Electron diffraction study of the structure of the cerium tetrafluoride molecule

Numerous studies of the structure of molecules of the XY4 type in the gas phase have led to the conclusion that the overwhelming majority of these molecules have the tetrahedral configuration. Only in certain cases such as SF4, XeF4, and uranium and thorium halides have any configurations been found with a symmetry lower than T/sub d/. These deviations from T/sub d/ symmetry, which are related to specific features of the electronic structure of these molecules, are very important in the development of a general theory for the structure of inorganic compounds. Here we are presenting results obtained in an electron diffraction study of the CeF4 molecule, for which a deviation of the symmetry from the model of a regular tetrahedron is suggested by data obtained on the deflection of molecular beams in a nonuniform electric field