The default interpretation of units for coordinates in
CML is probably wrong. CDK handles files without a unit
for coordinates as not set, while there is a default
Please see attached my correspondens with Henry Rzepa,
who is involved in the CML file format:
"CML can and should declare units, but in the case of
coordinates, the default is normally well behaved.
If CML declares 3D units, these DO default to angstroms.