Ab initio study of the X2Π and A2Σ+ states of OH. I. Potential curves and properties

Accurate ab initio CI potential curves and molecular properties are presented for the X²Π and A²Σ⁺ states of OH. Results with known experimental values in parentheses are R_e(X²Π) = 1.841(1.834) bohr, R_e(A²Σ⁺) = 1.906(1.913) bohr, D_e(X²Π) = 4.43(4.63) eV, D_e(A²Σ⁺) = 2.29(2.53) eV, μ(OH,X²Π,ν=0) = 1.634(1.668) D, and μ(OD,A²Σ⁺,ν=0) = 1.861(1.72±0.10) D. Spectroscopic constants calculated from the theoretical potential curves are in satisfactory agreement with experimental results. Other molecular properties studied include quadrupole moments and the electric field gradient at the nuclei.