  A classical electrostatic solution for polarisation charge on the interface
of a dielectric cavity interacting with an internal point charge is presented.
This solution comes from the Gauss electrostatic potential as a sum of two
terms, the cavity and the point charge, expanded with Legendre polynomials.
Subsequent application of the Dietrich-Newman boundary conditions defines the
problem of emptiness in the inside and isotropic dielectric medium on the
outside of the spherical interface to obtain an equation which describes the
surface charge density on the interface. These results are compared with
quantum chemical calculations using density functional theory for neutral C60
fullerenes. Comparison showed that there was good qualitative agreement between
the classical electrostatic theory and quantum calculations. The polarisation
effect that occurs as a result of the motion of the trapped particle inside the
C60 molecule shows potential for a polarisable nanoswitch which might be used
in nanotechnology as electronic component.
