diff --git a/src/det.irp.f b/src/det.irp.f
index 9e2e11d..c488e12 100644
--- a/src/det.irp.f
+++ b/src/det.irp.f
@@ -434,49 +434,60 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   !DIR$ ASSUME (mod(LDS,$IRP_ALIGN/8) == 0)
   !DIR$ ASSUME (LDS >= $n)
   integer                        :: i,j
-  double precision               :: zl, ui
+  double precision :: zj, zj1, zj2, zj3
   
-  zl = 0.d0
   !DIR$ VECTOR ALIGNED
-  do i=1,$n-1
-    ui = m(i) - S(i,l)
-    u(i) = ui
-    zl = zl + S_inv(i,l)*ui
+  !DIR$ SIMD 
+  do i=1,$n
+    u(i) = m(i) - S(i,l)
   enddo
-  u($n) = m($n) - S($n,l)
-  zl = zl + S_inv($n,l)*u($n)
+
+  zj = 0.d0
+  !DIR$ SIMD REDUCTION(+:zj)
+  do i=1,$n-1,4
+    zj = zj + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1)  &
+            + S_inv(i+2,l)*u(i+2) + S_inv(i+3,l)*u(i+3) 
+  enddo
+  zj = zj + S_inv($n,l)*u($n)
   
   d_inv = 1.d0/d
-  d = d+zl
+  d = d+zj
   lambda = d*d_inv
   if (dabs(lambda) < 1.d-3) then
     d = 0.d0
     return
   endif
   
-  !DIR$ VECTOR ALIGNED
-  z = 0.d0
   !DIR$ VECTOR ALIGNED
   do j=1,$n-1,4
+   zj  = 0.d0
+   zj1 = 0.d0
+   zj2 = 0.d0
+   zj3 = 0.d0
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD REDUCTION(+:zj,zj1,zj2,zj3)
    do i=1,$n-1
-    z(j  ) = z(j  ) + S_inv(i,j  )*u(i)
-    z(j+1) = z(j+1) + S_inv(i,j+1)*u(i)
-    z(j+2) = z(j+2) + S_inv(i,j+2)*u(i)
-    z(j+3) = z(j+3) + S_inv(i,j+3)*u(i)
+    zj  = zj  + S_inv(i,j  )*u(i)
+    zj1 = zj1 + S_inv(i,j+1)*u(i)
+    zj2 = zj2 + S_inv(i,j+2)*u(i)
+    zj3 = zj3 + S_inv(i,j+3)*u(i)
    enddo
-   z(j  ) = z(j  ) + S_inv($n,j  )*u($n)
-   z(j+1) = z(j+1) + S_inv($n,j+1)*u($n)
-   z(j+2) = z(j+2) + S_inv($n,j+2)*u($n)
-   z(j+3) = z(j+3) + S_inv($n,j+3)*u($n)
+   z(j  ) = zj  + S_inv($n,j  )*u($n)
+   z(j+1) = zj1 + S_inv($n,j+1)*u($n)
+   z(j+2) = zj2 + S_inv($n,j+2)*u($n)
+   z(j+3) = zj3 + S_inv($n,j+3)*u($n)
   enddo
 
+  zj  = 0.d0
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD REDUCTION(+:zj)
   do i=1,$n
-   z($n) = z($n) + S_inv(i,$n)*u(i)
+   zj = zj + S_inv(i,$n)*u(i)
   enddo
+  z($n) = zj
 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(d_inv)
   do i=1,$n
     w(i) = S_inv(i,l)*d_inv
     S(i,l) = m(i)
@@ -484,6 +495,7 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   
   do i=1,$n-1,4
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD FIRSTPRIVATE(lambda,z)
    do j=1,$n-1
     S_inv(j,i  ) = S_inv(j,i  )*lambda - w(j)*z(i  )
     S_inv(j,i+1) = S_inv(j,i+1)*lambda - w(j)*z(i+1)
@@ -497,6 +509,7 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   enddo
 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(lambda,z)
   do i=1,$n
    S_inv(i,$n) = S_inv(i,$n)*lambda -w(i)*z($n)
   enddo
@@ -567,61 +580,71 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   !DIR$ ASSUME (LDS >= $n)
   integer                        :: i,j
   
+  double precision :: zj, zj1, zj2, zj3
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD 
   do i=1,$n
     u(i) = m(i) - S(i,l)
   enddo
   
-  z(l) = 0.d0
+  zj = 0.d0
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD REDUCTION(+:zj)
   do i=1,$n-2,4
-    z(l) = z(l) + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1)  &
-                + S_inv(i+2,l)*u(i+2) + S_inv(i+3,l)*u(i+3) 
+    zj = zj + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1)  &
+            + S_inv(i+2,l)*u(i+2) + S_inv(i+3,l)*u(i+3) 
   enddo
   i=$n-1
-  z(l) = z(l) + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1) 
+  zj = zj + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1) 
 
   d_inv = 1.d0/d
-  d = d+z(l)
+  d = d+zj
   lambda = d*d_inv
   if (dabs(lambda) < 1.d-3) then
     d = 0.d0
     return
   endif
   
-  !DIR$ VECTOR ALIGNED
-  z = 0.d0
   !DIR$ VECTOR ALIGNED
   do j=1,$n-2,4
+   zj  = 0.d0
+   zj1 = 0.d0
+   zj2 = 0.d0
+   zj3 = 0.d0
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD REDUCTION(+:zj,zj1,zj2,zj3)
    do i=1,$n-2
-    z(j  ) = z(j  ) + S_inv(i,j  )*u(i)
-    z(j+1) = z(j+1) + S_inv(i,j+1)*u(i)
-    z(j+2) = z(j+2) + S_inv(i,j+2)*u(i)
-    z(j+3) = z(j+3) + S_inv(i,j+3)*u(i)
+    zj  = zj  + S_inv(i,j  )*u(i)
+    zj1 = zj1 + S_inv(i,j+1)*u(i)
+    zj2 = zj2 + S_inv(i,j+2)*u(i)
+    zj3 = zj3 + S_inv(i,j+3)*u(i)
    enddo
-   z(j  ) = z(j  ) + S_inv($n-1,j  )*u($n-1)
+   z(j  ) = zj     + S_inv($n-1,j  )*u($n-1)
    z(j  ) = z(j  ) + S_inv($n,j  )*u($n)
-   z(j+1) = z(j+1) + S_inv($n-1,j+1)*u($n-1)
+   z(j+1) = zj1    + S_inv($n-1,j+1)*u($n-1)
    z(j+1) = z(j+1) + S_inv($n,j+1)*u($n)
-   z(j+2) = z(j+2) + S_inv($n-1,j+2)*u($n-1)
+   z(j+2) = zj2    + S_inv($n-1,j+2)*u($n-1)
    z(j+2) = z(j+2) + S_inv($n,j+2)*u($n)
-   z(j+3) = z(j+3) + S_inv($n-1,j+3)*u($n-1)
+   z(j+3) = zj3    + S_inv($n-1,j+3)*u($n-1)
    z(j+3) = z(j+3) + S_inv($n,j+3)*u($n)
   enddo
 
   j=$n-1
+  zj  = 0.d0
+  zj1 = 0.d0
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD REDUCTION(+:zj,zj1)
   do i=1,$n-2
-   z(j  ) = z(j  ) + S_inv(i,j  )*u(i)
-   z(j+1) = z(j+1) + S_inv(i,j+1)*u(i)
+   zj  = zj  + S_inv(i,j  )*u(i)
+   zj1 = zj1 + S_inv(i,j+1)*u(i)
   enddo
-  z(j  ) = z(j  ) + S_inv($n-1,j  )*u($n-1)
+  z(j  ) = zj     + S_inv($n-1,j  )*u($n-1)
   z(j  ) = z(j  ) + S_inv($n,j  )*u($n)
-  z(j+1) = z(j+1) + S_inv($n-1,j+1)*u($n-1)
+  z(j+1) = zj1    + S_inv($n-1,j+1)*u($n-1)
   z(j+1) = z(j+1) + S_inv($n,j+1)*u($n)
 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(d_inv)
   do i=1,$n
     w(i) = S_inv(i,l)*d_inv
     S(i,l) = m(i)
@@ -629,6 +652,7 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   
   do i=1,$n-2,4
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD FIRSTPRIVATE(lambda,z)
    do j=1,$n-2
     S_inv(j,i  ) = S_inv(j,i  )*lambda -z(i  )*w(j)
     S_inv(j,i+1) = S_inv(j,i+1)*lambda -z(i+1)*w(j)
@@ -647,6 +671,7 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
 
   i=$n-1
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(lambda,z)
   do j=1,$n-2
    S_inv(j,i  ) = S_inv(j,i  )*lambda -z(i  )*w(j)
    S_inv(j,i+1) = S_inv(j,i+1)*lambda -z(i+1)*w(j)
@@ -719,67 +744,75 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   !DIR$ ASSUME (mod(LDS,$IRP_ALIGN/8) == 0)
   !DIR$ ASSUME (LDS >= $n)
   integer                        :: i,j
-  
+
+  double precision :: zj, zj1, zj2, zj3
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD 
   do i=1,$n
     u(i) = m(i) - S(i,l)
   enddo
   
-  z(l) = 0.d0 
+  zj = 0.d0 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD REDUCTION(+:zj)
   do i=1,$n-3,4
-    z(l) = z(l) + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1)  &
-                + S_inv(i+2,l)*u(i+2) + S_inv(i+3,l)*u(i+3) 
+    zj = zj + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1)  &
+            + S_inv(i+2,l)*u(i+2) + S_inv(i+3,l)*u(i+3) 
   enddo
   i=$n-2
-  z(l) = z(l) + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1) + S_inv(i+2,l)*u(i+2)
+  zj = zj + S_inv(i,l)*u(i) + S_inv(i+1,l)*u(i+1) + S_inv(i+2,l)*u(i+2)
 
 
   d_inv = 1.d0/d
-  d = d+z(l)
+  d = d+zj
   lambda = d*d_inv
   if (dabs(lambda) < 1.d-3) then
     d = 0.d0
     return
   endif
   
-  !DIR$ VECTOR ALIGNED
-  z = 0.d0
   !DIR$ VECTOR ALIGNED
   do j=1,$n-3,4
+   zj  = 0.d0
+   zj1 = 0.d0
+   zj2 = 0.d0
+   zj3 = 0.d0
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD REDUCTION(+:zj,zj1,zj2,zj3)
    do i=1,$n-3
-    z(j  ) = z(j  ) + S_inv(i,j  )*u(i)
-    z(j+1) = z(j+1) + S_inv(i,j+1)*u(i)
-    z(j+2) = z(j+2) + S_inv(i,j+2)*u(i)
-    z(j+3) = z(j+3) + S_inv(i,j+3)*u(i)
+    zj  = zj  + S_inv(i,j  )*u(i)
+    zj1 = zj1 + S_inv(i,j+1)*u(i)
+    zj2 = zj2 + S_inv(i,j+2)*u(i)
+    zj3 = zj3 + S_inv(i,j+3)*u(i)
    enddo
-   z(j  ) = z(j  ) + S_inv($n-2,j  )*u($n-2)
+   z(j  ) = zj     + S_inv($n-2,j  )*u($n-2)
    z(j  ) = z(j  ) + S_inv($n-1,j  )*u($n-1)
    z(j  ) = z(j  ) + S_inv($n,j  )*u($n)
-   z(j+1) = z(j+1) + S_inv($n-2,j+1)*u($n-2)
+   z(j+1) = zj1    + S_inv($n-2,j+1)*u($n-2)
    z(j+1) = z(j+1) + S_inv($n-1,j+1)*u($n-1)
    z(j+1) = z(j+1) + S_inv($n,j+1)*u($n)
-   z(j+2) = z(j+2) + S_inv($n-2,j+2)*u($n-2)
+   z(j+2) = zj2    + S_inv($n-2,j+2)*u($n-2)
    z(j+2) = z(j+2) + S_inv($n-1,j+2)*u($n-1)
    z(j+2) = z(j+2) + S_inv($n,j+2)*u($n)
-   z(j+3) = z(j+3) + S_inv($n-2,j+3)*u($n-2)
+   z(j+3) = zj3    + S_inv($n-2,j+3)*u($n-2)
    z(j+3) = z(j+3) + S_inv($n-1,j+3)*u($n-1)
    z(j+3) = z(j+3) + S_inv($n,j+3)*u($n)
   enddo
 
   j=$n-2
-  z(j  ) = S_inv($n,j  )*u($n)
-  z(j+1) = S_inv($n,j+1)*u($n)
-  z(j+2) = S_inv($n,j+2)*u($n)
+  zj  = 0.d0
+  zj1 = 0.d0
+  zj2 = 0.d0
   !DIR$ VECTOR ALIGNED
-  do i=1,$n-1
-   z(j  ) = z(j  ) + S_inv(i,j  )*u(i)
-   z(j+1) = z(j+1) + S_inv(i,j+1)*u(i)
-   z(j+2) = z(j+2) + S_inv(i,j+2)*u(i)
+  !DIR$ SIMD REDUCTION(+:zj,zj1,zj2)
+  do i=1,$n
+   zj  = zj  + S_inv(i,j  )*u(i)
+   zj1 = zj1 + S_inv(i,j+1)*u(i)
+   zj2 = zj2 + S_inv(i,j+2)*u(i)
   enddo
 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(d_inv)
   do i=1,$n
     w(i) = S_inv(i,l)*d_inv
     S(i,l) = m(i)
@@ -787,6 +820,7 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
   
   do i=1,$n-3,4
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD FIRSTPRIVATE(lambda,z)
    do j=1,$n-3
     S_inv(j,i  ) = S_inv(j,i  )*lambda - w(j)*z(i  )
     S_inv(j,i+1) = S_inv(j,i+1)*lambda - w(j)*z(i+1)
@@ -809,6 +843,7 @@ subroutine det_update$n(n,LDS,m,l,S,S_inv,d)
 
   i=$n-2
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(lambda,z)
   do j=1,$n
    S_inv(j,i  ) = S_inv(j,i  )*lambda - w(j)*z(i  )
    S_inv(j,i+1) = S_inv(j,i+1)*lambda - w(j)*z(i+1)
@@ -881,20 +916,23 @@ subroutine det_update_general(n,LDS,m,l,S,S_inv,d)
   !DIR$ ASSUME (n>150)
 
   integer                        :: i,j,n4
+  double precision :: zl
 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD
   do i=1,n
     u(i) = m(i) - S(i,l)
   enddo
   
-  z(l) = 0.d0
+  zl = 0.d0
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD REDUCTION(+:zl)
   do i=1,n
-   z(l) = z(l) + S_inv(i,l)*u(i)
+   zl = zl + S_inv(i,l)*u(i)
   enddo
 
   d_inv = 1.d0/d 
-  d = d+z(l)
+  d = d+zl
   lambda = d*d_inv
   
   if ( dabs(lambda) < 1.d-3 ) then
@@ -902,31 +940,41 @@ subroutine det_update_general(n,LDS,m,l,S,S_inv,d)
     return
   endif
 
+  double precision :: zj, zj1, zj2, zj3
+
   n4 = iand(n,not(3))
   !DIR$ VECTOR ALIGNED
   do j=1,n4,4
-   z(j  ) = 0.d0
-   z(j+1) = 0.d0
-   z(j+2) = 0.d0
-   z(j+3) = 0.d0
+   zj  = 0.d0
+   zj1 = 0.d0
+   zj2 = 0.d0
+   zj3 = 0.d0
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD REDUCTION(+:zj,zj1,zj2,zj3)
    do i=1,n
-    z(j  ) = z(j  ) + S_inv(i,j  )*u(i)
-    z(j+1) = z(j+1) + S_inv(i,j+1)*u(i)
-    z(j+2) = z(j+2) + S_inv(i,j+2)*u(i)
-    z(j+3) = z(j+3) + S_inv(i,j+3)*u(i)
+    zj  = zj  + S_inv(i,j  )*u(i)
+    zj1 = zj1 + S_inv(i,j+1)*u(i)
+    zj2 = zj2 + S_inv(i,j+2)*u(i)
+    zj3 = zj3 + S_inv(i,j+3)*u(i)
    enddo
+   z(j  ) = zj
+   z(j+1) = zj1
+   z(j+2) = zj2
+   z(j+3) = zj3
   enddo
 
   do j=n4+1,n
-   z(j) = 0.d0
+   zj = 0.d0
    !DIR$ VECTOR ALIGNED
+   !DIR$ SIMD REDUCTION(+:zj)
    do i=1,n
-    z(j) = z(j) + S_inv(i,j)*u(i)
+    zj = zj + S_inv(i,j)*u(i)
    enddo
+   z(j  ) = zj
   enddo
 
   !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD FIRSTPRIVATE(d_inv)
   do i=1,n
     w(i) = S_inv(i,l)*d_inv
     S(i,l) = m(i)
@@ -934,7 +982,7 @@ subroutine det_update_general(n,LDS,m,l,S,S_inv,d)
   
   do i=1,n4,4
     !DIR$ VECTOR ALIGNED
-    !DIR$ VECTOR ALWAYS
+    !DIR$ SIMD FIRSTPRIVATE(lambda,z)
     do j=1,n
      S_inv(j,i  ) = S_inv(j,i  )*lambda -z(i  )*w(j)
      S_inv(j,i+1) = S_inv(j,i+1)*lambda -z(i+1)*w(j)
@@ -945,7 +993,7 @@ subroutine det_update_general(n,LDS,m,l,S,S_inv,d)
 
   do i=n4+1,n
     !DIR$ VECTOR ALIGNED
-    !DIR$ VECTOR ALWAYS
+    !DIR$ SIMD FIRSTPRIVATE(lambda,z)
     do j=1,n
       S_inv(j,i) = S_inv(j,i)*lambda -z(i)*w(j)
     enddo
diff --git a/src/mo.irp.f b/src/mo.irp.f
index 12d407a..eb300af 100644
--- a/src/mo.irp.f
+++ b/src/mo.irp.f
@@ -709,7 +709,7 @@ subroutine sparse_full_mv(A,LDA,                                     &
     call MM_PREFETCH (A(j,indices(4)),3)
   IRP_ENDIF
 
-  !DIR$ VECTOR ALIGNED
+  !DIR$ SIMD
   do j=1,LDC
     C1(j) = 0.
     C2(j) = 0.
@@ -755,6 +755,7 @@ subroutine sparse_full_mv(A,LDA,                                     &
     
     do k=0,LDA-1,$IRP_ALIGN/4
       !DIR$ VECTOR ALIGNED
+      !DIR$ SIMD FIRSTPRIVATE(d11,d21,d31,d41)
       do j=1,$IRP_ALIGN/4
         IRP_IF NO_PREFETCH
         IRP_ELSE
@@ -768,6 +769,7 @@ subroutine sparse_full_mv(A,LDA,                                     &
       enddo
     
       !DIR$ VECTOR ALIGNED
+      !DIR$ SIMD FIRSTPRIVATE(d12,d22,d32,d42,d13,d23,d33,d43)
       do j=1,$IRP_ALIGN/4
         C2(j+k) = C2(j+k) + A(j+k,k_vec(1))*d12 + A(j+k,k_vec(2))*d22&
             +   A(j+k,k_vec(3))*d32 + A(j+k,k_vec(4))*d42
@@ -776,6 +778,7 @@ subroutine sparse_full_mv(A,LDA,                                     &
       enddo
     
       !DIR$ VECTOR ALIGNED
+      !DIR$ SIMD FIRSTPRIVATE(d14,d24,d34,d44,d15,d25,d35,d45)
       do j=1,$IRP_ALIGN/4
         C4(j+k) = C4(j+k) + A(j+k,k_vec(1))*d14 + A(j+k,k_vec(2))*d24&
             +   A(j+k,k_vec(3))*d34 + A(j+k,k_vec(4))*d44
@@ -796,6 +799,7 @@ subroutine sparse_full_mv(A,LDA,                                     &
     !DIR$ VECTOR ALIGNED
     do k=0,LDA-1,$IRP_ALIGN/4
       !DIR$ VECTOR ALIGNED
+      !DIR$ SIMD FIRSTPRIVATE(d11,d12,d13,d14,d15)
       do j=1,$IRP_ALIGN/4
         C1(j+k) = C1(j+k) + A(j+k,k_vec(1))*d11
         C2(j+k) = C2(j+k) + A(j+k,k_vec(1))*d12