update mpi.h

Author: mohanchen

CMakeLists.txt

@@ -114,11 +114,13 @@ You can install Git first and reinstall abacus.")
   endif()
 endif()
 
+# Serial version of ABACUS will not use ELPA
 if(NOT ENABLE_MPI)
   set(USE_ELPA OFF)
   set(ENABLE_DEEPKS OFF)
 endif()
 
+# Different exe files of ABACUS
 if(ENABLE_LCAO AND ENABLE_MPI)
   set(ABACUS_BIN_NAME abacus)
 elseif(NOT ENABLE_LCAO AND ENABLE_MPI)
@@ -129,6 +131,7 @@ elseif(ENABLE_LCAO AND NOT ENABLE_MPI)
   set(ABACUS_BIN_NAME abacus_serial)
 endif()
 
+# Use DSP hardware
 if (USE_DSP)
   set(USE_ELPA OFF)
   set(ENABLE_LCAO OFF)

source/module_cell/unitcell.cpp

@@ -17,9 +17,11 @@
 #ifdef __MPI
 #include "mpi.h"
 #endif
+
 #ifdef USE_PAW
 #include "module_cell/module_paw/paw_cell.h"
 #endif
+
 #ifdef __LCAO
 #include "../module_basis/module_ao/ORB_read.h" // to use 'ORB' -- mohan 2021-01-30
 #endif

source/module_io/write_cube.cpp

@@ -4,7 +4,10 @@
 #include<vector>
 #include "module_hamilt_pw/hamilt_pwdft/parallel_grid.h"
 
+#ifdef __MPI
 #include <mpi.h>
+#endif
+
 #include <cstring> 
 
 void ModuleIO::write_vdata_palgrid(

source/module_io/write_istate_info.cpp

@@ -5,7 +5,9 @@
 #include "module_base/global_variable.h"
 #include "module_base/timer.h"
 
+#ifdef __MPI
 #include <mpi.h> // use MPI_Barrier
+#endif
 
 void ModuleIO::write_istate_info(const ModuleBase::matrix &ekb,const ModuleBase::matrix &wg, const K_Vectors& kv)
 {

source/module_io/write_wfc_r.h

@@ -1,8 +1,3 @@
-//======================
-// AUTHOR : Peize Lin
-// DATE :   2021-11-21
-//======================
-
 #ifndef WRITE_WFC_R_H
 #define WRITE_WFC_R_H