• Reference documentation for spack
• Set the spack environment variables using the command

source /usr/local/spack/share/spack/setup-env.sh

• To see list of all installed spack packages

spack find

• To deconflict multiple packages with the same name (but usually different compilers)

spack find -v -l lammps

• Use the unique hash symbol to load the desired version of the package (notice only a few of the characters need to be typed if those letters are unique and are not used in the hash of another package)

spack load \dm6