LAUSR

Abstract Highly accurate variational calculations, based on a few-parameter, physically adequate trial function, are carried out for the hydrogen molecule  H2 in inclined configuration, where the molecular axis forms an angle θ with respect to the direction of a uniform constant magnetic field B, for B = 0 , 0.1 , 0.175 and 0.2 a.u. Three inclinations θ = 0 ∘ , 45 ∘ , 90 ∘ are studied in detail with emphasis to the ground state 1g. Diamagnetic and paramagnetic susceptibilities are calculated (for θ = 45 ∘ for the first time), they are in agreement with the experimental data and with other calculations. For B = 0 , 0.1 and 0.2 a.u. potential energy curves E vs R are built for each inclination, they are interpolated by simple, two-point Pade approximant Pade[2/6](R) with accuracy of not less than 4 significant digits. Spectra of rovibrational states are calculated for the first time. It was found that the optimal configuration of the ground state for B ≤ B c r = 0.178  a.u. corresponds always to the parallel configuration, θ = 0 , thus, it is a 1Σg state. The state 1g remains bound for any magnetic field, becoming metastable for B > Bcr, while for Bcr