Elastic scattering of two Li7 atoms

Interaction potentials for the X g+1 and a u+3 states of Li2 are constructed and used in calculations of the elastic scattering of two Li7 atoms at ultralow temperatures. The extreme sensitivity of the cross sections to the details of the interaction potentials is demonstrated. The calculated elastic and spin-change cross sections are very large, of the order of 10-13 cm2 at zero temperature. The predicted scattering length for the triplet state is negative with a value of -17.2a0. Pronounced shape resonances appear at energies of 4.9×10-8 a.u. in the singlet scattering and 5.5×10-7 a.u. in the triplet scattering.