From: David Vanderbilt <dhv@physics.rutgers.edu> Date: Sat, 17 Jan 1998 20:25:17 GMT (5kb)
Authors:
David Vanderbilt (Department of Physics and Astronomy, Rutgers University),
R.D. King-Smith (Molecular Simulations Inc., San Diego, CA)
Comments: 6 pages. Uses REVTEX macros. Also available at
this http URL
Subj-class: Materials Science
An expression is given for the electronic polarization of an insulating crystal within the ultrasoft pseudopotential scheme. The pseudopotential charge-augmentation terms modify the usual Berry-phase expression, and also give rise to a second term that takes the form of a conventional expectation value.