IQmol logo


News - 1 July 2011

The first stable release for OS X. This is a largely rewritten version that incorporates stability enhancements and more intuitive support for viewing multiple molecules. Multiple levels of undo have also been added.

Overview of Features

IQmol is a simple molecular viewer/builder written using the Qt libraries. It currently has the following capabilities:

  • Read and write a variety of molecular formats thanks to the OpenBabel library.
  • Free-form building including molecular mechanics minimization of structures.
  • Four model views including CPK, VDW, tubes and wireframe.
  • SymMol integration allows nearby structures with higher symmetry to be found.
  • Visualization of molecular orbitals and densities.
  • Fast surface generation for multiple molecular orbitals.
  • Visualization and animation of normal mode vibrations.
  • Visualization and animation of optmization and IRC pathways (requres QChem output file).
  • Hierarchical Model View shows data structures in an intuitive way.


Currently IQmol is at the beta stage of development. Before installing IQmol you will need to ensure you have the latest version of OpenBabel 2.3.0. installed.

If you wish to run the QChem input file extension you will need ensure you have installed QChem and have the $QC/bin/qchemrun script installed. For OS X and Linux the script contains the following:

   #! /bin/csh
   source ~/.cshrc
   qchem $1

For Windows it's anyone's guess. Make sure the qchemrun script is executable (chmod +x qchemrun) and that the path to this has been set in the IQmol Preferences.

Screen Shots

Known Problems

IQmol relies on the Qt SQLite plugin to interface with a datbase file. It appears that under OS X, the database file is locked if IQmol is launched off a networked file system. If this is the case the program may crash when accessing the Calculation→Ssetup menu. Currently the only work-around for this is to ensure the bundle is stored on a local volume.