The correlation of optical and structural measurements for chromium doped elpasolite crystals were presented to analyze the influence of site-symmetry and electron phonon coupling in elpasolite crystals. X ray and neutron scattering measurements coupled to polarized single crystal Raman spectroscopy were used to probe the site symmetry, coordination geometry and structural changes in the crystals. The shift in the bulk mode frequency was studied to estimate the degree of distortion of the lattice due to site occupation of chromium ion. The analysis suggested that the crystal structure of the elpasolites depended on the radius ratio of ions in the lattice.