From 198e4dd136c4a5ebb543c7c5c78a58bc1932b909 Mon Sep 17 00:00:00 2001
From: edoapra <edoardo.apra@gmail.com>
Date: Wed, 21 Sep 2022 10:51:57 -0700
Subject: [PATCH 1/2] guess linearity of molecular geometry
 https://github.com/nwchemgit/nwchem/issues/650

---
 src/qmd/qmd_driver.F | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/qmd/qmd_driver.F b/src/qmd/qmd_driver.F
index 3c33a81dfb..ba457b3c5d 100644
--- a/src/qmd/qmd_driver.F
+++ b/src/qmd/qmd_driver.F
@@ -111,8 +111,8 @@ c
       logical task_freq
       external task_freq
 c
-      logical qmd_property
-      external qmd_property
+      logical qmd_property,qmd_linear
+      external qmd_property,qmd_linear
 c
 c     preliminaries
       status_qmd = .true.
@@ -211,6 +211,11 @@ c
 c     set degrees of freedom depending on the type of thermostat
       ndeg = 3*nactive ! initialize ndeg for local thermostats (e.g. langevin)
       if (.not.do_langevin) then  ! for global thermostats
+         if(.not.do_linear) then
+c     check linearity of molecular geometry
+            do_linear=qmd_linear(geom,nat,dbl_mb(k_r))
+               write(6,*) ' do_linear ',do_linear
+         endif
        if (do_linear) then    ! check for linear flag
         ndeg = 3*nactive-5   ! 3N-5 (linear)
        else
@@ -518,3 +523,28 @@ c
 c
       end
 c $Id$
+      logical function qmd_linear(geom,n,xyz)
+      implicit none
+      integer n,geom
+      double precision xyz(3,*)
+c
+      integer i
+      double precision angle
+      logical  geom_calc_angle,geom_cart_coords_get
+      external geom_calc_angle,geom_cart_coords_get
+c      
+      qmd_linear=.true.
+      if(n.eq.2) return
+      if(.not.geom_cart_coords_get(geom, xyz))
+     c        call errquit(' geom_cart_coords fails ',0,0)
+      do i=1,n-2
+         if(.not.geom_calc_angle(
+     1        xyz(1,i),
+     2        xyz(1,i+1),
+     3        xyz(1,i+2),
+     a        angle))
+     c        call errquit(' geom_calc_angle fails ',0,0)
+         if(abs(angle-180d0).gt.1d-5) qmd_linear=.false.
+      enddo
+      return
+      end

From 4b14e31f67e229767a9fcb39457beb9d76985ddb Mon Sep 17 00:00:00 2001
From: edoapra <edoardo.apra@gmail.com>
Date: Wed, 21 Sep 2022 15:37:16 -0700
Subject: [PATCH 2/2] fix for ddab93c26f13d3df6fbcaf78d0698f0dbfce5a63

---
 src/util/util_file_name.F | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/src/util/util_file_name.F b/src/util/util_file_name.F
index e033174586..9b78b539ac 100644
--- a/src/util/util_file_name.F
+++ b/src/util/util_file_name.F
@@ -728,31 +728,35 @@ c
       character*1024 envscr
       integer util_getblnk
       external util_getblnk
+      logical envok
 c
 c     return the name of the scratch/permanent directory for the
 c     specified process
 c
       dir='. '
+      envok=.false.
       if (oscratch) then
          call util_getenv('SCRATCH_DIR',envscr) 
-         if(inp_strlen(envscr).gt.0)  then
-            if(.not.util_file_parse_dir(envscr, dir, ga_nodeid()))
-     I           then
-               if (.not. util_file_parse_dir(scratch_dir, 
-     d              dir, node)) then
-                  dir = '. '    ! Final default is blank
-               endif
+         if(inp_strlen(envscr).gt.0) then
+            envok =
+     U           util_file_parse_dir(envscr, dir, ga_nodeid())
+         endif
+         if(.not.envok)   then
+            if (.not. util_file_parse_dir(scratch_dir, 
+     d           dir, node)) then
+               dir = '. '       ! Final default is blank
             endif
          endif
       else
-         call util_getenv('PERMANENT_DIR',envscr) 
+         call util_getenv('PERMANENT_DIR',envscr)
          if(inp_strlen(envscr).gt.0)  then
-            if(.not.util_file_parse_dir(envscr, dir, ga_nodeid()))
-     I           then
-               if (.not. util_file_parse_dir(permanent_dir, 
-     D              dir, node)) then
-                  dir = '. '    ! Final default is blank
-               endif
+            envok = 
+     U           util_file_parse_dir(envscr, dir, ga_nodeid())
+         endif
+         if(.not.envok) then
+            if (.not. util_file_parse_dir(permanent_dir, 
+     D           dir, node)) then
+               dir = '. '       ! Final default is blank
             endif
          endif
       endif