added GPU

  option(ENABLE_${PKG} "Build ${PKG} Package" ${ENABLE_ALL})

endforeach()

set(ACCEL_PACKAGES USER-OMP KOKKOS OPT USER-INTEL)

set(ACCEL_PACKAGES USER-OMP KOKKOS OPT USER-INTEL GPU)

foreach(PKG ${ACCEL_PACKAGES})

  option(ENABLE_${PKG} "Build ${PKG} Package" OFF)

endforeach()

    include_directories(${USER-INTEL_SOURCES_DIR})

endif()

if(ENABLE_GPU)

    find_package(CUDA REQUIRED)

    set(GPU_SOURCES_DIR ${LAMMPS_SOURCE_DIR}/GPU)

    set(GPU_SOURCES ${GPU_SOURCES_DIR}/gpu_extra.h)

    set_property(GLOBAL PROPERTY "GPU_SOURCES" "${GPU_SOURCES}")

    # detects styles which have GPU version

    RegisterStylesExt(${GPU_SOURCES_DIR} opt GPU_SOURCES)

    get_property(GPU_SOURCES GLOBAL PROPERTY GPU_SOURCES)

    file(GLOB_RECURSE GPU_LIB_SOURCES ${LAMMPS_LIB_SOURCE_DIR}/gpu/*.cpp

      ${LAMMPS_LIB_SOURCE_DIR}/gpu/*.cu

    cuda_add_library(lammps_gpu ${GPU_LIB_SOURCES})

    list(APPEND LAMMPS_LINK_LIBS lammps_gpu)

    list(APPEND LIB_SOURCES ${GPU_SOURCES})

    include_directories(${GPU_SOURCES_DIR} ${LAMMPS_LIB_SOURCE_DIR}/gpu)

endif()

######################################################

# Generate style headers based on global list of

# styles registered during package selection