  The addition of small impurities, such as a single proton charge carrier, in
noble gas clusters has recently been shown to have considerable effects on
their geometries and stabilities. Here we report on a mass spectrometric study
of cationic clusters of N$_2$ molecules and the effects that adding hydrogen,
in the form of D$_2$, has on the systems. Protonated nitrogen clusters formed
by the breakup of D$_2$ are shown to have similar behaviors as protonated rare
gas clusters. For larger systems consisting of different mixtures of intact
N$_2$ and D$_2$, the different molecular species are found to sometimes be
interchangeable with regards to magic numbers. This is especially true for the
(N$_2$)$_n$(D$_2$)$_m$D$^+$ systems with $n+m=17$, which is particularly
abundant for all measured combinations of $n$ and $m$.
