delta-Bi1.6Ho0.4O3, is cubic, Fm3m, with a=5.5291(5) Angstrom, V=169.03(3) Angstrom(3), D-calc=8.838 g/cm(3), D-measured (powder technique)=8.607 g/cm(3), with Z=2. Rietveld profile refinements on high resolution X-ray diffraction data give R-p=0.143, R-wp=0.188, R-(I,R-HKL)=0.090, R-(expected)=0.078 confirming the earlier results on the structure of this phase to have a fluorite type lattice with highly disordered oxygen sublattice. Strain and crystal size analysis of all the reflections in the range (2 theta=5-100.94 degrees) from holmium doped bismuth sesquioxide were carried out and compared with the results of the simulated whole powder pattern of Bi2O3 for alpha and delta phases. These results provide pointers to the possible mechanism of stabilization of delta phase on holmium substitution.