Special Seminar - Dr. Eli Kraisler - 23/1/2023

The Department of Chemistry Special Seminar

Monday January 23th, 12 PM

Location: Chemistry hall 112

 

Steps in density functional theory (DFT) potentials: exact properties and advanced approximations

Dr. Eli Kraisler (HUJI)

 

Density functional theory (DFT) is the leading theoretical framework used to describe electronic structure of materials. The most common approach in DFT is that of Kohn and Sham: it describes a material, namely, a system of N interacting electrons, via a fictitious system of N non-inteacting electrons subject to an effective potential termed the Kohn-Sham (KS) potential. The KS potential – a central quantity DFT – is known to exhibit sharp, non-analytic properties, such as steps and plateaus, in various scenarios, such as dissociation, ionization, excitation and charge transfer. However, these properties are rarely modelled in common approximations.

In this talk I discuss the step structure of the KS potential, highlight the common origin of steps that appear in different situations and underscore the significance of steps, serving the bridge between the real, many-electron energy differences and the fictitious Kohn-Sham energies. I further show that the Pauli potential – a central quantity in orbital-free DFT (OF-DFT) and in the emerging exact electron factorization (EEF) method – exhibits steps, as well. Surprisingly, detailed analytic characterization of the Pauli steps opens the door to accurately approximate also the KS potential. I suggest ways to encorporate potential steps in new approximations to exchange and correlation in DFT.

Please add your names if you would like to meet with him. The schedule ends at 14:00 because of our departmental meeting. However, there are a few people cc'd here that are not from Chemistry, you are welcome to meet with him after 14:00 as well. 

 https://docs.google.com/spreadsheets/d/10YqpG3Dhj1innkjMww2CmUuRuxYEHdKk/edit?usp=share_link&ouid=105730525730877131414&rtpof=true&sd=true

Looking forward to seeing you!

Abstract (pdf)

Last Updated Date : 22/01/2023