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Přehled pracovišť:

Matematicko-fyzikální fakulta UK – Katedra chemické fyziky a optiky, Oddělení kvantové fyziky

Towards accurate methods for the description of molecular solids

Molecular solids are materials important both in the nature and in industries. Many methods are currently used to calculate the properties of molecular solid, such as their binding energies or the transition pressures between different phases. However, molecular solids are too large to be treated by highly accurate quantum chemistry methods and we need to introduce approximations to be able to compute their properties. Unfortunately, the approximations can be very severe and we often find a disagreement between the simulation and experiment. We have currently very little understanding of what are the causes of such disagreements. The PhD will develop ways to understand why many currently widely used methods, such as density functional theory functionals, fail and why they sometimes work. This will allow us to identify which methods and when can be trusted and which methods should be rather abandoned.

The position is fully funded by ERC and offers a competitive stipend. Please contact Dr. Jiri Klimes (klimes (at) karlov.mff.cuni.cz) or see http://quantum.karlov.mff.cuni.cz/~jklimes/ for more information.

Precision of ab-initio calculations

One of the main properties of interest of molecular solids is their binding energy. When we develop a new computational scheme for its calculation, we often compare if it gives better or worse results than the methods produced by competing groups. Clearly, such comparison only makes sense if the data for each method are precise, that is, converged with all the numerical parameters. Unfortunately, this is not what we often find. In the literature, there are significant differences between results obtained for identical methods. And the differences can be large, in fact, terribly large. They can be even found for results published with the same computational package! One of the goals of this project is to understand the limits of precision of widely used programmes and identify settings that allow trustworthy results to be obtained. This will allow the candidate to make reliable predictions of important properties of molecular solids, such as of the transition pressures between high pressure phases of matter.

The position is fully funded by ERC and offers a competitive stipend. Please contact Dr. Jiri Klimes (klimes (at) karlov.mff.cuni.cz) or see http://quantum.karlov.mff.cuni.cz/~jklimes/ for more information.