Multireference-configuration interaction MRD-CI calculations were carried out in detail to ascertain the spatial structures and the ground electronic states of Ž . q Ž . q He H and He H clusters, together with their lower-lying excited electronic states. Ž . q The existence of a structural chromophore in the form of the linear He-H-He ionic species is clearly seen and its relationship with the computed structures where further helium atoms are added in the large clusters is discussed. Suggestions are made on the possible shell-like buildup of the protonated clusters as the number of He atoms is increased.