OBGEN(1)                 General Commands Manual (urm)                OBGEN(1)

NAME
     obgen - generate 3D coordinates for a molecule

SYNOPSIS
     obgen [OPTIONS] filename

DESCRIPTION
     The obgen tool will generate 3D coordinates for molecules in a file (e.g.
     multi-molecule SMILES files).  The resulting structure will be optimized
     using the given forcefield and checked for the lowest-energy conformer
     using a Monte Carlo search.  Output will be sent to standard output in
     the SDF file format.

OPTIONS
     If no filename is given, obgen will give all options including the
     available forcefields.

     -ff forcefield
           Select the forcefield

ENVIRONMENT
     OB_RANDOM_SEED
           Seed for pseudo random number generator; random seed is used if
           unset or null.  This feature is effective if Open Babel is built
           with -DOB_USE_OBRANDOMMT cpreprocessor flag (will be automatically
           enabled when version 4 is released).

EXAMPLES
     View the possible options, including available forcefields:
           obgen

     Generate 3D coordinates for the molecule(s) in file test.smi:
           obgen test.smi

     Generate 3D coordinates for the molecule(s) in file test.smi using the
     UFF forcefield:
           obgen -ff UFF test.smi

SEE ALSO
     obabel(1), obconformer(1), obminimize(1).

     The web pages for Open Babel can be found at: <https://openbabel.org/>

     The web pages for Open Babel Molecular Mechanics can be found at:
     <https://openbabel.org/docs/Forcefields/Overview.html>

AUTHORS
     The obgen program was contributed by Tim Vandermeersch.

     Open Babel is developed by a cast of many, including current maintainers
     Geoff Hutchison, Chris Morley, Michael Banck, and innumerable others who
     have contributed fixes and additions.  For more contributors to Open
     Babel, see <https://openbabel.org/docs/Introduction/thanks.html>

COPYRIGHT
     Copyright (C) 2007-2008 by Tim Vandermeersch.

     This program is free software; you can redistribute it and/or modify it
     under the terms of the GNU General Public License as published by the
     Free Software Foundation version 2 of the License.

     This program is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
     Public License for more details.

Open Babel 3.2                   May 26, 2026                   Open Babel 3.2