| Popis: |
The spin-orbit coupling constant, A(r), as a function of internuclear distance (r) was computed for the X2Π state of OH, using the microscopic spin-orbit Hamiltonian, extended basis sets, and extensive configuration-interaction wavefunctions. Our best theoretical results are in excellent agreement with the “experimental” A(r) functions deduced from an inversion of the observed Av. Our calculated first-order contributions to Av, v ≤ 10, obtained by vibrationally averaging our theoretical A(r) function using the X2Π RKR potential, differ from experiment by less than 0.12%. A minimum occurs in the Av at v = 7 in agreement with experiment, reflecting the local minimum in A(r) near 2.8 bohr. The second-order contributions to Av are only about 0.1% for v ≤ 10. They arise mainly from the A2Σ+ state for the lower vibrational levels, but each of the A2Σ+, B2Σ+, (1)2Σ−, (1)4Σ−, and (1)2Δ states contributes significantly for higher vibrational levels. Spin-orbit centrifugal distortion parameters, ADv and aDv, are reported for v ≤ 6. The theoretical ADv are also in excellent agreement with experiment when the “experimental” A(r) function has the same slope at the equilibrium separation as that obtained from the effective spin-rotation constants of OH, OD, and OT. |
