Question on tersoff parameters

Dear LAMMPS users,

I have a very serious problem on building a correct data file for Tersoff potential. Suppose that I want to build it for a system of two type atom, i.e. A and B. It is obvious that data for ( A A A ) and ( B B B ) rows are available in paper. But, how about other 6 rows of data ? I mean ( A A B ) , … (B B A ). I tried to understand the logic behind it. But, for example in SiC so many parameters are equal with 0. However, when I go through BNC m and check for example ( B B C ), zeros terms are not in agreement with ( Si Si C ) for example. Any comment please ?