Use ELPA_LIB&ELPA_MODULES variables

cmake/tests/test_ELPA.cmake

@@ -2,6 +2,24 @@
 try_compile(FLEUR_USE_ELPA ${CMAKE_BINARY_DIR} ${CMAKE_SOURCE_DIR}/cmake/tests/test_ELPA.f90
 LINK_LIBRARIES ${FLEUR_LIBRARIES})
 
+if (NOT FLEUR_USE_ELPA)
+   if (DEFINED ENV{ELPA_MODULES})
+      set(STORE_FLAGS ${CMAKE_Fortran_FLAGS})
+      set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} -I$ENV{ELPA_MODULES}")
+   endif()
+   if (DEFINED ENV{ELPA_LIB})
+      set(TEST_LIBRARIES "-L${ELPA_LIB};-lelpa_openmp;${FLEUR_LIBRARIES}")
+   endif()
+   try_compile(FLEUR_USE_ELPA ${CMAKE_BINARY_DIR} ${CMAKE_SOURCE_DIR}/cmake/tests/test_ELPA.f90
+LINK_LIBRARIES ${TEST_LIBRARIES})
+   if (FLEUR_USE_ELPA)
+      set(FLEUR_LIBRARIES "${TEST_LIBRARIES}")
+   else()
+      set(CMAKE_Fortran_FLAGS ${STORE_FLAGS})
+   endif()
+endif()
+
+
 message("ELPA Library found:${FLEUR_USE_ELPA}")
 
 #Now check for version of elpa