Development and testing of semiempirical methods for the calculation of wavefunctions requires accurate wavefunctions for molecules large enough to be treated by these semiempirical methods yet small enough to be dealt with by a priori techniques. Since theoretical work in this laboratory has primarily involved nitriles it is not unreasonable that some attempt should be made to obtain good wavefunctions for larger nitriles. Acrylonitrile, or vinyl cyanide, is a particularly attractive nitrile for consideration because of the presence of the ethylenic bond as well as the nitrile bond, both of which presumably contribute to some delocalization of the electrons through the molecule. Hence, semiempirical Π-electron methods may be applied to such a molecule as they have been in this laboratory. In addition the acrylonitrile molecule is an interesting molecule for examination by a priori methods since it is a nonlinear molecule. Most of the work on very accurate wavefunctions has so far been confined to linear molecules, and no wavefunctions are available in the literature for the vinyl cyanide molecule.