Hyperfine structure, lifetime and oscillator strength of V II

•New oscillator strength parameterisation method was successfully applied.•Good agreement between ab initio and experimental values of radiative lifetimes.•Radial integral of the main atomic transitions is determined for the first time.•Oscillator strength values are calculated semi-empirically in a wide wavelength range: 2117-96,000 Å.

In first part of this work we confirm through data computed for the first time the well-founded basis of new experimental constant values for some V II levels, recently measured and published. Furthermore a good agreement is observed between single-step excitation and laser induced fluorescence V II radiative lifetimes found in the literature data and our computed values recurring to ab initio method. In the third part of this study we examined electric dipole transitions. We transformed angular coefficients of the transition matrix from SL coupling to intermediate one using fine structure eigenvector amplitudes, previously determined. Transition integrals, treated as free in the least squares fit to experimental oscillator strength (gf) values, were then extracted; we give the two main deduced values: 〈3d34p|r1|3d34s〉=−3.0346±0.0094 and 〈3d34p|r1|3d4〉=0.8278±0.0026. This procedure, which provides accurate evaluations, differs totally with previous ways using for instance the Thomas-Fermi-Dirac method to compute transition integral values. Finally, for a complete list of permitted transitions from depopulated odd-parity levels, gf values are calculated semi-empirically in a wide wavelength range: 2110-96,000 Å