Properties of the B+-H2and B+-D2complexes: A theoretical and spectroscopic study

Globally Accurate Potential Energy Surface for BH2+2(13A') Using the Switching Function Formalism

A great number of ab initio energy points are calculated using the aug-cc-pV(Q,5)Z basis sets at the multireference configuration interaction level and extrapolated to the complete basis set limit. An exact three-dimensional potential energy surface of the ground-state BH₂⁺ is obtained. A switching function is developed to model the transition of B⁺(³P) to B⁺(¹S) to guarantee the reliable behavior at B⁺(³P) + H₂(X¹∑_g⁺) and BH⁺(X²∑⁺) + H(²S) dissociation limits. The various topographic features of the new global potential energy surface are discussed in detail, showing a good agreement with the previous results from the theory. The quasi-classical trajectory method is utilized to calculate the integral cross sections of the B⁺(³P) + H₂(X¹∑_g⁺) (v = 0, j = 0) → BH⁺(X²∑⁺) + H(²S) reaction, which can provide another support for reliability of the title potential energy surface.

Complexes of Alkali Metal Cations and Molecular Hydrogen: Potential Energy Surfaces and Bound States

Complexes between metal cations and molecular hydrogen are systems quite amenable for precise spectroscopic and theoretical studies, and at the same time, they are relevant for applications in hydrogen storage and astrochemistry. In this work, we report new intermolecular potential energy surfaces and rovibrational states calculations for complexes involving molecular hydrogen and alkaline metal cations, M⁺-H₂ (M⁺ = Na⁺, K⁺, Rb⁺, Cs⁺). The intermolecular potentials, formulated in an internally consistent way to emphasize differences in the properties of the systems, are represented by simple analytical expressions whose parameters have been optimized from comparison with accurate ab initio calculations. Properties of the low-lying bound states-binding energies, frequencies, and rotational constants-are compared with previous measurements or computations and an overall good agreement is achieved, supporting the reliability of the present formulation. Variations of these properties as a function of the cation size and isotopic substitution, with a proper sequence of ortho and para rotational levels, are also discussed.

Ab Initio Characterization of the Electrostatic Complexes Formed by H2 Molecule and Cr(+), Mn(+), Cu(+), and Zn(+) Cations

Equilibrium structures, dissociation energies, and rovibrational energy levels of the electrostatic complexes formed by molecular hydrogen and first-row S-state transition metal cations Cr(+), Mn(+), Cu(+), and Zn(+) are investigated ab initio. Extensive testing of the CCSD(T)-based approaches for equilibrium structures provides an optimal scheme for the potential energy surface calculations. These surfaces are calculated in two dimensions by keeping the H-H internuclear distance fixed at its equilibrium value in the complex. Subsequent variational calculations of the rovibrational energy levels permits direct comparison with data obtained from equilibrium thermochemical and spectroscopic measurements. Overall accuracy within 2-3% is achieved. Theoretical results are used to examine trends in hydrogen activation, vibrational anharmonicity, and rotational structure along the sequence of four electrostatic complexes covering the range from a relatively floppy van der Waals system (Mn(+)···H2) to an almost a rigid molecular ion (Cu(+)···H2).

σ Bond activation through tunneling: formation of the boron hydride cations BHn+ (n = 2, 4, 6)

The network of H₂ additions to B⁺ and subsequent insertion reactions serve as a tractable model for hydrogen storage in elementary boron-containing compounds.