Seminar in Numerical Analysis: Luca Frediani (University of Tromsø)

All-electron Density Functional Theory Calculations for atoms and molecules using Multiwavelets and Massively Parallel Architectures

Most modern molecular electronic structure calculations are based on Density Functional Theory (DFT) due to the very convenient balance between accuracy and required computational resources. The accuracy of the result is then dependent on the quality of the functional and the chosen basis set. By replacing traditional Gaussian Type Orbitals (GTOs) with Multiwavelets, the basis set can be made practically complete making the lack of the "exact" functional as the only source of error left. We have implemented a Multiwavelet-based DFT code, which makes use of the integral formulation of the Kohn-Sham equations of DFT. Different strategies to optimize the density have been attempted and will be presented. The main limitation of the present approach is the large memory demand of the software compared to traditional methods. In order to overcome such a limitation a massively parallel implementation has been developed for the kernel of the code: the application of the Green's operator represented in the so called Non-Standard form.

Veranstaltung übernehmen als iCal