diff --git a/CMake/CheckSIMDAlignement.cmake b/CMake/CheckSIMDAlignement.cmake
new file mode 100644
index 0000000000..45af9936b2
--- /dev/null
+++ b/CMake/CheckSIMDAlignement.cmake
@@ -0,0 +1,12 @@
+# Check if AVX512 is activated in the compilation
+# Since cross-compiling is not unusual on HPC systems (Cray),
+# try_compile is robust against 
+try_compile(CXX_COMPILER_HAVE_AVX512_MACRO ${CMAKE_BINARY_DIR}
+      ${PROJECT_CMAKE}/try_compile_sources/checkAVX512.cxx
+      CMAKE_FLAGS "${CMAKE_CXX_FLAGS}")
+
+if (CXX_COMPILER_HAVE_AVX512_MACRO)
+  set(default_alignment 64)
+else()
+  set(default_alignment 32)
+endif()
diff --git a/CMake/ClangCompilers.cmake b/CMake/ClangCompilers.cmake
index 5eb01213cb..12025da282 100644
--- a/CMake/ClangCompilers.cmake
+++ b/CMake/ClangCompilers.cmake
@@ -16,14 +16,14 @@ IF(QMC_OMP)
   SET(ENABLE_OPENMP 1)
   IF(ENABLE_OFFLOAD AND NOT CMAKE_SYSTEM_NAME STREQUAL "CrayLinuxEnvironment")
     SET(OFFLOAD_TARGET "nvptx64-nvidia-cuda" CACHE STRING "Offload target architecture")
-    SET(CLANG_OPENMP_OFFLOAD_FLAGS "-fopenmp-targets=${OFFLOAD_TARGET}")
+    SET(OPENMP_OFFLOAD_COMPILE_OPTIONS "-fopenmp-targets=${OFFLOAD_TARGET}")
 
     IF(DEFINED OFFLOAD_ARCH)
-      SET(CLANG_OPENMP_OFFLOAD_FLAGS "${CLANG_OPENMP_OFFLOAD_FLAGS} -Xopenmp-target=${OFFLOAD_TARGET} -march=${OFFLOAD_ARCH}")
+      SET(OPENMP_OFFLOAD_COMPILE_OPTIONS "${OPENMP_OFFLOAD_COMPILE_OPTIONS} -Xopenmp-target=${OFFLOAD_TARGET} -march=${OFFLOAD_ARCH}")
     ENDIF()
 
     IF(OFFLOAD_TARGET MATCHES "nvptx64")
-      SET(CLANG_OPENMP_OFFLOAD_FLAGS "${CLANG_OPENMP_OFFLOAD_FLAGS} -Wno-unknown-cuda-version")
+      SET(OPENMP_OFFLOAD_COMPILE_OPTIONS "${OPENMP_OFFLOAD_COMPILE_OPTIONS} -Wno-unknown-cuda-version")
     ENDIF()
 
     # Intel clang compiler needs a different flag for the host side OpenMP library when offload is used.
@@ -118,12 +118,6 @@ ELSEIF(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc64" OR CMAKE_SYSTEM_PROCESSOR MATCHES
   ENDIF()
 ENDIF()
 
-# Add OpenMP offload flags
-# This step is intentionally put after the -march parsing for CPUs.
-IF(DEFINED CLANG_OPENMP_OFFLOAD_FLAGS)
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CLANG_OPENMP_OFFLOAD_FLAGS}")
-ENDIF()
-
 # Add static flags if necessary
 IF(QMC_BUILD_STATIC)
     SET(CMAKE_CXX_LINK_FLAGS " -static")
diff --git a/CMake/GNUCompilers.cmake b/CMake/GNUCompilers.cmake
index 00aa17b019..87365d3f8f 100644
--- a/CMake/GNUCompilers.cmake
+++ b/CMake/GNUCompilers.cmake
@@ -10,11 +10,10 @@ SET(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} -std=c99")
 IF(QMC_OMP)
   SET(ENABLE_OPENMP 1)
   SET(CMAKE_C_FLAGS     "${CMAKE_C_FLAGS} -fopenmp")
-  IF(ENABLE_OFFLOAD)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp")
+  IF(ENABLE_OFFLOAD AND NOT CMAKE_SYSTEM_NAME STREQUAL "CrayLinuxEnvironment")
     SET(OFFLOAD_TARGET "nvptx-none" CACHE STRING "Offload target architecture")
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp -foffload=${OFFLOAD_TARGET} -foffload=\"-lm -latomic\"")
-  ELSE()
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp")
+    SET(OPENMP_OFFLOAD_COMPILE_OPTIONS "-foffload=${OFFLOAD_TARGET} -foffload=\"-lm -latomic\"")
   ENDIF()
 ENDIF(QMC_OMP)
 
diff --git a/CMake/IBMCompilers.cmake b/CMake/IBMCompilers.cmake
index 32c66154b9..266c2efbe0 100644
--- a/CMake/IBMCompilers.cmake
+++ b/CMake/IBMCompilers.cmake
@@ -26,10 +26,10 @@ SET( CMAKE_CXX_FLAGS_RELWITHDEBINFO "-g -O3" )
 
 IF(QMC_OMP)
   SET(ENABLE_OPENMP 1)
+  SET(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} -qsmp=omp")
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qsmp=omp")
   IF(ENABLE_OFFLOAD)
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qsmp=omp -qoffload")
-  ELSE(ENABLE_OFFLOAD)
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qsmp=omp")
+    set(OPENMP_OFFLOAD_COMPILE_OPTIONS "-qoffload")
   ENDIF(ENABLE_OFFLOAD)
 ELSE(QMC_OMP)
   SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -qnothreaded")
diff --git a/CMake/PGICompilers.cmake b/CMake/PGICompilers.cmake
index 0ff5336183..93d7ed50b7 100644
--- a/CMake/PGICompilers.cmake
+++ b/CMake/PGICompilers.cmake
@@ -15,7 +15,7 @@ IF(QMC_OMP)
       MESSAGE(FATAL_ERROR "NVIDIA HPC compiler requires -gpu=ccXX option set based on the target GPU architecture! "
                           "Please add -DOFFLOAD_ARCH=ccXX to cmake. For example, cc70 is for Volta.")
     ENDIF()
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mp=gpu -gpu=${OFFLOAD_ARCH}")
+    SET(OPENMP_OFFLOAD_COMPILE_OPTIONS "-mp=gpu -gpu=${OFFLOAD_ARCH}")
   ELSE()
     SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mp=allcores")
   ENDIF()
diff --git a/CMake/try_compile_sources/checkAVX512.cxx b/CMake/try_compile_sources/checkAVX512.cxx
new file mode 100644
index 0000000000..2865e6e0e4
--- /dev/null
+++ b/CMake/try_compile_sources/checkAVX512.cxx
@@ -0,0 +1,8 @@
+// Check if AVX512 is activated by the compiler
+int main(int argc, char **argv)
+{
+#if !defined(__AVX512F__)
+#error "AVX512 not found"
+#endif
+  return 0;
+}
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d20aab97b2..85b66d4f14 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -144,7 +144,6 @@ SET(OHMMS_DIM 3 CACHE STRING "Select physical dimension")
 SET(OHMMS_INDEXTYPE int)
 MESSAGE(STATUS "defining the float point precision")
 SET(OHMMS_PRECISION_FULL double)
-set(QMC_CLINE 32 CACHE STRING "Cache/SIMD alignment in bytes")
 
 IF(QMC_CUDA)
   SET(QMC_MIXED_PRECISION 1 CACHE BOOL "Enable/disable mixed precision")
@@ -429,6 +428,26 @@ IF (BUILD_AFQMC AND NOT APPLE)
   LINK_LIBRARIES("rt")
 ENDIF()
 
+#---------------------------------------------------------------------------
+# Check SIMD alignment for CPU only
+# This is intentionally placed before adding OpenMP offload compile options
+# to avoid contamination from device compilation pass
+#---------------------------------------------------------------------------
+include(CMake/CheckSIMDAlignement.cmake)
+set(QMC_CLINE ${default_alignment} CACHE STRING "Cache/SIMD alignment in bytes")
+math(EXPR alignment_remainder "${QMC_CLINE} % ${default_alignment}")
+if (alignment_remainder)
+  message(FATAL_ERROR "QMC_CLINE must be a multiple of ${default_alignment}. Bad cached value is ${QMC_CLINE}")
+endif()
+message(STATUS "Setting QMC_CLINE to ${QMC_CLINE}")
+
+#---------------------------------------------------------
+# Set up OpenMP offload compile options
+#---------------------------------------------------------
+if (ENABLE_OFFLOAD AND DEFINED OPENMP_OFFLOAD_COMPILE_OPTIONS)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OPENMP_OFFLOAD_COMPILE_OPTIONS}")
+endif()
+
 #-------------------------------------------------------------------
 #  check MPI installation
 #-------------------------------------------------------------------