This directory provides BLAS and LAPACK functions used by the USER-ATC and USER-AWPMD packages (and possibly other packages in the future). You should only need to build and use the resulting library in this directory if you want to build LAMMPS with the USER-ATC and/or USER-AWPMD packages and do not have any other suitable BLAS and LAPACK implementation libraries (e.g. using ATLAS, GOTO-BLAS, OpenBLAS, ACML or MKL) installed on your system. Use one of the Makefiles provided to build this library. You may need to edit it for your system. When you are done building this library, one file should exist in this directory: liblinalg.a the library LAMMPS will link against You can then include this library and its path in any packages that need it, e.g. in the lib/atc/Makefile.lammps file. Please note,that this is an *incomplete* subset of BLAS/LAPACK.