Some time ago I modified routine at2celldm so that it computed the value of

ibrav even if it was set to 0 and lattice defined by at vectors. It wasn't
such a great idea: may break the phonon code, produces a different output
for scf and non-scf runs, does not account for the unlikely but not impossible
case of rotatted cell. This commit reverts to the previous behaviour, while
still allowing to guess an ibrav if desired.

Modules/dist.f90

@@ -33,6 +33,7 @@ SUBROUTINE run_dist ( exit_status )
   REAL(dp) :: dr(3), dd, dn1, dn2, dn3, scalef, arg
   REAL(dp) :: angolo(nn*(nn-1)/2), drv(3), drn(3,nn), temp, rtemp(3)
   REAL(dp) :: celldm(6), a, b, c, cosab, cosac, cosbc
+  INTEGER, EXTERNAL :: at2ibrav
   !
   exit_status=0
   !
@@ -40,6 +41,7 @@ SUBROUTINE run_dist ( exit_status )
   ! and reprinted along with the lattice vectors, irrespective of
   ! what was provided in output - useful for checking and conversion
   !
+  IF ( ibrav == 0  ) ibrav= at2ibrav (at(1,1), at(1,2), at(1,3))
   CALL at2celldm ( ibrav, alat, at(1,1), at(1,2), at(1,3), celldm )
   CALL celldm2abc ( ibrav, celldm, a,b,c,cosab,cosac,cosbc )
   !

Modules/latgen.f90

@@ -379,30 +379,23 @@ END SUBROUTINE latgen
 SUBROUTINE at2celldm (ibrav,alat,a1,a2,a3,celldm)
   !-----------------------------------------------------------------------
   !
-  !     Returns celldm parameters from lattice vectors
-  !     Tries to guess ibrav if not specified (ibrav=0)
-  !     See latgen for definition of celldm and lattice vectors
+  !     Returns celldm parameters computed from lattice vectors a1,a2,a3 
+  !     If Bravais lattice index ibrav=0, only celldm(1) is set to alat.
+  !     See latgen for definition of celldm and lattice vectors.
+  !     a1, a2, a3, ibrav, alat are not modified
   !
   USE kinds, ONLY: DP
   IMPLICIT NONE
   INTEGER, INTENT(in) :: ibrav
-  real(DP), INTENT(in) :: alat, a1(3), a2(3), a3(3)
-  real(DP), INTENT(out) :: celldm(6)
-  INTEGER :: jbrav
+  REAL(DP), INTENT(in) :: alat, a1(3), a2(3), a3(3)
+  REAL(DP), INTENT(out) :: celldm(6)
   INTEGER, EXTERNAL :: at2ibrav
   !
   celldm = 0.d0
-  jbrav = 0
   !
-  IF ( ibrav == 0 ) THEN
-     jbrav= at2ibrav (a1, a2, a3)
-     IF ( jbrav == 0 ) CALL infomsg('at2celldm', &
-          'could not determine ibrav for lattice vectors')
-  ELSE
-     jbrav = ibrav
-  ENDIF
-
-  SELECT CASE  ( jbrav )
+  SELECT CASE  ( ibrav )
+  CASE (0)
+     celldm(1) = alat
   CASE (1)
      celldm(1) = sqrt( dot_product (a1,a1) )
   CASE (2)
@@ -446,7 +439,7 @@ SUBROUTINE at2celldm (ibrav,alat,a1,a2,a3,celldm)
      celldm(1) = sqrt( dot_product (a1,a1) )
      celldm(2) = sqrt( dot_product(a2(:),a2(:)) ) / celldm(1)
      celldm(3) = sqrt( dot_product(a3(:),a3(:)) ) / celldm(1)
-     IF ( jbrav == 12 ) THEN
+     IF ( ibrav == 12 ) THEN
         celldm(4) = dot_product(a1(:),a2(:)) / celldm(1) / &
              sqrt(dot_product(a2(:),a2(:)))
      ELSE
@@ -468,7 +461,7 @@ SUBROUTINE at2celldm (ibrav,alat,a1,a2,a3,celldm)
      celldm(5) = a3(1)/a1(1)/celldm(3)/2.0_dp
      !celldm(5) = DOT_PRODUCT(a1(:),a3(:)) / &
      !     SQRT(DOT_PRODUCT(a1(:),a1(:)) * DOT_PRODUCT(a3(:),a3(:)))
-  CASE (0,14)
+  CASE (14)
      celldm(1) = sqrt(dot_product(a1(:),a1(:)))
      celldm(2) = sqrt( dot_product(a2(:),a2(:))) / celldm(1)
      celldm(3) = sqrt( dot_product(a3(:),a3(:))) / celldm(1)
@@ -482,8 +475,6 @@ SUBROUTINE at2celldm (ibrav,alat,a1,a2,a3,celldm)
      CALL infomsg('at2celldm', 'wrong ibrav?')
   END SELECT
   !
-  IF ( alat > 0.0_dp) celldm(1) = celldm(1)*alat
-  !
 END SUBROUTINE at2celldm
 !
 INTEGER FUNCTION at2ibrav (a1, a2, a3) RESULT (ibrav)

PP/src/plotband.f90

@@ -641,7 +641,8 @@ PROGRAM plotband
     WRITE (1,'(a)') "set title '"//trim(filename)//"_projected' noenhanced"
     WRITE (1,'(a,f12.6,a)') &
                 &"plot '"//trim(filenamegnu)//&
-                &"' u 1:($2 - ",eref,"):3 w l palette lw 1 notitle, \"
+                &"' u 1:($2 - ",eref,"):3 w l palette lw 1 notitle, "//CHAR(91)
+        ! char(91) = backslash; syntax "something \" confuses the PGI compiler
     WRITE (1,'(f12.6,a)') &
                 &Ef-eref," lt 2 lw 0.5 lc rgb 'grey50' notitle"
     CLOSE (unit=1)

PW/src/pw_restart_new.f90

@@ -1203,7 +1203,7 @@ MODULE pw_restart_new
     !! if ibrav is present, cell parameters were computed by subroutine
     !! "latgen" using ibrav and celldm parameters: recalculate celldm
     !
-    CALL at2celldm (ibrav,1.0_dp,at(:,1),at(:,2),at(:,3),celldm)
+    CALL at2celldm (ibrav,alat,at(:,1),at(:,2),at(:,3),celldm)
     !
     tpiba = tpi/alat
     tpiba2= tpiba**2