Atomic force in Materials Studio

Hi all,

May I know what is the force given by Materials Studio when use "Force" in scripting. Is it the force at the end of the dynamics run? If i want to get the average of forces for few steps of the dyanmic run, how could i script it in Perl?

Moreover, when i get the force-displacement curve for CNT under compression, i noticed that force is oscillating as can be seen in the figure below. May I know the reason for this oscillation?

force-displacement.bmp

Thanks in advance.