2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28032An 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.6 pages. Uses REVTEX macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#dv_uspolMaterials Sciencetext