Magnetic dipole and quadrupole transitions in the ν + ν vibrational band of carbon dioxide.

This paper aims at the theoretical study of the CO magnetic-dipole ν + ν rovibrational absorption band that was recently detected in the Martian atmosphere. Specific characteristics of the magnetic dipole operator are carefully examined. Our evaluation of the magnetic-dipole line intensities is based on the variational calculations and the use of molecular properties is determined through specially performed ab initio quantum chemical calculations.

Fitting potential energy and induced dipole surfaces of the van der Waals complex CH-N using non-product quadrature grids.

We present an extensive study of the five-dimensional potential energy and induced dipole surfaces of the CH-N complex assuming rigid-rotor approximation. Within the supermolecular approach, ab initio calculations of the interaction energies and dipoles were carried out at the CCSD(T)-F12 and CCSD(T) levels of theory using the correlation-consistent aug-cc-pVTZ basis set, respectively. Both potential energy and induced dipole surfaces inherit the symmetry of the molecular system and transform under the A and A irreducible representations of the molecular symmetry group G, respectively.

Simulation of collision-induced absorption spectra based on classical trajectories and ab initio potential and induced dipole surfaces. II. CO-Ar rototranslational band including true dimer contribution.

This paper presents further development of the new semi-classical trajectory-based formalism described in Paper I [Chistikov et al., J. Chem.

Simulation of collision-induced absorption spectra based on classical trajectories and ab initio potential and induced dipole surfaces. I. Case study of N-N rototranslational band.

This paper presents theoretical formalism and some results of the collision-induced absorption (CIA) spectral simulation based on the classical trajectory analysis. Our consideration relies on the use of ab initio potential energy and dipole moment surfaces for two interacting rigid monomers. Rigorous intermolecular Hamiltonian is represented and used in the body-fixed reference frame.

Comprehensive classical analysis of partition function and some observables for weakly interacting polyatomic dimers.

This paper presents the systematic classical consideration of a statistical averaging procedure that permits the calculation of partition function, equilibrium constant, and some observables for polyatomic dimers composed of weakly interacting rigid monomers. It was shown that the number of independent internal coordinates in a body-fixed frame is a crucial parameter that largely determines the temperature dependence of the partition function irrespective of the kinematic coupling within various degrees of freedom. The kinetic energy was derived for the molecular pair of arbitrary complexity in the body-fixed frame.