  Effects of quantum phonon fluctuations on the Peierls dimerization in the
one-dimensional molecular crystal model are reexamined by a functional integral
approach. An equation for the dimerization order parameter is obtained within a
one-loop approximation. The destruction of Peierls dimerization is found by
taking the quantum phonon fluctuations into account for the spin-1/2 electron
system. The consistency and discrepancy of the result with previous ones are
discussed.
