An electrically charged molecular @M03968@ which may dissociate to form fragments, one or more of which may be electrically charged, and one or more neutral species. A parent ion may be a molecular ion or an electrically charged fragment of a molecular ion.
Orange Book, 2nd ed., p. 205 [Terms] [Book]
PAC, 1991, 63, 1541. (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1549 [Terms] [Paper]