Dear all,
I want to run NEB calculations on a slab which is shear strained. And I want to do it for different strains so I want to use a loop.
To strain my system, I am using fix addforce. But I am not able to run NEB minimization (or a simple minimization) with that fix.
I am adding the keyword energy with a variable which defines the extra energy coming from the extra force.
But I get the error “ERROR: Variable for fix addforce is invalid style” so I am apparently not doing it the proper way.
Here is my scrpit in which instead of running an NEB I just carry out a simple minimization (to simplify the problem):
Dear all,
I want to run NEB calculations on a slab which is shear strained. And I
want to do it for different strains so I want to use a loop.
To strain my system, I am using fix addforce. But I am not able to run NEB
minimization (or a simple minimization) with that fix.
I am adding the keyword energy with a variable which defines the extra
energy coming from the extra force.
But I get the error "ERROR: Variable for fix addforce is invalid style" so
I am apparently not doing it the proper way.
no, you need to do the energy computation for each atom individually with
an atom style variable, as indicated by the quote from the fix addforce
documentation below:
Note that when the *energy* keyword is used during an energy minimization,
you must insure that the formula defined for the atom-style *variable*
<http://lammps.sandia.gov/doc/variable.html> is consistent with the force
variable formulas...
axel.