Dear colleagues,

 

The next ETSF seminar will be given by Ayoub Aouina from the Ecole Polytechnique in Palaiseau, France, on Friday April 1 at 14:00 CEST. 

The title of the talk is “New approximation to the exchange correlation potential from connector theory approach”. 

Below you will find an abstract of the seminar.

 

All ETSF members will receive an email with a zoom link a couple of days before the seminar

If you are not an ETSF member and you would like to follow the seminar please send an email to [email protected].

In the Kohn-Sham formulation of density functional theory (DFT) [1], the ground-state density of interacting electrons can be obtained from a fictitious system of independent particles in an effective potential. Although DFT is in principle exact the effective potential contains an unknown quantity called the exchange-correlation (xc) potential. In this talk we propose a new approximation to the xc potential using a general approach called "Connector Theory" (COT) [2]. This approach is a prescription of how to use data from models to calculate quantities in materials. COT is in principle exact but in practice approximations are needed to make it useful. After introducing the general scheme of this approach, we will explain how to use our approximate xc potential in the self-consistent Kohn-Sham loop to calculate the electronic density. By comparing the resulting density of silicon with benchmark Quantum Monte Carlo results [3], we find a very good agreement. Finally, we will examine the inverse question of obtaining the xc potential from the accurate QMC density. Our aim from this inversion is to analyse the features of the exact xc potential and to compare it with the COT and other DFT approximations.

 

[1] P. Hohenberg and W. Kohn, Phys. Rev. 136, B864 (1964).

 

[2] M. Vanzini, A. Aouina, M. Panholzer, M. Gatti, and L. Reining, accepted, npj Computational Materials (2022).

 

[3] S. Chen, M. Motta, F. Ma and S. Zhang, Phys. Rev. B 103, 075138 (2021).