Regensburg 2025 – scientific programme

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DS: Fachverband Dünne Schichten

DS 13: Poster

DS 13.2: Poster

Thursday, March 20, 2025, 18:00–20:00, P1

Wannier description using CP2K — •Nisarg Trivedi, Maximilian F. X. Dorfner, and Frank Ortmann — School of Natural Sciences, Technische Universität München

Wannier functions provide an ideal basis for simulating quantum transport using Model Hamiltonians (i.e., tight binding models). Most Wannier generation tools use a plane-wave basis to expand the Wannier functions. However, using a gaussian basis to expand such functions can make simulations more efficient by using the sparsity of the matrices. Here, we present a procedure to obtain moderately localized Wannier functions on an atom-centered gaussian basis. Interfaced with the CP2K software, the method uses the Kohn-Sham Hamiltonian and Overlap matrices obtained from DFT simulation in the same atom-centered gaussian basis to obtain the Bloch states and then transform them into Wannier functions. We present the results of the application of this method on different polymers, which show excellent reproduction of band structure using a simple tight binding model based on the respective Wannier functions for all studied polymers.

Keywords: Organic Semiconductors; Transport simulations; Wannier functions; Gaussian basis