Hi， i want to fix the rotation of polyanions (O atoms will rotation around P) in Na3PO4 during the MD process but the vibration of O atoms should be remained. Any suggestions for this target? And the rotation can be viewed from the iso-surface of anion probability density distribution (attached figure),
Why do you want to do this. If anything, it would suggest that the force field or its parameters have some problems that you want to hide. So I would worry if this is a good idea.
Outside of making the phosphate tetrahedra rigid and then limiting their rotation from fix rigid, I don’t see an existing feature that is capable of specifically what you are asking for. The next best thing to preserve a geometry (which does allow for some movements) would be fix spring/self.
Hi, thanks, I only wanner to know whether this rotation can affect some properties of the materials. So if one property has a great change when the rotation is limited, we can conclude the rotation determine this property. And the fix rigid may ignore the O vibration?
Correlation does not automatically mean causation.
Fix rigid makes those tetrahedra rigid just like its documentation says.