  Molecular hydrogen is a benchmark system for bound state quantum calculation
and tests of quantum electrodynamical effects. While spectroscopic measurements
on the stable species have progressively improved over the years, high
resolution studies on the radioactive isotopologues $\rm{T_2}$, $\rm{HT}$ and
$\rm{DT}$ have been limited. Here we present an accurate determination of
$\rm{T_2}$ $Q(J = 0 - 5)$ transition energies in the fundamental vibrational
band of the ground electronic state, by means of high resolution Coherent
Anti-Stokes Raman Spectroscopy. With the present experimental uncertainty of
$0.02\,\rm{cm^{-1}}$, which is a fivefold improvement over previous
measurements, agreement with the latest theoretical calculations is
demonstrated.
