MOPAC: fast semi-empirical

Fast MD, geometries, and frequencies. Solvation models.
Easy to set up & run with the excellent GUI.

See Application Areas
or Try the Amsterdam Modeling Suite!


Fast semi-empirical with integrated GUI

MOPAC could bring the quantum precision you need to study large molecules or periodic systems. A good trade-off between speed and accuracy is achieved through a minimal basis and parameterization against experimental data, with parameters available for most elements.

Like DFTB, the semi-empirical MOPAC code uses the nearest neighbor and minimal basis set approximations, making it fast and linear scaling. MOPAC has been parameterized against an enormous set of thoroughly examined experimental data, in a huge, commendable effort by Dr. Jimmy Stewart. The latest parameterization set (PM7) is also the most accurate. Since AMS2019, the MOPAC and DFTB modules are now bundled together and only one license is needed to use both methods.

To accelerate your research, use MOPAC for quick pre-optimization, prescreening of a large number of molecules or crystals, or to get results on really large molecules which are out of reach for DFT or ab initio methods.

Polymer builder in GUI

Access large systems or script workflows

With the integrated Graphical interface it is easy to run, set up and analyze MOPAC jobs, or use it as a pre-optimization tool.

You can fully unlock the strength of MOPAC through the integration to our powerful AMS driver for complex potential energy surface tasks and the PLAMS python scripting environment.

Exchanging data and results from MOPAC to other Engines of the Amsterdam Modeling Suite is easy. You can therefore for example easily extract a snapshot from a ReaxFF molecular dynamics run and examine its electronic properties with MOPAC. Likewise, MOPAC coordinates can be readily transferred to ADF for a more accurate DFT calculation on desired properties. Quickly set up your own workflows, such as taking snapshots from advanced MD runs, or quickly (pre)screening many candidate molecules or materials for specific properties.

With AMS you can also do complex potential energy surface scans, accelerated MD, Monte Carlo methods and many properties using MOPAC as an integrated library.

Try MOPAC in AMS yourself!