diff --git a/src/diagnose.F90 b/src/diagnose.F90
index ed872ad1a74e18b35b26f038ac045dc4f7df5d7d..b3e53fc2c998eb7e6aaa9321b8432494ee331501 100644
--- a/src/diagnose.F90
+++ b/src/diagnose.F90
@@ -157,7 +157,7 @@ SUBROUTINE diagnose_full(kstep)
     CALL putarrnd(fidres, "/data/metric/hatR",          hatR(izs:ize,0:1), (/1, 1, 1/))
     CALL putarrnd(fidres, "/data/metric/hatZ",          hatZ(izs:ize,0:1), (/1, 1, 1/))
     CALL putarrnd(fidres, "/data/metric/hatB",          hatB(izs:ize,0:1), (/1, 1, 1/))
-    CALL putarrnd(fidres, "/data/metric/hatB_NL",    hatB_NL(izs:ize,0:1), (/1, 1, 1/))
+    CALL putarrnd(fidres, "/data/metric/Gamma_NL",    Gamma_NL(izs:ize,0:1), (/1, 1, 1/))
     CALL putarrnd(fidres, "/data/metric/dBdx",      dBdx(izs:ize,0:1), (/1, 1, 1/))
     CALL putarrnd(fidres, "/data/metric/dBdy",      dBdy(izs:ize,0:1), (/1, 1, 1/))
     CALL putarrnd(fidres, "/data/metric/dBdz",      dBdz(izs:ize,0:1), (/1, 1, 1/))
diff --git a/src/geometry_mod.F90 b/src/geometry_mod.F90
index 4c90e1e520794f3e5278eeaab0703fedace44824..7b41ffbf020b36e18da66886c1e70f295dbd4b7a 100644
--- a/src/geometry_mod.F90
+++ b/src/geometry_mod.F90
@@ -57,13 +57,17 @@ implicit none
   ! derivatives of magnetic field strength
   REAL(dp),    PUBLIC, DIMENSION(:,:), ALLOCATABLE :: dBdx, dBdy, dBdz
   ! Relative magnetic field strength
-  REAL(dp),    PUBLIC, DIMENSION(:,:), ALLOCATABLE :: hatB, hatB_NL
+  REAL(dp),    PUBLIC, DIMENSION(:,:), ALLOCATABLE :: hatB
   ! Relative strength of major radius
   REAL(dp),    PUBLIC, DIMENSION(:,:), ALLOCATABLE :: hatR, hatZ
   ! Some geometrical coefficients
   REAL(dp),    PUBLIC, DIMENSION(:,:) , ALLOCATABLE :: gradz_coeff  ! 1 / [ J_{xyz} \hat{B} ]
   ! Array to map the index of mode (kx,ky,-pi) to (kx+2pi*s*ky,ky,pi) for sheared periodic boundary condition
   INTEGER,     PUBLIC, DIMENSION(:,:), ALLOCATABLE :: ikx_zBC_L, ikx_zBC_R
+  ! Geometric factor in front of the nonlinear term (gxx gyy - gxy^2)
+  REAL(dp),    PUBLIC, DIMENSION(:,:), ALLOCATABLE :: Gamma_NL
+  ! Geometric factor in front of the parallel phi derivative (not implemented)
+  ! REAL(dp),    PUBLIC, DIMENSION(:,:), ALLOCATABLE :: Gamma_phipar
   ! pb_phase, for parallel boundary phase, contains the factor that occurs when taking into account
   !   that q0 is defined in the middle of the fluxtube whereas the radial position spans in [0,Lx)
   !   This shift introduces a (-1)^(Nexc*iky) phase change that is included in GENE
@@ -166,9 +170,9 @@ CONTAINS
         gradz_coeff(iz,eo) = 1._dp /(jacobian(iz,eo)*hatB(iz,eo))
 
         ! Nonlinear term prefactor
-        ! (according to my derivations, there should be a metric dependent factor in front of the Poisson bracket)
-        hatB_NL(iz,eo) = (gxx(iz,eo)*gyy(iz,eo) - gxy(iz,eo)**2)
-
+        Gamma_NL(iz,eo)    = 1._dp ! = G1
+        ! Geometric factor in front to the maxwellian dzphi term (not implemented)
+        ! Gamma_phipar(iz,eo) = -G2/G1
       ENDDO
     ENDDO
 
@@ -271,7 +275,7 @@ CONTAINS
 
     ! Relative strengh of modulus of B
       hatB   (iz,eo) = 1._dp
-      hatB_NL(iz,eo) = 1._dp
+      Gamma_NL(iz,eo) = 1._dp
 
     ! Derivative of the magnetic field strenght
       dBdx(iz,eo) = -hatB(iz,eo) ! LB = 1
@@ -472,7 +476,8 @@ END SUBROUTINE set_ikx_zBC_map
        CALL allocate_array(     dBdy,izgs,izge, 0,1)
        CALL allocate_array(     dBdz,izgs,izge, 0,1)
        CALL allocate_array(       hatB,izgs,izge, 0,1)
-       CALL allocate_array(    hatB_NL,izgs,izge, 0,1)
+       CALL allocate_array(    Gamma_NL,izgs,izge, 0,1)
+       ! CALL allocate_array(Gamma_phipar,izgs,izge, 0,1) (not implemented)
        CALL allocate_array(       hatR,izgs,izge, 0,1)
        CALL allocate_array(       hatZ,izgs,izge, 0,1)
        CALL allocate_array(         Rc,izgs,izge, 0,1)