Complete active space (CAS) SCF study of the dipole polarizability function for the X 1Σ+ state of LiH

Electronic structure and time-dependent description of rotational predissociation of LiH

The adiabatic potential energy curves of the ¹Σ⁺ and ¹Π states of the LiH molecule were calculated. They correlate asymptotically to atomic states, such as 2s + 1s, 2p + 1s, 3s + 1s, 3p + 1s, 3d + 1s, 4s + 1s, 4p + 1s and 4d + 1s. A very good agreement was found between our calculated spectroscopic parameters and the experimental ones. The dynamics of the rotational predissociation process of the 1¹Π state were studied by solving the time-dependent Schrödinger equation. The classical experiment of Velasco [Can. J. Phys., 1957, 35, 1204] on dissociation in the 1¹Π state is explained for the first time in detail.

Two-photon absorption of the spatially confined LiH molecule

In the present contribution we study the influence of spatial restriction on the two-photon dipole transitions between the X¹Σ⁺ and A¹Σ⁺ states of lithium hydride. The bond-length dependence of the two-photon absorption strength is also analyzed for the first time in the literature. The highly accurate multiconfiguration self-consistent field (MCSCF) method and response theory are used to characterize the electronic structure of the studied molecule. In order to render the effect of orbital compression we apply a two-dimensional harmonic oscillator potential, mimicking the topology of cylindrical confining environments (e.g. carbon nanotubes, quantum wires). Among others, the obtained results provide evidence that at large internuclear distances the TPA response of lithium hydride may be significantly enhanced and this effect is much more pronounced upon embedding of the LiH molecule in an external confining potential. To understand the origin of the observed variation in the two-photon absorption response a two-level approximation is employed.

Far- and Mid-Infrared Emission Spectroscopy of LiH and LiD

High-resolution Fourier transform spectra of LiH and LiD were recorded in the far-infrared region, 100-360 cm-1, and the mid-infrared regions, 800-1200 cm-1 and 2000-3000 cm-1. A total of 261 pure rotational lines and 678 rovibrational lines were measured for the isotopomers 6LiH(D) and 7LiH(D). Molecular constants for the X1Sigma+ ground state in the form of mass-dependent Dunham Yij's and mass-independent Dunham Uij's were determined from a data set of 1476 lines, consisting of our measured line positions and previously reported microwave, millimeter-wave, and infrared lines. An effective internuclear potential for the ground electronic state where the Born-Oppenheimer part is modeled as a parameterized modified-Morse function was also determined from a fit of the data. Copyright 1998 Academic Press.