diff --git a/include_CLANG.mk b/include_CLANG.mk
index 1383bc0..4a862c8 100644
--- a/include_CLANG.mk
+++ b/include_CLANG.mk
@@ -7,11 +7,11 @@ ANSI_CFLAGS += -std=c99
 ANSI_CFLAGS += -pedantic
 ANSI_CFLAGS += -Wextra
 
-CFLAGS   = -Ofast $(ANSI_CFLAGS) #-g
+CFLAGS   = -Ofast $(ANSI_CFLAGS) -Xpreprocessor -fopenmp #-g
 ASFLAGS  = -masm=intel
 CXXFLAGS = $(CFLAGS)
 FCFLAGS  =
 LFLAGS   =
 DEFINES  = -D_GNU_SOURCE -DALIGNMENT=64
 INCLUDES =
-LIBS     =
+LIBS     = -lomp
diff --git a/src/main.c b/src/main.c
index 96e83a8..b5200f1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -156,6 +156,7 @@ double computeForce(Parameter *param, Atom *atom, Neighbor *neighbor)
         fz[i] = 0.0;
     }
 
+#pragma omp parallel for
     for(int i = 0; i < Nlocal; i++) {
         neighs = &neighbor->neighbors[i * neighbor->maxneighs];
         int numneighs = neighbor->numneigh[i];