Ry = 13.6053923;
Ener[1] = 0;

(* AS  *)
A[11,1] = 1.158 10^9;
g[11] = 3;
Ener[11] = 1.715521*Ry;
Ener[5] = 1.546212 * Ry;
A[5,1] = 2.230 10^9;
g[5] = 3;

(* NIST  *)
A[11,1] = 5.6634 10^8;
g[11] = 3;
Ener[11] = 12398.5 /537.029918 ;
Ener[5] = 12398.5 /584.334 ;
A[5,1] = 1.7989 10^9;
g[5] = 3;

Iji[j_,i_,Te_]:= A[j,i] (Ener[j]- Ener[i]) g[j] Exp[-Ener[j]/Te]

Iji[11,1,0.1]

Iji[11,1,1]

Iji[5,1,1]

Iji[5,1,1]/Iji[11,1,1]

Iji[5,1,22]/Iji[11,1,22]

Iji[5,1,100]/Iji[11,1,100]

1.739681352923256`*2

7.747/1.678

Exp[-(Ener[11]-Ener[5])/1000]Ener[5]/Ener[11]A[5,1]/A[11,1]

rjk[Te_] := 21.2180228438/23.0870186592 Exp[- (21.2180228438-23.0870186592)/Te] (1.7989 10^9)/(5.6634 10^8)

rjk[1]

rjk[22]

rjk[100]

4.365/1.349

20.57/5.949

3.29/0.1598