J . Phys. Chem. 1985,89,2145-2150
2145
Quantum Mechanical Molecular Models‘ Michael J. S . Dewar Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712 (Received: August 8, 1984)
The current status of available quantum mechanical molecular models is reviewed with reference to their use in elucidating the mechanisms of chemical reactions.
Introduction As Dirac remarked 60 years ago, the development of quantum mechanics opened up the possibility of predicting chemical behavior a priori. Indeed, it is commonly believed that this could be achieved by solving the relevant Schrodinger or Dirac equationse2 While this goal still remains a distant dream, approximate solutions of the Schrijdinger equation have led to an increasing body of chemically valuable information. The purpose here is to assess the present situation in this rapidly developing branch of theoretical chemistry. The discussion will be confined to studies of chemical reactions and reaction mechanisms because this is the area where good calculations could be of most value, providing information of major importance to chemists that cannot be obtained by experiment. The course of a chemical reaction cannot be observed because the time involved is too short (
