  We present a systematic statistical mechanical analysis of the conformational
properties of a stiff polyelectrolyte chain with intrachain attractions that
are due to counterion correlations. We show that the mean-field solution
corresponds to an Euler-like buckling instability. The effect of the
conformational fluctuations on the buckling instability is investigated, first,
qualitatively, within the harmonic (``semiclassical'') theory, then,
systematically, within a 1/d-expansion, where d denotes the dimension of
embedding space. Within the ``semiclassical'' approximation, we predict that
the effect of fluctuations is to renormalize the effective persistence length
to smaller values, but not to change the nature of the mean-field (i.e.,
buckling) behavior. Based on the 1/d-expansion we are, however, led to conclude
that thermal fluctuations are responsible for a change of the buckling behavior
which is turned into a polymer collapse. A phase diagram is constructed in
which a sequence of collapse transitions terminates at a buckling instability
that occurs at a place that varies with the magnitude of the bare persistence
length of the polymer chain, as well as with the strength and range of the
attractive potential.
