Hi everyone,
In order to calculate the excess chemical potential of an adsorbed molecule onto the surface, I need to estimate the free energy by gradually decoupling it. To do so, I used the hybrid pair style to assign lj/cut/coul/long potential to the surface atoms and lj/cut/soft to the atoms in the molecule, and specified the required coefficients of each pair in the input file. To equilibrate the system within an NPT ensemble, I started with a lambda vaue of 1. However, I receive the error “Illegal pair style command”. Could you please help me find out what the problem is?
When using only the lj/cut/coul/long potential, there is no such issue. So as an alternative approach, is it ok if I change the epsilon value of the test atoms manually in several runs (by factors of 0.0 to 1.0), and then do the subsequent calculations to obtain the free energy?
I’d truly appreciate your response.
Thanks in advance.
Hi everyone,
In order to calculate the excess chemical potential of an adsorbed molecule
onto the surface, I need to estimate the free energy by gradually decoupling
it. To do so, I used the hybrid pair style to assign lj/cut/coul/long
potential to the surface atoms and lj/cut/soft to the atoms in the molecule,
why lj/cut/soft and not lj/cut/coul/long/soft?
and specified the required coefficients of each pair in the input file. To
equilibrate the system within an NPT ensemble, I started with a lambda vaue
of 1. However, I receive the error "Illegal pair style command". Could you
please help me find out what the problem is?
does your lammps executable contain the lj/cut/soft pair style? (run
the executable with the -h flag to find out).
if not, then the pair style and its arguments will be added as
arguments to the previous pair style command in the hybrid pair_style
definition and thus trigger the illegal pair style command.
if yes, then check the arguments for the pair style definition carefully.
axel.