All distances, together with standard uncertainties, are written into the. 1st file. 

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