Diplons in the degenerate regime: exchange and correlation effects

We study the exchange and correlation effects on the ground-state propertie s of dipolar complexes (diplons) formed by the surface electrons on a liqui d helium film and positive ions in the substrate supporting the helium him. We use the self-consistent-field approximation including the short-range c orrelations. The local-field correction, static structure function, exchang e and correlation energies, and collective mode dispersions are calculated for systems with different substrates.