add a constant force to each atom in real units

Dear all
I want to model poisell flow in lammps. I am using “real units”. I want to add a constant force (i.e. 5 pN) in x direction to each atom .
I know 5 pN is equal to 0.072 Kcal/Angstrom. But we know the force unit in “real units” is Kcal/Angstrom-mole. So, what is the correct force when i use “fix addforce fx 0 0” command in “real units” if i want to add 5pN in x direction to each atom in my group? (i mean what is fx? 0.072 or 0.072/6.022e23 or 0.072*6.022e23?)

Use 0.072. 5 pN is 0.072 Kcal/mol/angs not kcal/angs

0.072 kcal/angs = 3.02 e12 N