Hi
In my simulation, I used EAM\Alloy instead of EAM. and with fixed boundary conditions. Now, after optimization, the size and volume of spacemen will increase and the simulation will be difficult. Where do you think the problem is?
Impossible to say for certain without knowing more details. One can only speculate. For example:
Have you checked whether your eam/alloy potential has been parameterized to represent the pure element under your simulations conditions. If not, it may not be suitable. Empirical potentials are rarely very transferable and often have to strike compromises on what properties to represent well and which not so well.