[lammps-users] differnet energies exist between LAMMPS and Material Studio

Hi, Steve,

In the previous emails, I see somebody posted that the different energies existed between LAMPS and Material Studio for the polymeric materials with the same force field. You said that the difference was caused by the setting of special_bonds. Would you please tell me the default setting of special_bonds for PCFF in materials studio, using which we can get the same result from LAMMPS and material studio?

Thanks in advance.

Regards,
Chen

Would you please tell me the default setting of special_bonds for PCFF in materials studio, using which we can get the >same result from LAMMPS and material studio?

That's a Mat Studio Q - I have no idea.

Steve

2009/9/20 Chen Yu <[email protected]>:

This has worked for me.

lj 0 0 1
coulumb 0 0 1

Vikas

2009/9/20 Chen Yu <[email protected]…1117…>

Hi, Steve,

I have a question on the command "deform". Does this command only simply change the cell box length and let the atoms insides adjust themselves, or rescale the positions of all the atoms directly every step?

Regards
Chen

It can do either. See the remap option on the fix deform command.

Steve

Hi, steve,

I got a trouble when using ave/spatial to calculate the density of the bulk materials (sample :PE). I build the model in Material Studio with a initial density 1 g/cm^3, and then transferred it into LAMMPS, and run a short NVT. I got the density file on X Y Z diractions, and I found the value is about 0.5-0.8 g/cm^3, less than the initial 1 g/cm^3. I send you the attached file, would you please check this for me?

Regards,
Chen

beforemydensityallx.file (6.57 KB)

beforemydensityally.file (6.58 KB)

beforemydensityallz.file (6.56 KB)

densitytest.lammps05 (398 KB)

indensitytest.txt (3.76 KB)

log.lammps (8.63 KB)

I can't debug people's (complicated) input scripts. It's a simple
calculation. Take a snapshot. Find which atoms are in a layer.
Add up their mass. Divide by volume of the layer. You can do
it by hand for a small system. If you think LAMMPS isn't
giving the same answer as you compute, then show me why.

Steve