Contents

04 April 1986
Vol 232, Issue 4746

About The Cover

Cover image expansion

Atomic structure of a silicon crystal surface obtained from a tunneling microscope. The atomic reorganization at the surface of both flat atomic (111) planes and the atomic steps are seen in a 100 by 100 angstrom region. A unit cell of the 7×7 surface reconstruction is highlighted with an expanded computer-generated model above, which accounts for the observed structure. See page 48. [R. S. Becker, J. A. Golovchenko, and B. S. Swartzentruber; artistic assistance provided by J. Drobny and C. Jernstedt, AT&T Bell Laboratories, Murray Hill, NJ 07974]