Molecules are closer together in solids than liquids. So why does frozen water expand?

In ice (at 0°C or below), each O atom is surrounded tetrahedrally by four H atoms, two by covalent bonds and two by hydrogen bonds. The structure is rather “open”. Therefore, ice has a greater volume than an equal mass of water at 0°C.

The structure of ice is shown below.

It likes to stretch out and relax when it chills ...

Trapped air.

Water frozen in a vacuum doesn't expand

It would take too long to explain, here:

https://www.thenakedscientists.com/articles/questions/why-does-water-expand-when-it-freezes

I assume because it creates air pockets... There might be a more scientific way of explaining