  Results of Rietveld analysis of the synchrotron XRD data on Pb(Zr_xTi_1-x)O_3
(PZT) for 0.525\leqx\leq0.60 are presented to show the absence of rhombohedral
phase on the Zr-rich side of the morphotropic phase boundary (MPB). Our results
reveal that the structure of PZT is monoclinic in the Cm space group for
0.525\leq x\leq 0.60. The nature of the monoclinic distortion changes from
pseudo-tetragonal for 0.525\leqx\leq0.54 to pseudo-rhombohedral for x>0.54.
