This graphic shows a theoretically predicted exotic molecule made of two rubidium atoms, whose size is around a thousand times greater than ordinary diatomic molecules. The molecule's electron density, shown in the figure, resembles a trilobite, a creature that dominated life on Earth hundreds of millions of years ago.
The existence of this molecule was predicted by Chris H. Greene of the University of Colorado Boulder, Alan S. Dickinson of the University of Newcastle, and Hossein R. Sadeghpour, a staff scientist at the Institute for Theoretical Atomic and Molecular Physics (ITAMP) at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., in a paper published in Physical Review Letters, volume 85, number 12, pp.2458-2461 (2000). This is a color version adapted from Fig.3 of that reference.
Green received a grant from the National Science Foundation in 2000 for his work in this study, performed at the Joint Institute for Laboratory Astrophysics (JILA) at CU-Boulder. (Date of Image: May 2000)
Credit: Chris H. Greene, Physics Department and JILA, University of Colorado Boulder