epsilon in sw potential

Dear Lammps dev

I am trying to implement the boron parameters of sw potential (P.B. Rasband, P. Clancy, B.W. Roberts, J. Appl. Phys. 84 (1998) 2471) into LAMMPS. However, in the paper it does not have the value of epsilon, how can I derived the epsilon coefficient?

regards
min

Contact the authors?

Steve