Hydrogen, the most abundant element in the universe, has the lowest density of all gasses. Generally, the clusters in the hydrogen or the hydrogen cluster consist of positively charged ions. But, for the first time, scientists have found negative hydrogen cluster ions in hydrogen. Scientists have seen negative hydrogen cluster ions beyond the simplest possible pairing of one molecule and one ion.
Scientists from the University of Innsbruck in Austria have created the new form of hydrogen that has negatively charged hydrogen clusters. In this new type of hydrogen, each cluster has hydrogen molecules arranged around a negatively charged hydrogen ion. That means a single hydrogen atom has an extra electron at temperatures near absolute zero.
Scientists infused tiny droplets of liquid helium with hydrogen gas. They then attacked droplets through electron beams. Due to this, some hydrogen molecules are converted into negatively charged hydrogen ions. Neighboring hydrogen molecules clustered around the ion, in groups of a few molecules to over 60.
Scientists also determined the structure of the clusters. The clusters are most stable, and most common when molecules filled shells to their capacity. The hydrogen molecules are arranged in shells that revolve around the central ion. In the first shell, the cluster formed an Icosahedron. The icosahedron is a 3-D shape with 12 vertices when 12 molecules filled this shell.