# Equation of State Calculation in Lammps

Dear Lammps Users,

I want to do a equation of state calculation, since I do not know of some fancy function or routine which can do that in lammps, I want to proceed the following way:

1. Take the desired structure and get it minimum energy
2. Expand the lattice constant a bit and minimize the energy of this structure and run nvt at 10 K to get relaxed coordinates.
3. Start step 3 from 2 and follow the same procedure and repeat.

So this will give a number of volumes and their corresponding energies.

The problem, is, I do not know how to change the lattice length in lammps and I am using my own custom data file, so I need to somehow modify the lattice parameters from a previous run to get the minimum energy at desired configuration.

If anybody has does this calculation in Lammps before, may be they can share the script with me, or tell me about some function which can do this job.

Your help will be very much appreciated, and I sincerely thank you for your time to read my problem, and considerate enough to reply to it.

Thanks

Dear Lammps Users,

I want to do a equation of state calculation, since I do not know of some
fancy function or routine which can do that in lammps, I want to proceed
the following way:

1. Take the desired structure and get it minimum energy
2. Expand the lattice constant a bit and minimize the energy of this
structure and run nvt at 10 K to get relaxed coordinates.
3. Start step 3 from 2 and follow the same procedure and repeat.

So this will give a number of volumes and their corresponding energies.

The problem, is, I do not know how to change the lattice length in lammps
and I am using my own custom data file, so I need to somehow modify the
lattice parameters from a previous run to get the minimum energy at desired
configuration.

If anybody has does this calculation in Lammps before, may be they can
share the script with me, or tell me about some function which can do this
job.

​http://lammps.sandia.gov/doc/change_box.html​