OBABEL(1) General Commands Manual (urm) OBABEL(1)
NAME
obabel - a converter for chemistry and molecular modeling data files
SYNOPSIS
obabel -Hhelp-options
obabel [OPTIONS] [-iinput-type | -:SMILES-string] infile [-ooutput-type]
-Ooutfile
DESCRIPTION
obabel is a cross-platform program designed to interconvert between many
file formats used in molecular modeling and computational chemistry and
related areas.
Open Babel is also a complete programmers toolkit for developing
chemistry software. For more information, see the Open Babel web pages
.
OPTIONS
If only input and output files are given, Open Babel will guess the file
type from the filename extension.
-:SMILES-string
Enter SMILES string and use it in place of an input file. The
SMILES-string might need to be enclosed in quotation marks to avoid
shell interpretation. More than one can be used, and a molecule
title can be included if enclosed in quotes.
-aoptions
Format-specific input options. See -Hformat-ID for options allowed
by a particular format
--addtotitle
Append text to the current molecule title
--addformula
Append the molecular formula after the current molecule title
-b Convert dative bonds: e.g., [N+]([O-])=O to N(=O)=O
-c Center atomic coordinates at (0,0,0)
-C Combine molecules in first file with others having the same name
-e Continue after errors
-d Delete Hydrogens
---errorlevel n
Filter the level of errors and warnings displayed:
1 = critical errors only
2 = include warnings too (default)
3 = include informational messages too
4 = include "audit log" messages of changes to data
5 = include debugging messages too
-f # For multiple entry input, start import with molecule # as the first
entry
-F Output the available fingerprint types
-h Add hydrogens
-H Output usage information
-Hformat-ID
Output formatting information and options for format specified
-Hall
Output formatting information and options for all formats
-iformat-ID
Specifies input format, see below for the available formats
-j, --join
Join all input molecules into a single output molecule entry
-k Translate computational chemistry modeling keywords (e.g., GAMESS
and Gaussian)
-m Produce multiple output files, to allow:
- Splitting one input file -- put each molecule into
consecutively numbered output files
- Batch conversion -- convert each of multiple input files
into a specified output format
-l # For multiple entry input, stop import with molecule # as the last
entry
-oformat-ID
Specifies output format, see below for the available formats
-Ooutfile
Specify the output file
-p Add Hydrogens appropriate for pH (use transforms in phmodel.txt)
--property
Add or replace a property (e.g., in an MDL SD file)
-s SMARTS
Convert only molecules matching the SMARTS pattern specified
--separate
Separate disconnected fragments into individual molecular records
-t All input files describe a single molecule
--title title
Add or replace molecular title
-xoptions
Format-specific output options. See -H format-ID for options
allowed by a particular format
-v SMARTS
Convert only molecules NOT matching SMARTS pattern specified
-V Output version number and exit
-z Compress the output with gzip
FILE FORMATS
The following formats are currently supported by Open Babel:
abinit -- ABINIT Output Format [Read-only]
acesin -- ACES input format [Write-only]
acesout -- ACES output format [Read-only]
acr -- ACR format [Read-only]
adf -- ADF cartesian input format [Write-only]
adfband -- ADF Band output format [Read-only]
adfdftb -- ADF DFTB output format [Read-only]
adfout -- ADF output format [Read-only]
alc -- Alchemy format
aoforce -- Turbomole AOFORCE output format [Read-only]
arc -- Accelrys/MSI Biosym/Insight II CAR format [Read-only]
ascii -- ASCII format [Write-only]
axsf -- XCrySDen Structure Format [Read-only]
bgf -- MSI BGF format
box -- Dock 3.5 Box format
bs -- Ball and Stick format
c09out -- Crystal 09 output format [Read-only]
c3d1 -- Chem3D Cartesian 1 format
c3d2 -- Chem3D Cartesian 2 format
cac -- CAChe MolStruct format [Write-only]
caccrt -- Cacao Cartesian format
cache -- CAChe MolStruct format [Write-only]
cacint -- Cacao Internal format [Write-only]
can -- Canonical SMILES format
car -- Accelrys/MSI Biosym/Insight II CAR format [Read-only]
castep -- CASTEP format [Read-only]
ccc -- CCC format [Read-only]
cdjson -- ChemDoodle JSON
cdx -- ChemDraw binary format [Read-only]
cdxml -- ChemDraw CDXML format
cht -- Chemtool format [Write-only]
cif -- Crystallographic Information File
cjson -- Chemical JSON
ck -- ChemKin format
cml -- Chemical Markup Language
cmlr -- CML Reaction format
cof -- Culgi object file format
com -- Gaussian Input [Write-only]
confabreport -- Confab report format [Write-only]
CONFIG -- DL-POLY CONFIG
CONTCAR -- VASP format
CONTFF -- MDFF format
copy -- Copy raw text [Write-only]
crk2d -- Chemical Resource Kit diagram(2D)
crk3d -- Chemical Resource Kit 3D format
csr -- Accelrys/MSI Quanta CSR format [Write-only]
cssr -- CSD CSSR format [Write-only]
ct -- ChemDraw Connection Table format
cub -- Gaussian cube format
cube -- Gaussian cube format
dallog -- DALTON output format [Read-only]
dalmol -- DALTON input format
dat -- Generic Output file format [Read-only]
dmol -- DMol3 coordinates format
dx -- OpenDX cube format for APBS
ent -- Protein Data Bank format
exyz -- Extended XYZ cartesian coordinates format
fa -- FASTA format
fasta -- FASTA format
fch -- Gaussian formatted checkpoint file format [Read-only]
fchk -- Gaussian formatted checkpoint file format [Read-only]
fck -- Gaussian formatted checkpoint file format [Read-only]
feat -- Feature format
fh -- Fenske-Hall Z-Matrix format [Write-only]
fhiaims -- FHIaims XYZ format
fix -- SMILES FIX format [Write-only]
fps -- FPS text fingerprint format (Dalke) [Write-only]
fpt -- Fingerprint format [Write-only]
fract -- Free Form Fractional format
fs -- Fastsearch format
fsa -- FASTA format
g03 -- Gaussian Output [Read-only]
g09 -- Gaussian Output [Read-only]
g16 -- Gaussian Output [Read-only]
g92 -- Gaussian Output [Read-only]
g94 -- Gaussian Output [Read-only]
g98 -- Gaussian Output [Read-only]
gal -- Gaussian Output [Read-only]
gam -- GAMESS Output [Read-only]
gamess -- GAMESS Output [Read-only]
gamin -- GAMESS Input
gamout -- GAMESS Output [Read-only]
gau -- Gaussian Input [Write-only]
gjc -- Gaussian Input [Write-only]
gjf -- Gaussian Input [Write-only]
got -- GULP format [Read-only]
gpr -- Ghemical format
gr96 -- GROMOS96 format [Write-only]
gro -- GRO format
gukin -- GAMESS-UK Input
gukout -- GAMESS-UK Output
gzmat -- Gaussian Z-Matrix Input
hin -- HyperChem HIN format
HISTORY -- DL-POLY HISTORY [Read-only]
inchi -- InChI format
inchikey -- InChIKey [Write-only]
inp -- GAMESS Input
ins -- ShelX format [Read-only]
jin -- Jaguar input format
jout -- Jaguar output format [Read-only]
k -- Compare molecules using InChI [Write-only]
lmpdat -- The LAMMPS data format [Write-only]
log -- Generic Output file format [Read-only]
lpmd -- LPMD format
mae -- Maestro format
maegz -- Maestro format
mcdl -- MCDL format
mcif -- Macromolecular Crystallographic Info
MDFF -- MDFF format
mdl -- MDL MOL format
ml2 -- Sybyl Mol2 format
mmcif -- Macromolecular Crystallographic Info
mmd -- MacroModel format
mmod -- MacroModel format
mna -- Multilevel Neighborhoods of Atoms (MNA) [Write-only]
mol -- MDL MOL format
mol2 -- Sybyl Mol2 format
mold -- Molden format
molden -- Molden format
molf -- Molden format
molreport -- Open Babel molecule report [Write-only]
moo -- MOPAC Output format [Read-only]
mop -- MOPAC Cartesian format
mopcrt -- MOPAC Cartesian format
mopin -- MOPAC Internal
mopout -- MOPAC Output format [Read-only]
mp -- Molpro input format [Write-only]
mpc -- MOPAC Cartesian format
mpd -- MolPrint2D format [Write-only]
mpo -- Molpro output format [Read-only]
mpqc -- MPQC output format [Read-only]
mpqcin -- MPQC simplified input format [Write-only]
mrv -- Chemical Markup Language
msi -- Accelrys/MSI Cerius II MSI format [Read-only]
msms -- M.F. Sanner's MSMS input format [Write-only]
nul -- Outputs nothing [Write-only]
nw -- NWChem input format [Write-only]
nwo -- NWChem output format [Read-only]
orca -- ORCA output format [Read-only]
orcainp -- ORCA input format [Write-only]
out -- Generic Output file format [Read-only]
outmol -- DMol3 coordinates format
output -- Generic Output file format [Read-only]
paint -- Painter format [Write-only]
pc -- PubChem format [Read-only]
pcjson -- PubChem JSON
pcm -- PCModel Format
pdb -- Protein Data Bank format
pdbqt -- AutoDock PDBQT format
png -- PNG 2D depiction
pointcloud -- Point cloud on VDW surface [Write-only]
pos -- POS cartesian coordinates format [Read-only]
POSCAR -- VASP format
POSFF -- MDFF format
pov -- POV-Ray input format [Write-only]
pqr -- PQR format
pqs -- Parallel Quantum Solutions format
prep -- Amber Prep format [Read-only]
pwscf -- PWscf format [Read-only]
qcin -- Q-Chem input format [Write-only]
qcout -- Q-Chem output format [Read-only]
report -- Open Babel report format [Write-only]
res -- ShelX format [Read-only]
rinchi -- RInChI [Write-only]
rsmi -- Reaction SMILES format
rxn -- MDL RXN format
sd -- MDL MOL format
sdf -- MDL MOL format
siesta -- SIESTA format [Read-only]
smi -- SMILES format
smiles -- SMILES format
smy -- SMILES format using Smiley parser [Read-only]
stl -- STL 3D-printing format [Write-only]
svg -- SVG 2D depiction [Write-only]
sy2 -- Sybyl Mol2 format
t41 -- ADF TAPE41 format [Read-only]
tdd -- Thermo format
text -- Read and write raw text
therm -- Thermo format
tmol -- TurboMole Coordinate format
txt -- Title format
txyz -- Tinker XYZ format
unixyz -- UniChem XYZ format
VASP -- VASP format
vmol -- ViewMol format
wln -- Wiswesser Line Notation [Read-only]
xed -- XED format [Write-only]
xml -- General XML format [Read-only]
xsf -- XCrySDen Structure Format [Read-only]
xyz -- XYZ cartesian coordinates format
yob -- YASARA.org YOB format
zin -- ZINDO input format [Write-only]
FORMAT OPTIONS
Individual file formats may have additional formatting options.
Input format options are preceded by -a, e.g., -as
Output format options are preceded by -x, e.g., -xn
For further specific information and options, use -Hformat-type, e.g.,
-Hcml
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
Standard conversion:
obabel ethanol.xyz -Oethanol.pdb
Conversion from a SMI file in STDIN to a Mol2 file written to STDOUT:
obabel -ismi -omol2
Split a multi-molecule file into new1.smi, new2.smi, etc.:
obabel infile.mol -Onew.smi -m
SEE ALSO
obenergy(1), obfit(1), obgrep(1), obminimize(1), obprop(1), obrotamer(1),
obrotate(1). The web pages for Open Babel can be found at:
AUTHORS
A cast of many, including the current maintainers Geoff Hutchison, Chris
Morley, Michael Banck, and innumerable others who have contributed fixes
and additions. For more contributors to Open Babel, see
COPYRIGHT
Copyright (C) 1998-2001 by OpenEye Scientific Software, Inc.
Some portions Copyright (C) 2001-2007 by Geoffrey R. Hutchison
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