diff --git a/Modules/input_parameters.f90 b/Modules/input_parameters.f90
index baf1e62ac..98cfaa034 100644
--- a/Modules/input_parameters.f90
+++ b/Modules/input_parameters.f90
@@ -484,8 +484,10 @@ MODULE input_parameters
           ! OBSOLESCENT: same as vdw_corr='grimme-d2'
           ! other DFT-D parameters ( see Modules/mm_dispersion.f90 )
           ! london_s6 = default global scaling parameter for PBE
+          ! london_c6 = user specified atomic C6 coefficients
         REAL ( DP ) :: london_s6   =   0.75_DP , &
-                       london_rcut = 200.00_DP
+                       london_rcut = 200.00_DP , &
+                       london_c6( nsx ) = -1.0_DP
 
         LOGICAL   :: ts_vdw = .false.
           ! OBSOLESCENT: same as vdw_corr='Tkatchenko-Scheffler'
@@ -563,7 +565,7 @@ MODULE input_parameters
              constrained_magnetization, B_field, fixed_magnetization,         &
              sic, sic_epsilon, force_pairing, sic_alpha,                      &
              tot_charge, tot_magnetization, spline_ps, one_atom_occupations,  &
-             vdw_corr, london, london_s6, london_rcut,                        &
+             vdw_corr, london, london_s6, london_rcut, london_c6,             &
              ts_vdw, ts_vdw_isolated, ts_vdw_econv_thr,                       &
              xdm, xdm_a1, xdm_a2,                                             &
              step_pen, A_pen, sigma_pen, alpha_pen, no_t_rev,                 &
diff --git a/Modules/mm_dispersion.f90 b/Modules/mm_dispersion.f90
index c321547df..1e250a69d 100644
--- a/Modules/mm_dispersion.f90
+++ b/Modules/mm_dispersion.f90
@@ -15,6 +15,7 @@ MODULE london_module
   ! [ S. Grimme, J. Comp. Chem., 27, 1787 (2006) ].
   !
   USE kinds ,           ONLY : DP
+  USE parameters ,      ONLY : nsx
   !
   IMPLICIT NONE
   !
@@ -35,10 +36,11 @@ MODULE london_module
   ! r     ( 3 , mxr )     : ordered distance vectors
   ! dist2 ( mxr )         : ordered distances
   !
-  REAL ( DP ) , PUBLIC :: scal6=0._dp , lon_rcut=0._dp
+  REAL ( DP ) , PUBLIC :: scal6=0._dp , lon_rcut=0._dp , in_C6 ( nsx )
   !
   ! scal6    : global scaling factor
   ! lon_rcut : public cut-off radius
+  ! in_C6 ( ntyp ) : input (user) specified atomic C6 coefficients
   !
   INTEGER , PRIVATE :: mxr
   !
@@ -204,7 +206,11 @@ MODULE london_module
            !
            i = atomic_number ( atom_label ( ilab ) )
            IF ( i > 0 .AND. i < 87 ) THEN
-              C6_i  ( ilab )  = vdw_coeffs(1,i)
+              IF ( in_C6 (ilab) > 0.0_DP ) THEN
+                 C6_i  ( ilab )  = in_C6 (ilab)
+              ELSE
+                 C6_i  ( ilab )  = vdw_coeffs(1,i)
+              END IF
               R_vdw ( ilab )  = vdw_coeffs(2,i)
            ELSE
              CALL errore ( ' init_london ' ,&
diff --git a/Modules/read_namelists.f90 b/Modules/read_namelists.f90
index f0a34c560..c29286503 100644
--- a/Modules/read_namelists.f90
+++ b/Modules/read_namelists.f90
@@ -245,6 +245,7 @@ MODULE read_namelists_module
        london      = .false.
        london_s6   = 0.75_DP
        london_rcut = 200.00_DP
+       london_c6   = -1.0_DP
        ts_vdw          = .FALSE.
        ts_vdw_isolated = .FALSE.
        ts_vdw_econv_thr = 1.E-6_DP
@@ -803,6 +804,7 @@ MODULE read_namelists_module
        CALL mp_bcast( london,                    ionode_id, intra_image_comm )
        CALL mp_bcast( london_s6,                 ionode_id, intra_image_comm )
        CALL mp_bcast( london_rcut,               ionode_id, intra_image_comm )
+       CALL mp_bcast( london_c6,                 ionode_id, intra_image_comm )
        CALL mp_bcast( xdm,                       ionode_id, intra_image_comm )
        CALL mp_bcast( xdm_a1,                    ionode_id, intra_image_comm )
        CALL mp_bcast( xdm_a2,                    ionode_id, intra_image_comm )