The Makefile.lammps file in this directory is used when building LAMMPS with packages that make use of the NetCDF library or its parallel version. For example, the USER-NETCDF package which adds dump netcdf and dump netcdf/mpiio commands.

The file has several settings needed to compile and link LAMMPS with the NetCDF and parallel NetCDF support. For any regular NetCDF installation, all required flags should be autodetected. Please note that parallel NetCDF support is beneficial only when you run on a machine with very many processors like an IBM BlueGene or Cray. For most people regular NetCDF support should be sufficient and not cause any performance penalties.

If you have problems compiling or linking, you may have to set the flags manually. There are three makefile variables

1. netcdf_SYSINC

This is for setting preprocessor options and include file paths. Set -DLMP_HAS_NETCDF, if you have NetCDF installed. Set -DLMP_HAS_PNETCDF, if you have parallel NetCDF installed. You can have either or both defines set. If none of these are set, LAMMPS will compile, but the NetCDF enabled functionality will not be available. In addition you may have to point to the folder with the include with -I/path/to/netcdf/include

Example for a Fedora 24 machine with serial NetCDF installed as netcdf-devel-4.4.0-3.fc24.x86_64 RPM package:

netcdf_SYSINC = -DLMP_HAS_NETCDF -I/usr/include -I/usr/include/hdf

2. netcdf_SYSLIB

This is the setting for all required libraries that need to be linked to.

Example for a Fedora 24 machine with serial NetCDF installed as netcdf-devel-4.4.0-3.fc24.x86_64 RPM package:

netcdf_SYSLIB = -lnetcdf

3. netcdf_SYSPATH

This is the setting for the path of directories with the NetCDF libraries. Typically, this will be of the form -L/path/to/netcdf/lib

In the example from above, it can be left empty, because the Linux distribution provided libraries are installed in a system library location.