Many-body multipartitioning perturbation theory (MPPT) was applied to calculate the potential energy of 11 lowest electronic states of the NaRb molecule, A,C 1Σ+-X 1Σ+, B,D 1Π-X1Σ+, D 1Π-A 1Σ+ and D 1Π-B 1Π transition dipole moments, as well as nonadiabatic L-uncoupling matrix elements between the examined 1Π and four lowest 1Σ+ states for both 23Na85Rb and 23Na87Rb isotopomers. The relevant MPPT ab initio matrix elements and energy curves were converted by means of the approximate sum rule to radiative lifetimes and Λ-doubling constants (q factors) for the particular rovibronic levels of the B 1Π and D 1Π states. The theoretical lifetimes agree well with their experimental counterparts for both B 1Π and D 1Π states. The q factor estimates obtained in the singlet-singlet approximation are in good agreement with the experimental ones for the D 1Π(1<~v′<~12;7<~J′<~50) levels, exhibiting a pronounced difference for the B 1Π state. Considerably better agreement was achieved by accounting for the spin-orbit perturbation effect caused by the near-lying c3Σ+ state. Relative intensity distributions in the D 1Π→X 1Σ+ dispersed fluorescence spectra excited by fixed Ar+ laser lines were measured for v′(J′)=0(44), 1(104), 4(25), 6(44,120), 10(36), and 12(50) D 1Π levels. The experimental intensities and term values were simultaneously embedded in the nonlinear least-square fitting procedure to refine the D 1Π potential.
Energy and radiative properties of the low-lying NaRb states
CIMIRAGLIA, Renzo
2001
Abstract
Many-body multipartitioning perturbation theory (MPPT) was applied to calculate the potential energy of 11 lowest electronic states of the NaRb molecule, A,C 1Σ+-X 1Σ+, B,D 1Π-X1Σ+, D 1Π-A 1Σ+ and D 1Π-B 1Π transition dipole moments, as well as nonadiabatic L-uncoupling matrix elements between the examined 1Π and four lowest 1Σ+ states for both 23Na85Rb and 23Na87Rb isotopomers. The relevant MPPT ab initio matrix elements and energy curves were converted by means of the approximate sum rule to radiative lifetimes and Λ-doubling constants (q factors) for the particular rovibronic levels of the B 1Π and D 1Π states. The theoretical lifetimes agree well with their experimental counterparts for both B 1Π and D 1Π states. The q factor estimates obtained in the singlet-singlet approximation are in good agreement with the experimental ones for the D 1Π(1<~v′<~12;7<~J′<~50) levels, exhibiting a pronounced difference for the B 1Π state. Considerably better agreement was achieved by accounting for the spin-orbit perturbation effect caused by the near-lying c3Σ+ state. Relative intensity distributions in the D 1Π→X 1Σ+ dispersed fluorescence spectra excited by fixed Ar+ laser lines were measured for v′(J′)=0(44), 1(104), 4(25), 6(44,120), 10(36), and 12(50) D 1Π levels. The experimental intensities and term values were simultaneously embedded in the nonlinear least-square fitting procedure to refine the D 1Π potential.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
