Electronic structure and quantum simulation of materials

Basic course given by Stefano Baroni

Term: 1

Start: 07-10-2019 End: 16-12-2019 Room: 131

Credits: 6

Schedule: Mon 11:00 - 13:30, Tue 11:00 - 13:30

Program

The program below refers to the course held by S. de Gironcoli in 2018-2019. The new program will be uploaded soon.

The basic course will present fundamental concepts in the first-principles simulation of real materials at the nanoscale. Density Functional Theory will be introduced in its conceptual foundations and practical details of numerical atomistic simulations will be discussed. Strengths and shortcomings will be demonstrated in a number of case studies. Critical issues and open challenges will be introduced.

Evaluation will be based on course participation and performance in the two given assignments (one simpler and one more demanding).

 

1/10

Where all begins: adiabatic approximation. (slides)

4/10

Electrons moving in an effective potential.(slides)

8/10

Variational principle for the electronic problem. The Hartree-Fock self-consistent equations.(slides)

11/10

Hund's rules. Koopmans' theorems. Building up the periodic table. (slides)

15/10

Examples (Examples_1, slides) Homogeneous electron gas. Band magnetism. Wigner Crystal.(slides)

18/10

Density-Functional Theory. HK theorem, the KS equations. Jacob's ladder of xc functionals. (slides)

22/10

The standard model of DFT: LDA, GGA. Successes and problematic cases (slides)

24/10

.. continued (slides)

29/10

Band gap ''problem'' in DFT. The GW approximation.(slides)

5/11

Electronic structure of solids: Bloch theorem, basis set expansions, spectral methods (FFT), k-point sampling, pseudopotentials and the like. (slides) Examples (Examples_2)

8/11

 .. continued (slides)

12/11

Don't panic .... introduction to QE (slides,JPCM_2009,JPCM-2017

First assignment (text)

15/11

An almost free lunch: Hellmann-Feynman and Stress theorems. Structural optimization. Molecular Dynamics. Parrinello-Raman and Wentzcovitch dynamics. (slides) Car-Parrinello method. (slides) Examples (PW/examples/example02-example03-VCSexample; CPV/examples/example01-example02-example03)

19/11

Ab initio thermodynamics, catalysis,... (slides)

Crystal Structure Prediction from first principles, (slides)... and second principles

22/11

One step beyond: Density-Functional Perturbation Theory, general formulation.  (slides ,RMP-73-515-2001)

26/11

Dielectric properties, effective charges. Piezoelectric constants.(slides) Examples

29/11

Phonons, temperature, quasi-harmonic approximation and its relevance for 'real life'. (Beryllium , core_levels )

 

3/12

Wannier functions.(slides)

Berry Phases and macroscopic polarization. Electric Fields, effective charges etc revisited. (slides ,slides )

6/12

DFT: I would rather be approximately right than exactly wrong (SIC, DFT+U and other 'advanced' functionals)(slides). Examples

10/12

DFT: when everything else fails read the manual (the van der Waals interaction and the Adiabatic-Connection Fluctuation-Dissipation approach). (slides) Examples

13/12

Quantum ESPRESSO con PANNA. ( slides )

17/12

DFT: do the right thing: more ACFD stuff. ( slides )

19/12

DFT: more functionals, Strictly Correlated Electrons, LIISA ( pdf ) --- ( Projects )