I'm reading through the work, Evaluation of Pitzer Ion Interaction Parameters of Aqueous Electrolytes at 25C, 1. Single Salt Parameters, J. Chem. Eng. Data, 1988, 33, 177-184, and this question regards equation 3.

Using

Avogadro's number No = 6.022e23

Density of water at 25C dw = 997 kg/m3

Electron charge e = 1.602e-19 C

Dielectric constant of water at 25C D = 78.55 * 8.854e-12 C^2/J

Boltzmann constant k = 1.38e-23 J/K

Temperature at 25C T = 298.15K

I get A^\phi = 1/3 * (1.9422e12)*(8.4935e-13) = 0.549sqrt(kg) which is

not their 0.392.

Do you have any ideas?