Circular dichroism in the double photoionization of molecules

The existence of circular dichroism in the triple differential cross section is shown for the emission of two electrons in the one-step double photoionization of a molecule. Our study reveals that the geometrical requirements for the presence of dichroic effects in the double photoionization of linear molecules are identical to those for atoms. But there are, in general, no restrictions for the presence of dichroism in non-linear molecules because it may now exist for two photoelectrons observed even with equal energies in any of the physically feasible experimental geometries. For illustration, a general procedure for studying dichroism in the double photoionization from the a1 orbital of a Td molecule is discussed.