3^ L. VEGARD. M.-N. Kl. 



Let us suppose the recombination to take place in one step or, that 

 only one energy quantum of frequency v^ is emitted; then: 



h v^ = J E = h Vj^ 

 or 



Consequently v^ should be equal to the frequency of the absorp- 

 tion edge: 



At an infinite distance the quantnumber r is infinitely great, and 

 V{tpq) vanishes: Putting in equation (25) x = 00 , we get: 



^ = J^ = T^ (".. Pt^ Qt) - "^' i>h-^ Pt, ^/ - J ) 



l=m } ...(28) 



+ s r ^^ ("/' p/' ^/) ~ ^' ("/' Pi—^' "iM 



l = i+l 



where m is the total number of electronic systems of the atom considered. 



In order to calculate v^ we must know the constitution of all the 

 electronic systems surrounding the nucleus, but with certainty we only 

 know the K- and L-system. 



The best way of testing the correctness of the equation (28) would 

 be to calculate v^ for the /^-asorption edge and for very low atomic 

 numbers. In that case we know those systems which contribute most 

 to the frequency j/^, and differences with regard to the outher systems 

 will not have any great effect on the frequency. 



The lowest atomic numbers for which I have found determinations 

 of the absorption edges are N= 26 {Fe) and 28 {Ni). 



Wagner^ gives the following values: 



Fe . . . ^^ = 1,759 ^o^ '^'^• 

 Ni . . . Z^ = 1,502 lO'"* » 



Now we assume a constitution of the electronic system similar to the 

 one indicated in fig. 2 of my previous paper, but with a change of the 

 quant-number of the third and fourth ring. 



The following constitution is adopted : 



' E. Wagner, Phys. Zeitschr. i8 p. 436, 1017. 



