m-Changing processes resulting from collisions of H(1s) with H(2P{sub o}) below a few eV

The cross sections for m-changing in collisions of H(2P{sub o}) atoms with H(1s) atoms below 2 eV have been studied by means of a two-state, quantum mechanical, coupled-state approach. The molecular states that asymptotically correspond to [H(1s) + H(2P{sub o})] and [H(1s) + H(2P{sub 1})] are h{Sigma}{sub g}{sup +} and i{Pi}{sub g}, respectively. These states are known to possess a small barrier around internuclear distance 4 a{sub o} with a height of 0.4 eV. This barrier is believed to strongly influence the energy dependence of the cross sections for m-changing. Tunneling effects were also studied.