Quantum Chemical Models (Nobel Lecture).

The solving of chemical problems to which the answer is unknown or in dispute is the important objective of each theoretical model. How far quantum chemistry has come in this respect is described here for the ab initio concept, which is known to just about every chemist under the name GAUSSIAN. The major advantage of this method is that it can be used to define a way in which one can obtain more accurate results. The target of calculating binding energies and similar values with precisions of 1 kcal mol-1 is not far away for small molecules containing up to fifty electrons.