Question: How can a computer tell you how a material behaves?

Harry Keen answered on 2 Jul 2020:

By giving the computer some very tough calculations to do!
Materials are made up of atoms, and atoms are made of a nucleus and some electrons. How the atoms arrange themselves, and how the electrons within them are arranged, gives birth to the wide variety of behaviour we see in all of the materials around us. How they are arranged can tell us whether a material will be strong or weak, whether it will be a metal or insulator, a magnet or non-magnetic. Carbon is a great example; depending on how the atoms are arranged it can be graphite, graphene, diamond and many other wacky things. All of which have drastically different properties!

The problem comes in figuring out how the electrons and nuclei arrange themselves. This is a really hard question to answer! But we know that they obey some complicated equations: these are the equations of quantum mechanics. It’s impossible for humans to solve these by hand, but with some clever trickery and very big computers, we can just about get some answers. This can help us predict new materials, or understand some of the weird results that our expermental colleagues see 🙂