I am unsure of how to reply to a specific message. This is a reply to
Yes, you need the forces. Your problem (I believe) is your forces should be
positive not negative. Remember, F=-dE/dr NOT F=dE/dr. BEST way to verify
you are using your table right, is to tabulate the LJ potential/force and
compare it to a run where you use the LJ/cut command.
Also, I believe, but not 100% positive, that spline is the most accurate for
table files when comparing to an analytical potential like LJ.