- Automatic conformer selection by relevance to the chemical potential (μ-clustering) in diverse solvents
- Good accuracy and robustness due to use of density functional theory calculations
- Large molecules, more than 100 atoms are feasible
- User-defined conformational search schemes for full flexibility
- Command line version available for automated batch processing
Conformers are stereoisomers which can be interconverted by rotations about formally single bonds. Each conformer can have a different energy, polarity and hydrogen bonding capacity. Because these properties are essential for the interactions and therefore the basis for COSMO-RS predictions, the correct conformational average should be used to achieve optimal prediction accuracy. Using only a single conformation can cause significant errors. BIOVIA COSMOtherm calculates the relative Boltzmann statistics in the mixture under consideration and automatically uses the conformer ensemble.
The aspirin example in the table above shows the influence of the solvent on the population of the conformers. The conformation with hydrogen bond (c2) has nearly no importance in water, but cannot be neglected in hexane.
Due to the complexity of the problem there is no simple method which works for every purpose. BIOVIA COSMOconf offers automated procedures, which will give good results on average. Still it is a heuristic method and thus might miss relevant conformations by chance.
