Fast treatment of pi-stacking using Density Functional Theory.

[摘要] In this work, we concentrate on various unconventional DensityFunctional Theory approaches for calculations of electronicstructure of molecules. In particular, we are motivated by gainingsubstantial speed-up of such calculations. Firstly, explore theOrbital-Free Density Functional Theory and show how one cancompute the energies of dimers by performing large-scaleoptimization with more than a million variables. We also showthat this approach does not give satisfactory results. Secondly,we investigate tight-binding methods and in particular showthat Harris approximation gives good results when applied tocalculations of energies of dimers. In the last section, we applyHarris approximation to molecular packing optimization,and show thatthe SPSA algorithm is capable of finding all minima of the energy surface.

[发布机构] the University of Pittsburgh