Abstract
The macroscopic longitudinal wave‐vector‐ and frequency‐dependent dielectric function (MLDF) of a Peierls‐Fröhlich semiconductor with one electron per site is calculated within the 3D‐approach of Lee and Kivelson based on the Su‐Schrieffer‐Heeger model. Local field and exchange effects as well as overlap terms in the calculation of the matrix elements of the charge density are neglected. Conditions for the occurrence of an interband plasmon are presented, which are fulfilled in trans‐(CH)x. Special attention is paid to the q‐dependence of the MLDF and the influence of the interchain hopping.