ON THE CALCULATION OF C4(-EXCITED STATES() (4, 4) DOUBLY)

We study S-1(e)(4, 4) and D-1(e)(4, 4) resonant states of C4+. Some di fferences between the widths obtained in Feshbach and complex-scaling approaches are analysed in detail in the case of S-1(e)(4, 4) resonanc es. We show that, for C4+(4, 4) states located below the N = 3 thresho ld, the complex-scaling approach gives the perturber parameters when d eveloped in small basis sets. This paper illustrates the relation betw een the concept of autotransfer to Rydberg states, proposed recently i n the collisional context, the quantum defect theory and the complex-s caling approaches.