[lammps-users] About table potentials

Hi All! I want to use my own potential by pair_style table command.

For example:

# Morse potential for Fe (one or more comment or blank lines)
MORSE_FE (keyword is first text on line)
N 500 R 1.0 10.0 (N, R, RSQ, BITMAP, FPRIME parameters)
1 1.0 25.5 102.34 (index, r, energy, force)
2 1.02 23.4 98.5
500 10.0 0.001 0.003

I have index, r and energy.
But I do not understand what is the force.

The derivative of energy, i.e. -dE/dr