There is currently a Tersoff type forcefield in GULP for two-body interactions. If I wanted to implement a Tersoff type potential for three-body interactions what is the syntax in the forcefield file? An example of the two-body is given below:

H  core H  core 86.71200  43.5310 3.78790 1.9800 0.8000 1.0000

Is it simple enough to write:

H core H core H core---- followed by the proper coefficients in the Tersoff forcefield?

Thanks in advance!

NS