When an external electromagnetic field is applied, this electron gas can execute collective oscillations about the positive ion core

Theory of Molecular Rydberg States - Page 45 - Google Books Result

books.google.com/books?isbn=1139498606

M. S. Child - 2011 - ‎Science

We know from the discussion in Chapter 1 that they arise from interactions between the positive ion core and the Rydberg electron, which were seen to occur on ...

Clusters and Nanostructured Materials - Page 15 - Google Books Result

books.google.com/books?isbn=1560723785

P. Jena, ‎S. N. Behera - 1996 - ‎Science

When an external electromagnetic field is applied, this electron gas can execute collective oscillations about the positive ion core. These oscillations, known as ...