12398./(1 10^8)

0.00012398000000000002`* 0.365

12398 * 0.365 10^(-8)

ΔE1[Z_, n_, l_]:= Z^2/n^2 13.605698 (Z/137)^2 / n^2 (3/4 - n/(l+1/2) )

ΔE1[1,2,1]

ΔE1[Z_, n_, l_]:= Z^2/n^2 27.21138505/2 (Z/137)^2 / n^2 (3/4 - n/(l+1/2) )

ΔE1[1,2,1]

27.21138505/2

13.605692525`

ΔE1[1,2,0]

ΔE1[1,3,0]

ΔE1[1,3,1]

ΔE21[Z_, n_, l_]:= Z^2/n^2 13.605698 (Z/137)^2 l / (2 n l (l+1/2)(l+1))

ΔE22[Z_, n_, l_]:= Z^2/n^2 13.605698 (Z/137)^2 (-l -1)/ (2 n l (l+1/2)(l+1))

ΔE21[1,2,1]

ΔE22[1,2,1]

ΔE3[Z_, n_]:= Z^2/n^2 13.605698 (Z/137)^2 /n

ΔE3[1,2]

ΔE1[1,2,1]+ΔE21[1,2,1]

ΔE1[1,2,1]+ΔE22[1,2,1]

ΔE1[1,2,0]+ ΔE3[1,2]

0.00005663296095373356`-0.000011326593406181738`

Dirac[Z_,n_,j_]:= 2 13.605698 (137)^2  ( 1/(Sqrt[1+ (Z / 137 / (n - j -1/2 + Sqrt[(j+1/2)^2 - (Z/137)^2]))^2] ) -1 )

Dirac[1,1,1/2]

Dirac[1,2,1/2]

Dirac[1,2,3/2]

Ener[Z_,n_]:=-Z^2/n^2 13.605698

Ener[1,1]+ ΔE1[1,1,0] + ΔE3[1,1]

Ener[1,1]+ ΔE1[1,1,0] + ΔE3[1,1] - Dirac[1,1,1/2]

Ener[1,2]+ ΔE1[1,2,0] + ΔE3[1,2] -  Dirac[1,2,1/2]

Ener[1,2]

ΔE1[1,2,0]

ΔE3[1,2]

Dirac[1,2,1/2]

Ener[1,2]+ ΔE1[1,2,1] + ΔE21[1,2,1] -  Dirac[1,2,3/2]

Ener[1,2]+ ΔE1[1,2,1] + ΔE22[1,2,1] -  Dirac[1,2,1/2]

Dirac[1,2,3/2]-Dirac[1,2,1/2]

ΔE21[1,2,1]-ΔE22[1,2,1]

5.663-1.133