Tight binding

Tight binding is when tiny things called atoms stick together by sharing their electrons. Think of atoms like tiny little balls, and electrons are like even tinier little balls that move around the outside of the atoms.

When two atoms get close enough to each other, their electrons start to interact and share space. This means that some of the electrons from one atom start to spend some of their time around the other atom, and vice versa.

The electrons from each atom form little "bonds" with the other atom's electrons, which holds the two atoms together. These bonds are like little hooks or magnets that keep the atoms stuck to each other, even though they're both still separate things.

If you have a lot of atoms all stuck together like this, you can form a big solid material like a metal or a crystal. The way the atoms are arranged and how strong their bonds are affects the properties of the material - like how hard it is, or how well it conducts electricity.

Tight binding is important because it helps explain why materials behave the way they do. We can use it to predict how a new material might behave before we even make it, which is super useful for things like designing new electronics or materials for space exploration!