The reaction ${}_{}{}^8{}_{}{}^{}\mathrm{Li}$(α,n${)}^{11}$B is of interest in inhomogeneous big bang nucleosynthesis. A distorted wave Born approximation calculation employing folding potentials is presented for energies below the Coulomb barrier. The recently observed resonance at about 540 keV center-of-mass energy can be reproduced. The astrophysical S factor is calculated for the ground-state transition as well as for the transitions to the first four excited states of ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$. The reaction rate is derived and compared to literature data. The inclusion of the excited states increases the rate by a factor of 1.5 compared to the ground-state transition.

• Received 14 August 1991

DOI:https://doi.org/10.1103/PhysRevC.45.1996