diff --git a/src/Depend.sh b/src/Depend.sh
index 66e674286ada9c5f74ec13bd9a5fc5cf3916add4..0f78b0bd20ea6a5029deba364e6c3c96be63278b 100644
--- a/src/Depend.sh
+++ b/src/Depend.sh
@@ -12,10 +12,9 @@
 # decisions on (un)installing individual child files are made by
 #   the Install.sh script in the child package
 
-# depend function: args = child-package 0/1
+# depend function: args = child-package
 # checks if child-package is installed, if not just return
-# if parent package is being installed, reinstall the child
-# if parent package is being uninstalled, uninstall the child, reinstall it
+# otherwise update child package according to its dependencies
 
 depend () {
   cd $1
@@ -31,11 +30,11 @@ depend () {
     return
   fi
 
-  echo "  re-installing package $1"
+  echo "  updating package $1"
   if (test -e $1/Install.sh) then
-    cd $1; /bin/sh Install.sh 1; cd ..
+    cd $1; /bin/sh Install.sh 2; cd ..
   else
-    cd $1; /bin/sh ../Install.sh 1; cd ..
+    cd $1; /bin/sh ../Install.sh 2; cd ..
   fi
 }
 
@@ -45,57 +44,69 @@ depend () {
 #   GPU, OPT, USER-CUDA, USER-MISC, USER-OMP
 
 if (test $1 = "ASPHERE") then
-  depend GPU $2
-  depend USER-OMP $2
+  depend GPU
+  depend USER-OMP
 fi
 
 if (test $1 = "CLASS2") then
-  depend GPU $2
-  depend USER-CUDA $2
-  depend USER-OMP $2
+  depend GPU
+  depend USER-CUDA
+  depend USER-OMP
 fi
 
 if (test $1 = "COLLOID") then
-  depend GPU $2
-  depend USER-OMP $2
+  depend GPU
+  depend USER-OMP
+fi
+
+if (test $1 = "DIPOLE") then
+  depend USER-MISC
+  depend USER-OMP
 fi
 
 if (test $1 = "GRANULAR") then
-  depend USER-CUDA $2
-  depend USER-OMP $2
+  depend USER-CUDA
+  depend USER-OMP
 fi
 
 if (test $1 = "KSPACE") then
-  depend GPU $2
-  depend OPT $2
-  depend USER-CUDA $2
-  depend USER-OMP $2
+  depend GPU
+  depend OPT
+  depend USER-CUDA
+  depend USER-OMP
 fi
 
 if (test $1 = "MANYBODY") then
-  depend GPU $2
-  depend OPT $2
-  depend USER-CUDA $2
-  depend USER-MISC $2
-  depend USER-OMP $2
+  depend GPU
+  depend OPT
+  depend USER-CUDA
+  depend USER-MISC
+  depend USER-OMP
+fi
+
+if (test $1 = "MOLECULE") then
+  depend GPU
+  depend USER-CUDA
+  depend USER-MISC
+  depend USER-OMP
 fi
 
 if (test $1 = "PERI") then
-  depend USER-OMP $2
+  depend USER-OMP
 fi
 
 if (test $1 = "RIGID") then
-  depend USER-OMP $2
+  depend USER-OMP
 fi
 
 if (test $1 = "USER-CG-CMM") then
-  depend GPU $2
-  depend USER-CUDA $2
-  depend USER-OMP $2
+  depend GPU
+  depend USER-CUDA
+  depend USER-OMP
 fi
 
 if (test $1 = "USER-MISC") then
-  depend GPU $2
-  depend USER-OMP $2
+  depend GPU
+  depend USER-OMP
 fi
 
diff --git a/src/GPU/Install.sh b/src/GPU/Install.sh
index be89885908e535c5619a4ba9b3792875269b975d..d65574aee3870d6cb0f58c51e2ed53be2157b3ad 100644
--- a/src/GPU/Install.sh
+++ b/src/GPU/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/Install.sh b/src/Install.sh
index 898e828e7f6809b75d897d4c76c5812818ea1989..322631fce9acd30c7eedd0926bd36e43b791eb75 100644
--- a/src/Install.sh
+++ b/src/Install.sh
@@ -19,7 +19,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/KIM/Install.sh b/src/KIM/Install.sh
index 8a32fc50fc40cd21681033991f47b6f554cf8f77..df4670400e8381fda6ee146d14471aa65302fae5 100644
--- a/src/KIM/Install.sh
+++ b/src/KIM/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/MEAM/Install.sh b/src/MEAM/Install.sh
index d56b1daa4fb811ad37f6b210f55f6226b5a68648..acf4c90910cd2208bb688a3370cfd744c2455669 100644
--- a/src/MEAM/Install.sh
+++ b/src/MEAM/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/OPT/Install.sh b/src/OPT/Install.sh
index 5976ed9ee4c338f1cd02a6ec5c73da67e7921dfb..2374072a69760ae10868b37e9a5f691d3dfcb077 100644
--- a/src/OPT/Install.sh
+++ b/src/OPT/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/POEMS/Install.sh b/src/POEMS/Install.sh
index 5179d098c6bea47aca464bf80b3fda499cad67cf..b03792e4f181d670746338d1b9785c9824347146 100644
--- a/src/POEMS/Install.sh
+++ b/src/POEMS/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/Package.sh b/src/Package.sh
index c2ee53586a5f3a8cc75d5fdeccc68e2c5cf731a7..839481c1b57af2fca4a954584f20d69783423be5 100644
--- a/src/Package.sh
+++ b/src/Package.sh
@@ -22,7 +22,7 @@ if (test $2 = "status") then
     for file in *.cpp *.h; do
       if (test ! -e ../$file) then
         echo "  src/$file does not exist"
-      elif (test "`diff --brief $file ../$file`" != "") then
+      elif (! cmp -s $file ../$file) then
         echo "  src/$file and $1/$file are different"
       fi
     done
@@ -36,14 +36,14 @@ if (test $2 = "status") then
 elif (test $2 = "update") then
   echo "Updating src files from $1 package files"
   if (test $installed = 1) then
-    echo "  re-installing package $1"
+    echo "  updating package $1"
     if (test -e Install.sh) then
-      /bin/sh Install.sh 1
+      /bin/sh Install.sh 2
     else
-      /bin/sh ../Install.sh 1
+      /bin/sh ../Install.sh 2
     fi
     cd ..
-    /bin/sh Depend.sh $1 1
+    /bin/sh Depend.sh $1
   else
     echo "  $1 package is not installed"
   fi
@@ -57,7 +57,7 @@ elif (test $2 = "overwrite") then
     for file in *.cpp *.h; do
       if (test ! -e ../$file) then
         continue
-      elif (test "`diff --brief $file ../$file`" != "") then
+      elif (! cmp -s $file ../$file) then
         echo "  overwriting $1/$file"
         cp ../$file .
       fi
@@ -76,7 +76,7 @@ elif (test $2 = "diff") then
     for file in *.cpp *.h; do
       if (test ! -e ../$file) then
         echo "  src/$file does not exist"
-      elif (test "`diff --brief $file ../$file`" != "") then
+      elif (! cmp -s $file ../$file) then
         echo "************************************************"
         echo "diff $1/$file src/$file "
         echo "************************************************"
diff --git a/src/REAX/Install.sh b/src/REAX/Install.sh
index 2c3aaf2302ec344192a017f7c508bc0c21686bc5..af0f1e2436aa0fe0d37e1253daf6f1fc45061ea4 100644
--- a/src/REAX/Install.sh
+++ b/src/REAX/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-ATC/Install.sh b/src/USER-ATC/Install.sh
index 7659bbf95583a9ee1601f1ace61d55d9f91d8dfb..197e94e29df7da9858fd8f1b53106415acdab718 100755
--- a/src/USER-ATC/Install.sh
+++ b/src/USER-ATC/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-AWPMD/Install.sh b/src/USER-AWPMD/Install.sh
index ff6e653a064606bec172690d193f2d05fff4ce35..6fd0718b71374d34e26bf0331f854e5c61bd0102 100644
--- a/src/USER-AWPMD/Install.sh
+++ b/src/USER-AWPMD/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-CG-CMM/Install.sh b/src/USER-CG-CMM/Install.sh
index 65840bf34417c6ae59244c48ce2f0c8936a71c3e..1ae842ab3a12a393b65719f7bb831a2609314112 100644
--- a/src/USER-CG-CMM/Install.sh
+++ b/src/USER-CG-CMM/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-COLVARS/Install.sh b/src/USER-COLVARS/Install.sh
index 2af8737d9f779bf5e6671eb28a6b99beefe0dab1..a50799f47ae8cc9b445872eb560954921eafe687 100755
--- a/src/USER-COLVARS/Install.sh
+++ b/src/USER-COLVARS/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-CUDA/Install.sh b/src/USER-CUDA/Install.sh
index 0c43de7ef2dae2cec4699ef987761bcd16e91aaa..eb84139dcf39c4878a9494affb899d50eb6e4dc4 100755
--- a/src/USER-CUDA/Install.sh
+++ b/src/USER-CUDA/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-MISC/Install.sh b/src/USER-MISC/Install.sh
index 49221113950f8a44bc6c2656c6e639366e9db787..8b2e864787da599513418c534332fc3de406b80c 100644
--- a/src/USER-MISC/Install.sh
+++ b/src/USER-MISC/Install.sh
@@ -15,72 +15,22 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test ! -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
   fi
 }
 
-# list of files with optional dependencies
+# all package files
+# only a few files have dependencies
 
-action angle_cosine_shift.cpp
-action angle_cosine_shift.h
-action angle_cosine_shift_exp.cpp
-action angle_cosine_shift_exp.h
-action angle_dipole.cpp
-action angle_dipole.h
-action angle_fourier.cpp
-action angle_fourier.h
-action angle_fourier_simple.cpp
-action angle_fourier_simple.h
-action angle_quartic.cpp
-action angle_quartic.h
-action bond_harmonic_shift.cpp
-action bond_harmonic_shift.h
-action bond_harmonic_shift_cut.cpp
-action bond_harmonic_shift_cut.h
-action compute_ackland_atom.cpp
-action compute_ackland_atom.h
-action compute_temp_rotate.cpp
-action compute_temp_rotate.h
-action dihedral_cosine_shift_exp.cpp
-action dihedral_cosine_shift_exp.h
-action dihedral_fourier.cpp
-action dihedral_fourier.h
-action dihedral_nharmonic.cpp
-action dihedral_nharmonic.h
-action dihedral_quadratic.cpp
-action dihedral_quadratic.h
-action dihedral_table.cpp
-action dihedral_table.h
-action fix_addtorque.cpp
-action fix_addtorque.h
-action fix_imd.cpp
-action fix_imd.h
-action fix_smd.cpp
-action fix_smd.h
-action improper_cossq.cpp
-action improper_cossq.h
-action improper_fourier.cpp
-action improper_fourier.h
-action improper_ring.cpp
-action improper_ring.h
-action pair_cdeam.cpp pair_eam_alloy.cpp
-action pair_cdeam.h pair_eam_alloy.cpp
-action pair_coul_diel.cpp
-action pair_coul_diel.h
-action pair_dipole_sf.cpp
-action pair_dipole_sf.h
-action pair_edip.cpp
-action pair_edip.h
-action pair_gauss_cut.cpp
-action pair_gauss_cut.h
-action pair_lj_sf.cpp
-action pair_lj_sf.h
-action pair_meam_spline.cpp
-action pair_meam_spline.h
-action pair_meam_sw_spline.cpp
-action pair_meam_sw_spline.h
-action pair_tersoff_table.cpp
-action pair_tersoff_table.h
+for file in *.cpp *.h; do
+  if (test $file = "pair_cdeam.cpp") then
+    action pair_cdeam.cpp pair_eam_alloy.cpp
+  elif (test $file = "pair_cdeam.h") then
+    action pair_cdeam.h pair_eam_alloy.cpp
+  else
+    action $file
+  fi
+done
diff --git a/src/USER-MOLFILE/Install.sh b/src/USER-MOLFILE/Install.sh
index 3493e3a0e306ef42146b5696c581051e0578bca5..537cefda0697b7847ddd397663bfad28096bffe8 100644
--- a/src/USER-MOLFILE/Install.sh
+++ b/src/USER-MOLFILE/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi
diff --git a/src/USER-OMP/Install.sh b/src/USER-OMP/Install.sh
index d948058c2e56f7e44b427afec46b7bbfd868bfa2..9cbbda72a386f9ae8e56bc3d5704b405be8d2293 100644
--- a/src/USER-OMP/Install.sh
+++ b/src/USER-OMP/Install.sh
@@ -1,26 +1,50 @@
 # Install/unInstall package files in LAMMPS
+# mode = 0/1/2 for uninstall/install/update
 
-# step 1: process all *_omp.cpp and *_omp.h files.
-# do not install child files if parent does not exist
+mode=$1
 
-for file in *_omp.cpp *_omp.h ; do
-  ofile=`echo $file | sed  -e 's,\(.*\)_omp\.h,\1.h,' -e 's,\(.*\)_omp\.cpp,\1.cpp,'`
-  if (test $1 = 1) then
-    if (test $file = "thr_omp.h") || (test $file = "thr_omp.cpp") then
-      :  # always install those files.
-    elif (test ! -e ../$ofile) then
-      continue
+# arg1 = file, arg2 = file it depends on
+
+action () {
+  if (test $mode = 0) then
+    rm -f ../$1
+  elif (! cmp -s $1 ../$1) then
+    if (test -z "$2" || test -e ../$2) then
+      cp $1 ..
+      if (test $mode = 2) then
+        echo "  updating src/$1"
+      fi
+    fi
+  elif (test -n "$2") then
+    if (test ! -e ../$2) then
+      rm -f ../$1
     fi
+  fi
+}
+
+# step 1: process all *_omp.cpp and *_omp.h files.
+# do not install child files if parent does not exist
 
-    cp $file ..
+for file in *_omp.cpp; do
+  test $file = thr_omp.cpp && continue
+  dep=${file%_omp.cpp}.cpp
+  action $file $dep
+done
 
-  elif (test $1 = 0) then
-    rm -f ../$file
-  fi
+for file in *_omp.h; do
+  test $file = thr_omp.h && continue
+  dep=${file%_omp.h}.h
+  action $file $dep
 done
 
+action thr_omp.h
+action thr_omp.cpp
+action thr_data.h
+action thr_data.cpp
+
 # step 2: handle cases and tasks not handled in step 1.
-if (test $1 = 1) then
+
+if (test $mode = 1) then
 
   if (test -e ../Makefile.package) then
     sed -i -e 's/[^ \t]*OMP[^ \t]* //' ../Makefile.package
@@ -31,10 +55,7 @@ if (test $1 = 1) then
 
   touch ../accelerator_omp.h
 
-  cp thr_data.h ..
-  cp thr_data.cpp ..
-
-elif (test $1 = 0) then
+elif (test $mode = 0) then
 
   if (test -e ../Makefile.package) then
     sed -i -e 's/[^ \t]*OMP[^ \t]* //' ../Makefile.package
@@ -44,7 +65,4 @@ elif (test $1 = 0) then
 
   touch ../accelerator_omp.h
 
-  rm -f ../thr_data.h
-  rm -f ../thr_data.cpp
-
 fi
diff --git a/src/USER-OMP/Package.sh b/src/USER-OMP/Package.sh
deleted file mode 100644
index e5093da4fd5742bd7e34eeaebbcbed1b20183b6c..0000000000000000000000000000000000000000
--- a/src/USER-OMP/Package.sh
+++ /dev/null
@@ -1,40 +0,0 @@
-# Update package files in LAMMPS
-# Copy package file to src if it doesn't exists or is different.
-# But only copy the file, if a non-OpenMP version exists and
-# remove OpenMP versions that have no matching serial file
-# installed, e.g. after a package has been removed.
-
-for file in *_omp.cpp *_omp.h ; do
-  # these are special cases and handled below
-  if (test $file = "thr_omp.h") || (test $file = "thr_omp.cpp") then
-    continue
-  fi
-  # derive name of non-OpenMP version
-  ofile=`echo $file | sed  -e 's,\(.*\)_omp\.h,\1.h,' -e 's,\(.*\)_omp\.cpp,\1.cpp,'`
-  if (test ! -e ../$ofile) then
-    if (test -e ../$file) then
-      echo "  removing src/$file"
-      rm -f ../$file
-    fi
-  else
-    if (test ! -e ../$file) then
-      echo "  creating src/$file"
-      cp $file ..
-    elif ! cmp -s $file ../$file ; then
-      echo "  updating src/$file"
-      cp $file ..
-    fi
-  fi
-done
-
-# special case for files not covered by the automatic script above
-for file in thr_data.h thr_data.cpp thr_omp.h thr_omp.cpp; do
-  if (test ! -e ../$file) then
-    echo "  creating src/$file"
-    cp $file ..
-  elif ! cmp -s $file ../$file ; then
-    echo "  updating src/$file"
-    cp $file ..
-  fi
-done
-
diff --git a/src/VORONOI/Install.sh b/src/VORONOI/Install.sh
index 65578f2550394ddc088eebddc9a64f22c2604d68..ab310c00805db8863f383d665f469221966e481b 100755
--- a/src/VORONOI/Install.sh
+++ b/src/VORONOI/Install.sh
@@ -15,7 +15,7 @@ action () {
         echo "  updating src/$1"
       fi
     fi
-  elif (test ! -z "$2") then
+  elif (test -n "$2") then
     if (test ! -e ../$2) then
       rm -f ../$1
     fi