Extracting coordinates and energy from a LAMMPS object in C++

LAMMPS LAMMPS Development
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Hello everyone,

I am trying to learn how to use the LAMMPS Library Interface in a C++ code. I am wondering whether it is possible to extract energy or atomistic coordinates from the LAMMPS object…something like, lmp->AtomCoords?

Thanks,
Projesh

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If you have to ask this kind of question and cannot determine the answer yourself from reading the LAMMPS source code, please use the C-library interface: 1. LAMMPS Library Interfaces — LAMMPS documentation

You will save yourself from a whole lot of trouble.

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For those who need help …

– I found coordinates can be accessed using

double **xyz = lmp->atom->x

Mind that it gives you a pointer. Basically, you need to take a look at the /src/atom.h file for accessing the per atom properties.

– The energy can be accessed using,

double lammps_get_thermo(void *handle, const char *keyword);

– (double *) lammps_extract_variable (lmp,“”,“”), for any other variables defined in the script. These functions are listed in the /src/library.h file.