Open course ware

NICOLA MARZARI: Welcome, everyone. Lecture 8-- hopefully this will be a somehow simpler class to follow than last class. That was sort of heavily theoretical. What we are going to do today is really, after two or three slides of recap of what we have seen in the past lecture, we'll go into really sort of practical application of density functional theory. We'll first discuss how you set up calculations. That is, what are the parameters, and what are the objects that you manipulate when you do an electron [INAUDIBLE] calculation? And then we start seeing a number of examples to give you the feeling for the properties that we can calculate using density function theory for the accuracy and for the pitfalls you need to be careful with. And in the next class on Thursday, we'll finish up with more case studies. So let me actually spend three slides to recap what we have seen in the last lecture. Starting somehow from this, that, I would say, is the most fundamental...

NICOLA MARZARI: --for all our applications and for the lab sessions. I guess I keep using Albert Einstein. This is the 100th anniversary of his sort of famous year, 1905, so just a little celebration. One slide of a reminder of what we have seen in the previous lecture, we have really developed the formalism leading to the Hartree-Fock equations. And the Hartree-Fock equation follow from a set of very simple and very beautiful path. We have the Schrodinger equation, and we have reformulated the Schrodinger equation in terms of the variational principle. So we have a functional. And we know that we can throw into that functional any arbitrary wave function, and it'll give us an expectation value of the energy. And sort of the closer we get to the true ground state wave function, the lower that energy is going to be. We are never going to go below the ground state energy. And so it's sort of a very powerful approach to try out sorts of possibilities and solution. An...