abnormal value of elastic constant

Dear all and lammps-users,
I am trying to calculate elastic constant of Ti and I am using the Lammps-example in,elastic file . I got abnormal values for C66, C44 which is more than 50% error of the experimental values. I dont know where I made mistake. I am exactly using Adian’s example of elastic constant.
Any help will be appreciated.

It could simply be that the potential you are using does not
reproduce elastic constants. I.e. it has nothing to do
with LAMMPS or how you are running it.