  Bogoliubov-de Gennes (BdG) equations and the excitation spectrum of a
two-component Bose-Einstein condensate (BEC) are derived with an arbitrary
interaction between bosons, including long-range and short range forces. The
nonconverting BEC mixture segregates into two phases for some two-body
interactions. Gross-Pitaevskii (GP) equations are solved for the phase
segregated BEC. A possibility of boundary-surface and other localised
excitations is studied.
