Dissociative recombination of H and D.

Compared with earlier years, the dissociative recombination of [Formula: see text] has not been very actively studied in recent years. New results from afterglow experiments are quoted and compared with results from ion storage rings and theory. New results for [Formula: see text] are discussed. This article also contains some historical remarks on hydrogen and its importance for the advancement of physics and chemistry. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H, H and beyond'.