Malcolm W. Browne, "Glue of Molecular Existence is Finally Unveiled," New York Times, 7 September 1999.

    A team of chemists and physicists at Arizona State University, Tempe, has produced the first images of atoms in a crystal lattice and the electron bonds that hold them together.  Published in Nature a few years ago, this work provides the sharpest direct images ever made of electronic bonds (known as orbitals).   The shapes of the electron orbitals shown in the photograph--doughnut-like rings and dumbbell-shaped lobes--confirm theoretical predictions of what these bonds should look like in the molecule under study--cuprate (composed of covalent bonds between copper and oxygen atoms).  In a covalent bond, atoms are held together by sharing the electrons found in the outermost orbital (shell) of both atoms (see the illustration below).