Regarding C++code link to LAMMPS as a library

first off, please always copy the mailing list on your questions and
don't send them to individual people. thanks.

Dear Sir,

     Thank you for your suggestion.I have bulilt LAMMPS as a library and
also called from external c++ program( simple.ccp program that given in
lammps example file) . It is working fine. I would like to the positive and
negative perturbations of the system simultaneously by fix deformation
command using external c++ program to evalute the potential energy. Is it
possible such deformation, then how will i do such modification in the c++
code or what are the commands .
I would greatly appreciate it if you kindly give me some suggestion on this.

but that is up to *you*. if you don't know what to program, why do you
compile LAMMPS as a library in the first place?

the majority of the LAMMPS code is an example for how to add your own
code, since LAMMPS can be compiled without. thus to find out how you
can change things, you have to *read* the existing source code and see
how you can adapt things for your own purposes. some of the more
elaborate coupling examples can also be instructive, but the bottom
line is that it is up to you how to build your calculation.