Accurate calculations of ground and excited states by the MR-AQCC method. Prototype application to the proton transfer in 7-azaindol

The basic formalism of the MR-AQCC method is presented which is basically a size extensivity corrected MR-CI procedure. The correction is applied in form of a diagonal shift which allows easy implementation of the method into any MR-CI programs and makes the calculation on excited states also possible. Accuracy of the method is discussed. To show the applicability of the method we present the first results of our systematic study on the proton transfer in 7-azaindol. We conclude that inclusion of dynamic correlation is essential to get reliable energy differences and potential energy surfaces for this process.