From a7d60aa30330f0ac43b2ab0324322ad174097888 Mon Sep 17 00:00:00 2001
From: dceresoli <dceresoli@c92efa57-630b-4861-b058-cf58834340f0>
Date: Sat, 24 Apr 2010 19:03:11 +0000
Subject: [PATCH] Spin polarized B3LYP. (D.C.)

git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@6661 c92efa57-630b-4861-b058-cf58834340f0
---
 Modules/funct.f90 | 20 +++++++++++++++-----
 PW/gradcorr.f90   |  2 +-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/Modules/funct.f90 b/Modules/funct.f90
index 3a52f054a..4f54dda31 100644
--- a/Modules/funct.f90
+++ b/Modules/funct.f90
@@ -868,7 +868,7 @@ subroutine xc_spin (rho, zeta, ex, ec, vxup, vxdw, vcup, vcdw)
   elseif (icorr == 4) then
      call pw_spin (rs, zeta, ec, vcup, vcdw)
   else
-     call errore ('lsda_functional', 'not implemented', icorr)
+     call errore ('lsda_functional (xc_spin)', 'not implemented', icorr)
   endif
   !
   return
@@ -956,7 +956,7 @@ subroutine xc_spin_vec (rho, zeta, length, evx, evc)
   case(4)
      call pw_spin_vec (rs, zeta, evc, length)
   case default
-     call errore ('lsda_functional', 'not implemented', icorr)
+     call errore ('lsda_functional (xc_spin_vec)', 'not implemented', icorr)
   end select
   !
   where (rho.le.small)
@@ -1448,7 +1448,7 @@ subroutine gcc_spin (rho, zeta, grho, sc, v1cup, v1cdw, v2c)
   elseif (igcc == 8) then
      call pbec_spin (rho, zeta, grho, 2, sc, v1cup, v1cdw, v2c)
   else
-     call errore ('lsda_functionals', 'not implemented', igcc)
+     call errore ('lsda_functionals (gcc_spin)', 'not implemented', igcc)
   endif
   !
   return
@@ -1482,10 +1482,20 @@ end subroutine gcc_spin
       V1CB=0.0_DP
       V2CB=0.0_DP
       V2CAB=0.0_DP
-      IF( igcc == 3 ) THEN
+      IF( igcc == 3 .or. igcc == 7) THEN
         RHO=RHOA+RHOB
-        IF(RHO.GT.SMALL)  CALL LSD_GLYP(RHOA,RHOB,GRHOAA,GRHOAB,GRHOBB,SC,&
+        IF(RHO.GT.SMALL) then
+             CALL LSD_GLYP(RHOA,RHOB,GRHOAA,GRHOAB,GRHOBB,SC,&
                   V1CA,V2CA,V1CB,V2CB,V2CAB)
+             if (igcc == 7 .and. exx_started) then
+                SC = 0.81d0*SC
+                V1CA = 0.81d0*V1CA
+                V2CA = 0.81d0*V2CA
+                V1CB = 0.81d0*V1CB
+                V2CB = 0.81d0*V2CB
+                V2CAB = 0.81d0*V2CAB
+             endif
+         endif
       ELSE
         CALL errore( " gcc_spin_more ", " gradiet correction not implemented ", 1 )
       ENDIF
diff --git a/PW/gradcorr.f90 b/PW/gradcorr.f90
index 255a763fd..841324004 100644
--- a/PW/gradcorr.f90
+++ b/PW/gradcorr.f90
@@ -49,7 +49,7 @@ SUBROUTINE gradcorr( rho, rhog, rho_core, rhog_core, etxc, vtxc, v )
   !
   IF ( .NOT. dft_is_gradient() ) RETURN
 
-  igcc_is_lyp = (get_igcc() == 3)
+  igcc_is_lyp = (get_igcc() == 3 .or. get_igcc() == 7)
   !
   etxcgc = 0.D0
   vtxcgc = 0.D0