The hexafluorides of sulfur, selenium, tellurium, molybdenum, technetium, ruthenium, rhodium, tungsten, rhenium, osmium, iridium, platinum, uranium, neptunium, and plutonium possessing an octaedral symmetry with the symmetry point group Oh have been briefly analyzed for the molecular structural data and the infrared absorption andRaman spectra. On the basis of group theoretical considerations, potential energy constants have been evaluated by employing a general harmonic force field. The L matrix elements connecting the internal coordinates and normal coordinates have been derived from the symmetrized force constants, G matrix elements, and vibrational frequencies. The Coriolis coupling coefficients of vibration-rotation have also been, in terms of the symmetrized force constants, G matrix elements, and vibrational frequencies, computed for these fifteen hexafluorides, and compared with the available values of experimental investigations. A brief discussion of the results follows.