Summer of V’s: Veracity through variety (of methods), by Tanja van Mourik

Tanja’s abstract and slides from the Summer of V’s event.

In my research I use computational quantum chemistry, which applies the principles of quantum mechanics to chemistry. One particular type of quantum-chemical methods, the “first principles” methods, result directly from the quantum-mechanical equations and therefore do not require empirical calibration. With these methods, virtually any molecular property can be calculated; however, the calculations are very computationally demanding. An additional problem is that determining the most favoured structure (“shape”) of a molecule consisting of ~30 atoms (like the molecule shown in the figure), requires calculating the optimal geometry and energy of around 125000 conformations, making this a challenging problem.

In this presentation I show the application of quantum chemistry to deduce the shape of a small peptide, which turns out to be a particularly challenging molecule. I will show that two of the most popular first principles methods do not give correct results for this particular system.

Slides (ppt)