Hi,
I’m trying to minimize such system: 2 surfaces of graphene and hydrogene adsorbed on top layer. Then i want to obtain the energy of H-C bonds. But the problem is that after minialization i obtain layer of C and H which is not flat, but rather made of hills and valeys and energy ~1.6 eV instead of less than 1 eV. What i should do to immobilize C atoms? Use ‘fix enforce2d’?
greetings,
Filip
Hi,
I’m trying to minimize such system: 2 surfaces of graphene and hydrogene adsorbed on top layer. Then i want to obtain the energy of H-C bonds. But the problem is that after minialization i obtain layer of C and H which is not flat, but rather made of hills and valeys and energy ~1.6 eV instead of less than 1 eV. What i should do to immobilize C atoms? Use ‘fix enforce2d’?
No. Who says that what you are seeing is wrong for the model you ate using?
Forcing the atoms to not go where they “want” to go is just making your model worse. More likely you need to use a more detailed model, e.g. using DFT.
You can immobilize atoms during a minimization
using fix setforce (not fix enforce2d). However,
as Axel alludes to, don’t be surprised if you don’t
get a true minimum energy by enforcing such a
constraint.
Steve