1 research outputs found
Performance of Different Force Fields in Force Probe Simulations
We present detailed force probe molecular dynamic simulations
of
mechanically interlocked dimeric calix[4]Âarene–catenanes, comparing
the results obtained using three different commonly used force fields
(GROMOS G53a5, OPLS-AA, and AMBER GAFF). The model system is well
characterized as a two-state system consisting of a closed compact
and an elongated structure. Both states are stabilized by a different
hydrogen-bond network, and complete separation of the dimer is prevented
by the mechanical lock of the entangled aliphatic loops. The system
shows fully reversible rebinding meaning that after bond rupture the
system rejoins when the external force is relaxed. We present a detailed
study of quantities determined in simulations using a force ramp,
like the rupture force and rejoin force distributions. Additionally,
we analyze the dynamics of the hydrogen-bond network. We find that
the results obtained from using the different force fields qualitatively
agree in the sense that always the fully reversible behavior is found.
The details, like the mean rupture forces, however, do depend on the
particular force field. Some of the differences observed can be traced
back to differences in the strength of the hydrogen-bond networks