MOPAC-GUI tutorial¶

This section contains tutorials that show you how to use MOPAC via the MOPAC-GUI. As the MOPAC-GUI is very similar to the ADF-GUI, we will focus here on MOPAC-specific features.

If you are not familiar with the ADF-GUI (or the MOPAC-GUI), please have a look at the Introduction and GUI Overview tutorials.

For example, it will show you how to start the MOPAC-GUI.

MOPAC (Molecular Orbital PACkage) is a semiempirical quantum chemistry program based on Dewar and Thiel’s NDDO approximation. It is available from OpenMOPAC. The documentation for MOPAC is also available on that site.

MOPAC is included with the ADF distribution. However, it needs to be enabled in your license file. If it is not enabled, please contact SCM to get more information. Note that MOPAC is free for academic users. The MOPAC that is included with the ADF distribution is the standard MOPAC from OpenMOPAC, with a minor modification to use the SCM license technique.

If you wish to use a MOPAC version different from the one included with the ADF distribution, you can do this by setting the SCM_MOPAC environment variable, either in your shell startup script or via the SCM → Preferences command:

• do not set SCM_MOPAC when you want to run the MOPAC included with the ADF package, in most situations this is the easiest solution
• set SCM_MOPAC to the complete path to the Mopac executable
• set SCM_MOPAC to some command if want to run MOPAC on a different machine, the command must pass the arguments and standard input, and should start the mopac.scm script on the other machine (located in $ADFHOME/bin)