Normal vibrations, of spherical top molecules or ions of XY6type belonging to Ohsymmetry, have been studied by a number of workers1,2. Cut of the six fundamentals, that they are known to possess3, a set of three gerade modes ν1(a1g), ν2(eg) and ν5(f2g) are Raman active while a set of two—ν3and ν4(f1u) are infrared active while ν6(f2u) is inactive in both Raman and infrared, though it may appear in combination. ν1, ν2and ν3, fundamentals involve stretching of the X-Y bond while the remaining three ν4, ν5and ν6fundamentals are primarily associated With skeletal deformations due to Y-X-Y bending modes. Thus symmetry distribution of vibrations of such molecules or ions in this point group is given by