DFTB+, the Fast Way of Quantum Mechanical Simulations

TH Department Online Seminar
Date: Sep 22, 2022
Time: 02:00 PM (Local Time Germany)
Speaker: Dr. Bálint Aradi
BCCMS, CMS Research Group, Universität Bremen, Germany
Location: https://zoom.us/j/98402217373?pwd=ZnNLSi96UmxiVVlqK2pRaUV3anFPQT09
Room: Meeting ID: 984 0221 7373 | Passcode: 605622
Host: TH Department

The Density Functional Tight Binding (DFTB) method [1] is an approximate Density Functional Theory (DFT) based framework, which allows for quantum mechanicalsimulations of large systems being typically two or three orders of magnitudefaster than comparable ab initio DFT calculations.

Being derived with well defined approximations from ab initio DFT, it also provides a consistent way for porting DFT extensions into this approximative framework. Several of such extensions (e.g. hybrid functionals, time-dependent DFT in energy and time domain, Greens-function based electron transport, etc.) had been already successfully ported, and implemented among others in the DFTB+ code [2]. The code also implements the newly developed xTB method, which can be a flexible alternative to DFTB in certain use cases. In my presentation, I will sketch the basic ideas behind the DFTB and xTB formalisms, give an overview over some recently developed capabilities in the DFTB+ code and report about recent efforts to combine DFTB/xTB with machine learning approaches for materials simulations.

[1] M. Elstner, and G. Seifert, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, 20120483 (2014).

[2] B. Hourahine, B. Aradi et al., The Journal of Chemical Physics 152, 124101 (2020) .