On the Senftleben-Beenakker Electric Effect in Gaseous Ammonia

to those involving n bonds as well. It is our con­ tention that the constants determined and used in this investigation are universal to all the hydrocar­ bons, be they aliphatic or aromatic. Furthermore, we believe that the technique as used in the deter­ mination of the atomization energies and stable con­ figurations stands unique in its class of semi-empiri­ cal calculations. Be that as it may, lest we mislead the reader with over-enthusiasm, we would like to stress that our methodology of estimating dissociation energies from the calculated atomization energies is not ex­ pected, because of its crude approximations, to be universally applicable. There is reason to believe, however, that the methodology has a greater chance of applicability whenever the ordinary extended Hiickel calculation suggests a stable configuration and whenever nonbonding orbitals are not involved. We certainly agree that many of our assumptions will not, and indeed cannot, pass the test of rigor. But then, why should one expect more rigor from the variants of the Hiickel method when such rigor is not found in the Hiickel method itself?