Help reg. Illegal fix wall/gran command, xtc output

Dear all,

I am trying to write a code to simulate compression of granular particles in a box in 2d. I have to fix the walls and apply force on one of the faces. I downloaded lammps on 22 Feb., 2013.I have three doubts. Here is a part of my script

units si
dimension 2
newton off off
boundary f f p
atom_style sphere
pair_style gran/hertz/history 146520146520 180995475113 5e-5 0 0.5 0

region openbox block 0 0.01 0 0.01 0 20e-6 units box
create_box 1 openbox
create_atoms 1 random 100 3 openbox units box
set region openbox diameter 14e-6 density 1700

pair_coeff * *
timestep 0.005
neighbor 8e-6 bin
#neighbour modify
run_style verlet
fix 1 all enforce2d
fix 2 all wall/gran 146520146520 180995475113 5e-5 0 0.5 0 xplane 0 .01 yplane 0
fix 3 all nve/limit 10e-6
fix force all indent 10 plane y 0.01 hi units box
communicate single vel yes
compute disp all msd
dump 1 all atom 3 output.atom
run 1000000

Firstly, I get an error message which says Illegal fix wall/gran command. I read through the documentation but couldn’t find the reason.
Secondly, I am not able to use dump into xtc file.
Thirdly, I would like to use cylindrical atoms instead of spheres. Is it possible to perform the same simulation using my preferred atom style?
Is it possible to run the simulation till an equilibrium condition if the system attains such a state?
Thanks for all the replies in advance.

Firstly, I get an error message which says Illegal fix wall/gran command. I read through the documentation but couldn’t find the >reason.

yplane takes 2 args, you have 1

Secondly, I am not able to use dump into xtc file.

there is no dump xtc command in your script - did
you compile with the XTC package? What is the
error you get?

Thirdly, I would like to use cylindrical atoms instead of spheres. Is it possible to perform the same simulation using my preferred >atom style?

What is a cylindrical atom? The atom_style
doc page defines the atom styles LAMMPS supports.
If it’s not there, then you can’t use it. Or you
can add it if you write code for a new atom style.

Steve