First Ever Complete Solution to the Double Photoionization of H₂

In this week’s edition of Science (Wim Vanroose, Fernando Martín, Thomas N. Rescigno and C. William McCurdy, “Complete Photo-induced Breakup of the H₂ Molecule as a Probe of Molecular Electron Correlation” 2005, 310, 1787) and also in Chemical & Engineering News, the group of Professor C. William McCurdy reports the first and only complete solution of the Schrödinger equation for the double photoionization of the hydrogen molecule (one photon in and two electrons out, followed by the Coulomb explosion of the nuclei).  Experiments done at the Advanced Light Source in Berkeley, which measure this process in complete detail, with the molecule fixed in space at a fixed internuclear distance (that's quite a new trick) appeared in Nature last Fall.  Their exact solution of the quantum mechanics proved that radical changes in the angular patterns of the electrons with small changes in bond distances have to be due to changes in electron correlation as the molecule vibrates.  This development may open the door to a new kind of X-ray spectroscopy that effectively measures the effects of electron correlation in a bond directly.