Over the past decade we chemists have witnessed a tremendous increase in our capability
to carry out quantum chemical calculations of a size that could hardly have been imagined …

An extension of the multiconfigurational second-order perturbation approach CASPT2 is
suggested, where several electronic states are coupled at second order via an effective …

New basis sets of the atomic natural orbital (ANO) type have been developed for the main
group and rare gas atoms. The ANO's have been obtained from the average density matrix …

In this paper, we identify the most efficient decay and isomerization route of the S1, T1, and
S0 states of azobenzene. By use of quantum chemical methods, we have searched for the …

New basis sets of the atomic natural orbital (ANO) type have been developed for the atoms
Li–Fr and Be–Ra. The ANOs have been obtained from the average density matrix of the …

While density functional theory (DFT) has been proven to be extremely useful for the
prediction of thermodynamic and spectroscopic properties of molecules, to date most …

Experimental and theoretical data are provided for a set of 11 pericyclic reactions of
unsaturated hydrocarbons. Literature experimental data are evaluated and standardized to …

Starting from the 1980s and onwards, Valence Bond theory has been enjoying renaissance
that is characterized by the development of a growing number of ab initio methods, and by …

Potential-energy profiles along the minimum-energy reaction path for intramolecular proton
transfer in the 1ππ* excited state have been calculated for the title compounds. The …

Most interpretations of the magnetic coupling J between two unpaired electrons rest upon
simple valence models that involve essentially the ferromagnetic direct exchange …