if(PKG_MSCG)
  find_package(GSL REQUIRED)
  find_package(MSCG QUIET)
  if(MSGC_FOUND)
    set(DOWNLOAD_MSCG_DEFAULT OFF)
  else()
    set(DOWNLOAD_MSCG_DEFAULT ON)
  endif()
  option(DOWNLOAD_MSCG "Download MSCG library instead of using an already installed one)" ${DOWNLOAD_MSCG_DEFAULT})
  if(DOWNLOAD_MSCG)
    include(ExternalProject)
    if(NOT LAPACK_FOUND)
      set(EXTRA_MSCG_OPTS "-DLAPACK_LIBRARIES=${CMAKE_CURRENT_BINARY_DIR}/liblinalg.a")
    endif()
    ExternalProject_Add(mscg_build
      URL https://github.com/uchicago-voth/MSCG-release/archive/1.7.3.1.tar.gz
      URL_MD5 8c45e269ee13f60b303edd7823866a91
      SOURCE_SUBDIR src/CMake
      CMAKE_ARGS ${CMAKE_REQUEST_PIC} ${EXTRA_MSCG_OPTS}
                 -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
                 -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
                 -DCMAKE_Fortran_COMPILER=${CMAKE_Fortran_COMPILER}
                 -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
                 -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
                 -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
                 -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
      BUILD_COMMAND ${CMAKE_COMMAND} --build . --target mscg
      INSTALL_COMMAND ""
      BUILD_BYPRODUCTS <BINARY_DIR>/libmscg.a
      )
    ExternalProject_get_property(mscg_build BINARY_DIR)
    set(MSCG_LIBRARIES ${BINARY_DIR}/libmscg.a)
    ExternalProject_get_property(mscg_build SOURCE_DIR)
    set(MSCG_INCLUDE_DIRS ${SOURCE_DIR}/src)
    add_dependencies(lammps mscg_build)
    if(NOT LAPACK_FOUND)
      file(MAKE_DIRECTORY ${MSCG_INCLUDE_DIRS})
      add_dependencies(mscg_build linalg)
    endif()
  else()
    find_package(MSCG)
    if(NOT MSCG_FOUND)
      message(FATAL_ERROR "MSCG not found, help CMake to find it by setting MSCG_LIBRARY and MSCG_INCLUDE_DIRS, or set DOWNLOAD_MSCG=ON to download it")
    endif()
  endif()
  target_link_libraries(lammps PRIVATE ${MSCG_LIBRARIES} GSL::gsl ${LAPACK_LIBRARIES})
  include_directories(${MSCG_INCLUDE_DIRS})
endif()