protium

Also contains definitions of: protide, protio
https://doi.org/10.1351/goldbook.P04903
A specific name for the atom 1H. The @C00907@ 1H+ is a @P04906@, the species 1H is a protide @A00358@, and 1H is the protio group. The word @P04906@ should not be used for H+ in its natural abundance.
Source:
PAC, 1988, 60, 1115. (Names for hydrogen atoms, ions, and groups, and for reactions involving them (Recommendations 1988)) on page 1116 [Terms] [Paper]