You should contact the report authors directly.
This is their AtC work which package is in LAMMPS,
but it's possible the tech report you mention refers
to features or a version that is not publicly released.
J Templeton email is jatempl at sandia.gov
Reese Jones email is rjones at sandia.gov
Steve
Hi Sanghun. The algorithms discussed in that report were implemented in a development version of AtC and haven't yet made it to the released version. We are currently finishing a paper describing the method with a much deeper level of validation. Once it is out, we will add the electrostatic field method to the public release of the AtC package (possibly as soon as February/March if the reviewers are kind). We will post to the LAMMPS user list when we do a release.
best,
Jeremy