The Hartree-Fock method

Introduction Last time we ended up with a simplified Hamiltonian: and having the variational principle for help. It turns out that this simplified Hamiltonian is not simple enough. In this post I’ll expose one method that allows one to do calculations for quite complex quantum systems, the Hartree-Fock method. Because the subject is quite large, … Read more

How to solve a quantum many body problem

Introduction Quite a bit of time passed since my last post on this blog. I had a visit to the sunny Spain, I switched to a double-surface hang glider and I had to take a little care of my firm. Despite those things, I did a little bit of work for the blog, but it … Read more

Event Driven Molecular Dynamics

Event Driven Molecular Dynamics

Introduction I intended to have some molecular dynamics code for this blog, something a little bit more complex than the one described at Newtonian Gravity post, perhaps something with neighbors lists or maybe again something about gravity but with a Barnes–Hut simulation. I’ll do that maybe later. I found that there are plenty of places … Read more

Magnetization for 2D Ising Model

Metropolis for 2D Ising and spin block renormalization

Introduction After quite a bit of time, here is the C++ program I promised. I’ve made a youtube video just to present it, for more meaningful results it must run with way more sweeps than in the video: It turned out that the program I used for making the video had some troubles with the … Read more