Método para determinação do grupo pontual de moléculas

Abstract

The present work describes a new method to nd the point groups of molecules, employing concepts more familiar to chemists and physicists, where the point group is found from the following information: (1) The type of rotor which the molecule belongs (spherical, prolate, oblate, linear or asymmetric), (2) The number of symmetrically equivalent atoms, that is, that atoms whose positions are interchanged trough a symmetry operation (ex. the hydrogens in a water molecule), (3) The interatomic distance matrix, (4) The atomic masses and (5) The polygon or polyhedron formed by the symmetrically equivalent atoms. The proposed method allows the identi cation of the full point group of any molecule from a reduced number of symmetry operations. This method has been implemented in a program written in C language and will be incorporated into a code developed for calculations of the intensities of infrared and Raman spectra. The last can explore e ciently the molecular symmetry but doesn't have a routine for automatic identi cation of the molecular point group.