A theoretical description of the radiative decay processes (b 1Σ+, a 1Δ)→X 3Σ− in NF

Abstract

A recently developed methodology based on the Breit–Pauli approximation and the symbolic matrix element method is used to consider the spin-forbidden radiative decay processes, b 1Σ+→X 3Σ− and a 1Δ→X 3Σ− in NF. We report nonrelativistic potential energy curves for the b 1Σ+, a 1Δ, and X 3Σ− states and geometry dependent spin-forbidden transition moments, μ∥ ≡μ0(b 1Σ+0+, X 3Σ−0+), μ⊥ ≡−μ−1(b1Σ+0+, X3Σ−1), and μ1(a 1Δ2, X 3Σ−1) based on large scale MCSCF/CI wave functions (∼5–9×104 CSF’s). Mean values for μ∥, μ⊥, and μ1(a 1Δ2, X 3Σ−1) corresponding to v=0 harmonic oscillator functions are found to be 0.181×10−2, 0.467×10−3, and 0.278×10−3 a.u., respectively. The mean value of the ratio μ∥/ μ⊥ is found to be, 〈μ∥〉0,0/ 〈μ⊥〉0,0 ∼3.87. These results are in good agreement with the available experimental data.