force-field

Hi dear
I’m new user of lammps.I have some problem.I should use amber for methane in my program. but i dont know how I use it.for example in pair_style and pair_coeff I dont know how I explain it.
neda

You should start here: http://lammps.sandia.gov/doc/Section_howto.html#howto_3

Hi,

have you looked at this how to:

http://lammps.sandia.gov/doc/Section_howto.html#howto_3 ?

I also think you should check Andrew Jewett's *moltemplate* tool. It has an example of using AMBER force field in lammps.

Oleg.

16.09.2013, 15:28, "neda eskandari" <[email protected]>:

The real question is: Are you new to Lammps or to atomistic simulations in general? In any case you should understand well how the Amber FF works (its formulation) this first time. Methane is a simple molecule thus once you know how to input the FF params into Lammps, should not take you a long time to complete the task.

Whenever possible, always try to validate the correctness of your procedure. One way to do it could be to use the Amber96 params in your FF Lammps construction, and then compare it to the one obtained via

Towhee (http://towhee.sourceforge.net/). In Towhee you can build a molecule like Methane using Towhee’s internal molecular assembler, assign the Amber96 params to it and then write out input files for Lammps. Of course you’ll have to install Towhee in your PC and learn how to use it. Yes, this will be more work for you. Yet, if you manage to do it all you’ll be more in control of your knowledge, agenda and who knows, with a bit of practice you could go form inquirer to active contributor of this forum.

Carlos