In characteristic x-ray intensity calculations, the total L spectrum c
an be represented by separate spectra from L1, L2 and L3 subshell tran
sitions. The expressions presented here take into account the ionizati
on not only of the L1, L2 and L3 subshells but also of the K shell. Th
e approximating polynomials for the calculation of the radiative trans
ition probability and the Koster-Kroning transition probability are de
rived. Examples are presented of intensity calculations in multi-compo
nent systems using the TEREN program.