When you picture a snowflake, you probably envision a six-sided shape. Because of the angle of the bonds between hydrogen and oxygen in water, that geometry is greatly favored over other forms. However, snowflakes come in other shapes besides hexagons. For example, there is pentagonal ice. A team of scientists led by the London Centre for Nanotechnology (LCN) discovered a linear chain built from ice pentagons. The chains were formed on a nanoscale across a flat copper surface. Scanning tunneling microscopy was used to image them. While you shouldn't expect to see pentagonal snowflakes any time soon, the research might be used to find new materials to initiate nucleation of water to form clouds and precipitation and also to better-understand how these processes occur naturally.