title: Polarisation charge switching through the motion of metal atoms trapped in fullerene cages.
abstract: The formation of an endohedral fullerene can lead to charge transfer and the generation of a trapped positively charged metal ion. Using Ca@C60 and [Ca@C60](+) endohedral fullerenes as models, density functional theory calculations predict that the motion of a calcium ion within a fullerene is accompanied by large changes in electron density on the surrounding carbon cage. In the case of [Ca@C60](+), partial atomic charge distribution on the carbon cage is split between hemispheres into regions of positive and negative charge as Ca(n+) moves inside the fullerene cage (non-integer n strongly depends on position of the ion). It is proposed that within tethered fullerene cages the movement of partial atomic charge could form the bases of a molecular polarisation storage bit, and that adopted in the form of [Ca@C60](+) the presence of an overall charge may offer a route to either optical or electronic control.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK. Elena.Bichoutskaia@nottingham.ac.uk.
authors.forename: G
authors.initials: G
authors.lastname: Raggi
authors.forename: A J
authors.initials: AJ
authors.lastname: Stace
authors.forename: E
authors.initials: E
authors.lastname: Bichoutskaia