Confab - Systematic generation of diverse low-energy conformers NM O'Boyle, T Vandermeersch, CJ Flynn, AR Maguire, GR Hutchison. Journal of Cheminformatics 2011, 3:8.
The software itself is available from http://confab.googlecode.com.
Here's the abstract of the paper:
Many computational chemistry analyses require the generation of conformers, either on-the-fly, or in advance. We present Confab, an open source command-line application for the systematic generation of low-energy conformers according to a diversity criterion.
Confab generates conformations using the 'torsion driving approach' which involves iterating systematically through a set of allowed torsion angles for each rotatable bond. Energy is assessed using the MMFF94 forcefield. Diversity is measured using the heavy-atom root-mean-square deviation (RMSD) relative to conformers already stored. We investigated the recovery of crystal structures for a dataset of 1000 ligands from the Protein Data Bank with fewer than 1 million conformations. Confab can recover 97% of the molecules to within 1.5 A at a diversity level of 1.5 A and an energy cutoff of 50 kcal/mol.
Confab is available from http://confab.googlecode.com.