I about to determine the bulk properties of 7 different types of stainless steel (grades 304, 308 and 309) that am determine its bulk modulus and all my efforts seems futile.
i Can't really understand what you are trying to explain.
Regarding LAMMPS input file you can visit the LAMMPS documentation section to really understand how to produce a lammps Input file. Download some examples and open files to look at how the structure of file is and what things are necessary.
I have Fe-Ni-Cr alloy, Stainless steels types SS304, SS308, SS309 and SS316 and I am to determine the mechanical damage if subjected to irradiation at pressure of 25MPa and Temperature range of 280-500 degree celcius