THEORETICAL ASPECTS OF ELECTRON CAPTURE BY C~(6 ) AND O~(8 ) FROM H,He AND H_2

Many theoretical approaches to electron capture by C~(6 ), a nd O~(8 ) fromthe targets H,He and H_2 are discussed from the practical stand point at thepresent stage.The validity of several representative methods for the calcul-ation of total and state selective partial cross sections is given. For the total cross section in many theoretical methods can be appliedand give reasonable results.For the state selective partial cross section for adominant channel at low impact velocities manylevel coupled channel calcul-ations can be used and give reliable results,if it belongs to a dominant cha-nnel.