CeO2 ( potential )

Thanks for your help.. but there is not mentioned any thing about shell
model potential !!!!

OF *COURSE*!!!!!!!

what would be the point of explaining in detail how to implement a
specific model and then not to implement it?

what did you suggest?!

you want it, you have to figure out how to implement it. that is how
everybody else did it that contributed packages or styles to LAMMPS.