Ab initio relativistic potential energy surfaces of benzene–Xe complex with application to intermolecular vibrations

摘要: The benzene-Xe (BXe) complex in its electronic ground state is studied using ab initio methods. Since this contains the heavy Xe atom, relativistic effects cannot be neglected. We test two different approaches that describe scalar framework of coupled-cluster level theory with single, double, and perturbative triple excitations, used for interaction energy calculations. first one based on small core pseudopotential (PP), second explicit treatment Douglas-Kroll-Hess (DKH) Hamiltonian. A few basis sets are tested PP DKH, each one, analytical potential surface (PES) constructed. It shown difference between PESs determined DKH methods small, if orbitals 4d subshell correlated. select most appropriate approach calculation BXe, respect to accuracy computational cost. optimal includes a Dunning's set benzene monomer larger supplemented by midbond functions. PES obtained such an provides reasonable when compared empirical derived from microwave spectra BXe. theoretical values intermolecular vibrational energies agree within 0.5 cm-1 up overtones. pattern BXe characterized distinct polyad structure.