  We have analyzed the clustering of C IV absorption line systems in an
extensive new catalog of heavy element QSO absorbers. The catalog permits
exploration of clustering over a large range in both scale (from about 1 to
over 300 Mpc) and redshift (z from 1.2 to 4.5). We find significant evidence
(5.0 sigma) that C IV absorbers are clustered on comoving scales of 100 Mpc and
less --- similar to the size of voids and walls found in galaxy redshift
surveys of the local universe --- with a mean correlation function $\xi = 0.42
\pm 0.10$ over these scales. We find, on these scales, that the mean
correlation function at low (z=1.7), medium (z=2.4), and high redshift (z=3.0)
is $\xi=0.40 \pm 0.17$, $0.32 \pm 0.14$, and $0.72 \pm 0.25$, respectively.
Thus, the superclustering is present even at high redshift; furthermore, it
does not appear that the superclustering scale, in comoving coordinates, has
changed significantly since then. We find 7 QSOs with rich groups of absorbers
(potential superclusters) that account for a significant portion of the
clustering signal, with 2 at redshift $z\sim 2.8$. We find that the
superclustering is just as evident if we take $q_0=0.1$ instead of 0.5;
however, the inferred scale of clustering is then 240 Mpc , which is larger
than the largest scales of clustering known at present. This discrepancy may be
indicative of a larger value of $q_0$, and hence $\Omega_0$. The evolution of
the correlation function on 50 Mpc scales is consistent with that expected in
cosmologies with density parameter ranging from $\Omega_0 = $ 0.1 to 1.
Finally, we find no evidence for clustering on scales greater than 100 Mpc
($q_0=0.5$) or 240 Mpc ($q_0=0.1$).
