obrms — Calculate the heavy-atom RMSD between two chemically identical structures

       Open Babel is developed by a cast of many, including currrent maintainers Geoff Hutchison, Chris  Morley,
       Michael Banck, and innumerable others who have contributed fixes and additions.  For more contributors to
       Open Babel, see <http://openbabel.org/wiki/THANKS>

       Copyright (C) 1998-2001 by OpenEye Scientific Software, Inc.
       Some portions Copyright (C) 2001-2007 by Geoffrey R. Hutchison and other contributors.

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       General Public License as published by the Free Software Foundation version 2 of the License.

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Open Babel 3.1                                    Oct 10, 2019                                          obrms(1)

       Computes  the  heavy-atom RMSD of identical compound structures.  Structures in multi-structure files are
       compared one-by-one unless -firstonly is passed, in which case only the first structure in the  reference
       file is used.

obrmsref.sdftest.sdf

       Calculate the RMSD between ref.sdf and test.sdf.  Both files should have the same number of molecules.

             obrms-fref.sdftest.sdf

       Calculate the RMSD between the first molecule in ref.sdf and each molecule in test.sdf.

       obrms — Calculate the heavy-atom RMSD between two chemically identical structures

-f,--firstonly
             use  only  the  first  structure in the reference file (otherwise the nth molecule in the reference
             file is compared to the nth molecule in the test file)

       -m,--minimize
             Compute the minimum RMSD achievable by applying a rigid-body transformation to the test molecule

       -x,--cross
             Compute all n^2 RMSDs between molecules of the reference file.  Test file is ignored.

       -s,--separate
             Separate reference file into constituent molecules (disconnected fragments) and report best RMSD

       -o,--out
             Re-oriented test structure output (used with -m)

obfit(1).

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obrms [-fmxso] filename1filename2