Computational Aspects for Large Chemical Systems

1. 1 STATEMENT OF THE PROBLEM Quantum chemistry judged not from the ever present possibility of unex­ pected developments but on the basis of the achievements in the last fifty years, is predominantly limited to attempts to solve for the energy and expectation values of wave functions representing, in the limit, an exact solution to the Schroedinger equation. Because of well-known dif­ ficulties i...