---
name: "obminimize"
section: "1"
platform: "linux"
package: "openbabel"
version: "3.2.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/obminimize"
---

# obminimize(1)

optimize the geometry, minimize the energy for a molecule

## NAME

**obminimize** – optimize the geometry, minimize the energy for a molecule

## SYNOPSIS

**obminimize** \[*OPTIONS*\] *filename*

## DESCRIPTION

The **obminimize** tool can be used to minimize the energy for molecules inside (multi-)molecule files (e.g., MOL2, etc.)

## OPTIONS

If no filename is given, **obminimize** will give all options including the available forcefields.

- **-c** *criteria*

  Set convergence criteria (default=1e-6)

- **-cg**

  Use conjugate gradients algorithm (default)

- **-sd**

  Use steepest descent algorithm

- **-newton**

  Use Newton2Num linesearch (default=Simple)

- **-ff** *forcefield*

  Select the forcefield

- **-o** *format*

  Select the output file format

- **-h**

  Add hydrogen atoms

- **-n** *steps*

  Specify the maximum number of steps (default=2500)

- **-cut**

  Use cut-off (default=don't use cut-off)

- **-rvdw** *rvdw*

  Specify the VDW cut-off distance (default=6.0)

- **-rele** *rele*

  Specify the Electrostatic cut-off distance (default=10.0)

- **-pf** *freq*

  Specify the frequency to update the non-bonded pairs (default=10)

## EXAMPLES

View the possible options, including available forcefields:

```
obminimize
```

Minimize the energy for the molecule(s) in file test.mol2:

```
obminimize test.mol2
```

Minimize the energy for the molecule(s) in file test.mol2 using the Ghemical forcefield:

```
obminimize -ff Ghemical test.mol2
```

Minimize the energy for the molecule(s) in file test.mol2 by taking at most 300 geometry optimization steps

```
obminimize -n 300 test.mol2
```

Minimize the energy for the molecule(s) in file test.mol2 using the steepest descent algorithm and convergence criteria 1e-5:

```
obminimize -sd -c 1e-5 test.mol2
```

## SEE ALSO

[obabel(1)](/obabel/1.md), [obenergy(1)](/obenergy/1.md), [obrotamer(1)](/obrotamer/1.md).

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 minimize 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 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.