Lecturer: Prof. Emilio Artacho
Fundamentals and main approximations of DFT ( Density Functional Theory Calculations)-based electronic structure; students should leave the course knowing:
- how to run DFT calculations from a pre-existing programme;
- how to converge the results with respect to technical parameters;
- the capabilities and limitations of the methods, addressing the different approximations separately.
Practicals will be based on SIESTA, ONETEP, and CASTEP.
Lectures:
- Many particle problem. Born Oppenheimer, Independent particles; Practical: Time for Mini-project coming from foundation course (see below). For students not doing the foundation course, exercise: 1D tight-binding ionic chain.
- Indistinguishable particles, Spin, Pauli, Aufbau; Practical: Continue as in 1.
- Hartree, SCF, double counting, Hartree-Fock, exchange, correlation; Practical: Band structure of diamond. Visualise: tools and graphics.
- Correlation: CI & QC direction. Complexity exponential wall (Kohn RMP & Phys Today). Practical: Siesta: k-point sampling; Converging & DOS: Diamond, Al.
- DFT: Intro; definition of density; local potential; Hohenberg-Kohn and Levy construction (Jones-Gunnarson). Practical: Siesta E(V) Diamond and Al. P(V). Murnaghan.
- Kohn-Sham. LDA, Ceperly Alder; GGAs. Bands. Band-gap problem. Practical: Siesta E(V) Diamond and Al: compare LDA, PBE, WC
- Forces, stress. -> MD & Relaxations. Hellman-Feynman. Variable cell; Practical: Siesta: relax H2O molecule & cell for MgSiO3 under strain (Ferro)?
- Pseudos; atom: generate C pseudo Practical: Generate Pseudo. Test it within atom and in bulk
- Bases; generate basis and plot. Practical: Generate basis. Test in bulk
- PBC: cells & supercells. Practical calculations. Accuracies, limits (highly correlated, dispersion interactions);
Practical: Start Mini-Project
The course can be complemented by (e.g. one lecture each)
- Quantum Monte Carlo
- Plane waves
- Excitations
- Transport
- Molecular dynamics