[lammps-users] phonon wave-packet simulations

Steve,

I am interested in performing phonon wave-packet simulations where I have a system of two different materials divided equally by a single interface. In these simulations I was to create a phonon wave-packet at one end of the device and allow it to propagate to the interface to see how it interacts (transmits or reflects) with the interface. Do you have any ideas for how I can generate this wave packet in lammps?

Thanks,

Nick

If by phonon wave-packet you mean an instantaneous
displacement of a subset of atoms, then look at the
displace_atoms command. If that's not general enough
to do exactly what you want, then a similar command
could be written (or that one extended) that would reset
the position of a group of atoms.

Steve

just a 2 cents comment:

I think you need to give initial velocities and displacements. P. Schelling from U. Central Florida has many papers on the subject. From my limited experience, you’ll need to form the packet in wavevector space and an inverse FFT to get the initial positions and velocities.

Reese

Steve Plimpton wrote: