diff --git a/src/HF/ROHF_fock_matrix.f90 b/src/HF/ROHF_fock_matrix.f90
index 6f7db38..4b35a96 100644
--- a/src/HF/ROHF_fock_matrix.f90
+++ b/src/HF/ROHF_fock_matrix.f90
@@ -1,6 +1,16 @@
 subroutine ROHF_fock_matrix(nBas,nOa,nOb,S,c,Fa,Fb,F)
 
-! Construct the ROHF Fock matrix
+! Construct the ROHF Fock matrix in the AO basis
+! For open shells, the ROHF Fock matrix in the MO basis reads
+!
+!       |   F-K    |  F + K/2  |    F     |
+!       |---------------------------------|
+!       | F + K/2  |     F     |  F - K/2 |
+!       |---------------------------------|
+!       |    F     |  F - K/2  |  F + K   |
+!
+! with F = 1/2 (Fa + Fb) and K = Fb - Fa
+!
 
   implicit none
   include 'parameters.h'
@@ -32,14 +42,14 @@ subroutine ROHF_fock_matrix(nBas,nOa,nOb,S,c,Fa,Fb,F)
 
 ! Roothan canonicalization parameters
 
-  aC = -0.5d0
-  bC = +1.5d0
+  aC = +1.5d0
+  bC = -0.5d0
 
   aO = +0.5d0
   bO = +0.5d0
 
-  aV = +1.5d0
-  bV = -0.5d0
+  aV = -0.5d0
+  bV = +1.5d0
 
 ! Number of closed, open, and virtual orbitals
 
@@ -49,8 +59,8 @@ subroutine ROHF_fock_matrix(nBas,nOa,nOb,S,c,Fa,Fb,F)
 
 ! Block-by-block Fock matrix 
 
-! call AOtoMO_transform(nBas,c,Fa)
-! call AOtoMO_transform(nBas,c,Fb)
+  call AOtoMO_transform(nBas,c,Fa)
+  call AOtoMO_transform(nBas,c,Fb)
 
   F(1:nC,      1:nC      ) =    aC*Fa(1:nC,      1:nC      ) +    bC*Fb(1:nC,      1:nC      )
   F(1:nC,   nC+1:nC+nO   ) =                                         Fb(1:nC,   nC+1:nC+nO   )
@@ -64,8 +74,8 @@ subroutine ROHF_fock_matrix(nBas,nOa,nOb,S,c,Fa,Fb,F)
   F(nO+nC+1:nC+nO+nV,   nC+1:nC+nO   ) =       Fa(nO+nC+1:nC+nO+nV,   nC+1:nC+nO   )
   F(nO+nC+1:nC+nO+nV,nO+nC+1:nC+nO+nV) =    aV*Fa(nO+nC+1:nC+nO+nV,nO+nC+1:nC+nO+nV) +    bV*Fb(nO+nC+1:nC+nO+nV,nO+nC+1:nC+nO+nV)
 
-! call MOtoAO_transform(nBas,S,c,F) 
-! call MOtoAO_transform(nBas,S,c,Fa)
-! call MOtoAO_transform(nBas,S,c,Fb)
+  call MOtoAO_transform(nBas,S,c,F) 
+  call MOtoAO_transform(nBas,S,c,Fa)
+  call MOtoAO_transform(nBas,S,c,Fb)
 
 end subroutine