Stark-Zeeman hyperfine structure of (HBr)-Br-79 and (HBr)-Br-81 by molecular-beam electric-resonance spectroscopy

We used the molecular-beam electric-resonance (MBER) method to measure the Stark-Zeeman hyperfine structure or the molecules (HBr)-Br-79 and (HBr)-Br-81. For the ground vibrational state (upsilon = 0) and the rotational state J = 1 we obtain for both molecules the electric dipole moment and hypefine structure constants. For the (HBr)-Br-81 molecule we also measured the magnetic molecular constants: g(J) = 0.37122(8), x(parallel to) - x(perpendicular to) = -0-139(7) kHz kG(-2), (sigma(av))(Br) = 2749(40) (ppm), (sigma(parallel to) (-) sigma(perpendicular to))(Br) = 732(14) (ppm), and (sigma(parallel to) - sigma(perpendicular to))(H) = 24(12) (ppm).