  A new concept of the available force in long-range interaction complex
systems is proposed. The relationship between the available force in different
time intervals and the interaction parameters of complex systems is described.
It is found that when the interaction parameters satisfy a determined
condition, the trajectory that the velocity is divergent but the displacement
is convergent can be well described and that the long-range interaction,
anomalous diffusion, and q-Gaussian type distribution of complex systems can
also be well described by the interaction parameters in different cases. In
addition, by utilizing the velocity of time series randomly and analyzing its
probability distribution of displacement, it is explained that when there
exists the long-range interaction in complex systems, the fat-tail
distributions will exhibit. The results obtained show that the relationship
between the available force and the interaction parameters may be used to
investigate the statistical physical properties in long-range interaction
complex systems.
