Kalium

u = 1.6605387313*(10^(-27)); mp = 1.6726231*10^(-27); 
    me = 9.1093897*10^(-31); 
    h = 6.626076*10^(-34); (Subscript[ϵ, 0]) = 8.854188*10^(-12); 
    el = 1.602177*10^(-19); 
    mK = 39.0983 u; μ = me*mK/(me + mK); c = 3 (10^8); g = 5.58; 
    B = 0.5; a = 4.7 (10^(-3)); Z = 19; α = 7.297353 (10^(-3)); 
    Ry = (el^4) me/(8 c (h^3) ((Subscript[ϵ, 0])^2));

(Subscript[E, 4]) = - μ (Z^2) (el^4)/(8 (h^2) ((Subscript[ϵ, 0])^2) 16 )

g = 4/3

g el h/(8 π me)  B /el

g = 2/3

g el h/(8 π me)  B /el

g = 2

g el h/(8 π me)  B /el