Theoretical Study of the Reactions of Methane and Ethane with Electronically Excited N2(A(3)Σu(+)).

Comprehensive quantum chemical analysis with the usage of density functional theory and post-Hartree-Fock approaches were carried out to study the processes in the N2(A(3)Σu(+)) + CH4 and N2(A(3)Σu(+)) + C2H6 systems. The energetically favorable reaction pathways have been revealed on the basis of the examination of potential energy surfaces. It has been shown that the reactions N2(A(3)Σu(+)) + CH4 and N2(A(3)Σu(+)) + C2H6 occur with very small or even zero activation barriers and, primarily, lead to the formation of N2H + CH3 and N2H + C2H5 products, respectively.

Theoretical study of the reactions of ethanol with aluminum and aluminum oxide.

Quantum chemical calculations with the use of B2PLYP method were carried out to study the reactions of Al and AlO with the C2H5OH molecule. The values of energy barriers were estimated by means of extrapolation to the basis set limit. Examination of the potential energy surface revealed the energetically favorable reaction pathways.

Physical and thermodynamic properties of Al(n)C(m) clusters: quantum-chemical study.

Geometrical structures and physical properties, such as rotational constants and characteristic vibrational temperatures, collision diameter, enthalpy of formation, dipole moment, static isotropic polarizability, and magnetic moment of different forms of Al(n)C(m) clusters with n = 0-5, m = 0-5, have been studied with the usage of density functional theory. Different forms of clusters with the electronic energy up to 5 eV have been identified by using the original multistep heuristic algorithm based on semiempirical calculations and density functional theory. Temperature dependencies of thermodynamic properties such as enthalpy, entropy, and specific heat capacity were calculated for both the individual isomers and the Boltzmann ensembles of each class of clusters.

Theoretical study of the reaction of ethane with oxygen molecules in the ground triplet and singlet delta states.

Quantum chemical calculations are carried out to study the reaction of ethane with molecular oxygen in the ground triplet and singlet delta states. Transition states, intermediates, and possible products of the reaction on the triplet and singlet potential energy surfaces are identified on the basis of the coupled-cluster method. The basis set dependence of coupled-cluster energy values is estimated by the second-order perturbation theory.