A SEAMM plug-in for simple, quick minimization

• Free software: BSD-3-Clause
• Documentation: https://molssi-seamm.github.io/quickmin_step/index.html
• Code: https://github.com/molssi-seamm/quickmin_step

QuickMin provides quick, simple optimization of molecular structures using one of a number of forcefields. It is intended for small systems, with no more than about 300 atoms. Beyond that size it will be rather slow, but more importantly larger systems typically have many local minima, often close to each other energetically, so the concept of the minimum structure is not very useful.

QuickMin uses OpenBabel for the minimization. There are currently five forcefields available:

1. GAFF -- the general AMBER force field
2. MMFF94 -- the Merck molecular force field
3. MMFF94s -- the Merck molecular force field for energy minimization
4. Ghemical
5. UFF -- Universal force field

The first four have parameters for organic and biomolecular systems, while UFF attempts to cover the entire periodic table with reasonable accuracy. The more specialized forcefields tend to be more accurate, roughly in the order listed (though the two MMFF94 are essentially similar). By default QuickMin will try each of the forcefields in the order given until it finds one that can handle the given molecule. You can specify the forcefield to use; however, if it does not have parameters for your molecule, QuickMin will throw an error.

This package was created with the molssi-seamm/cookiecutter-seamm-plugin tool, which is based on the excellent Cookiecutter.

Developed by the Molecular Sciences Software Institute (MolSSI), which receives funding from the National Science Foundation under award CHE-2136142.