Hi,

I want to run a molecular dynamic process for a gas molecule adsorption in a porous media via GULP. I want to keep the porous crystal rigid while the gas molecule is free to change the coordination. I have made all the flags at the end of coordination points of porous structure to 0 which should make the position fixed but still I have a motion in my structure at the final stage. What should I do to keep it rigid? Is there any other way?

Best regards,

Ahmad