The Lennard-Jones (LJ) and Improved Lennard-Jones (ILJ) potential models have been deeply tested on the most accurate CCSD(T)/CBS electronic energies calculated for some weakly bound prototype systems. These results are important to plan the correct application of such models to systems at increasing complexity. CCSD(T)/CBS ground state electronic energies were determined for 21 diatomic systems composed by the combination of the noble gas atoms.
View Article and Find Full Text PDFIn this work, we calculate the rovibrational energies and spectroscopic constants for the systems formed by ammonia (NH) and noble gases (Ng=He, Ne, Ar, Kr and Xe). For the spectroscopic constant calculations, we used two different methods: Dunham and another one that use rovibrational energies (here calculated by discrete variable method). In both cases, we used the improved Lennard-Jones potential energy curves (PECs).
View Article and Find Full Text PDFThis work presents a detailed study concerning the quantum isotope effects on the H+Li[Formula: see text] reaction, when the hydrogen is replaced by muonium, deuterium, and tritium. To verify such effects on these isotope reactions, it was applied an accurate time-independent quantum scattering approach to determine the dynamic properties, such as state-to-state probabilities as a function of the total energy, the product energetic distribution, and the contribution of the ro-vibrational excitation on the reaction probabilities. From the obtained results, it was possible to observe a significant increase on the promotion of the H+Li reaction when hydrogen is replaced by tritium.
View Article and Find Full Text PDF