diff --git a/lib/Install.py b/lib/Install.py
index 416a2319c..d30cbffcf 100644
--- a/lib/Install.py
+++ b/lib/Install.py
@@ -1,100 +1,101 @@
 #!/usr/bin/env python
 
 # install.py tool to do a generic build of a library
 # soft linked to by many of the lib/Install.py files
 # used to automate the steps described in the corresponding lib/README
 
 from __future__ import print_function
 import sys,os,subprocess
 
 # help message
 
 help = """
 Syntax from src dir: make lib-libname args="-m machine -e suffix"
 Syntax from lib dir: python Install.py -m machine -e suffix
 
 libname = name of lib dir (e.g. atc, h5md, meam, poems, etc)
 specify -m and optionally -e, order does not matter
 
   -m = peform a clean followed by "make -f Makefile.machine"
        machine = suffix of a lib/Makefile.* file
   -e = set EXTRAMAKE variable in Makefile.machine to Makefile.lammps.suffix
        does not alter existing Makefile.machine
 
 Examples:
 
-make lib-poems args="-m g++"    # build COLVARS lib with GNU g++ compiler
-make lib-meam args="-m ifort"   # build MEAM lib with Intel ifort compiler
+make lib-poems args="-m serial" # build POEMS lib with same settings as in the serial Makefile in src
+make lib-colvars args="-m mpi"  # build USER-COLVARS lib with same settings as in the mpi Makefile in src
+make lib-meam args="-m ifort"   # build MEAM lib with custom Makefile.ifort (using Intel Fortran)
 """
 
 # print error message or help
 
 def error(str=None):
   if not str: print(help)
   else: print("ERROR",str)
   sys.exit()
 
 # parse args
 
 args = sys.argv[1:]
 nargs = len(args)
 if nargs == 0: error()
 
 machine = None
 extraflag = 0
 
 iarg = 0
 while iarg < nargs:
   if args[iarg] == "-m":
     if iarg+2 > nargs: error()
     machine = args[iarg+1]
     iarg += 2
   elif args[iarg] == "-e":
     if iarg+2 > nargs: error()
     extraflag = 1
     suffix = args[iarg+1]
     iarg += 2
   else: error()
 
 # set lib from working dir
 
 cwd = os.getcwd()
 lib = os.path.basename(cwd)
 
 # create Makefile.auto as copy of Makefile.machine
 # reset EXTRAMAKE if requested
 
 if not os.path.exists("Makefile.%s" % machine):
   error("lib/%s/Makefile.%s does not exist" % (lib,machine))
 
 lines = open("Makefile.%s" % machine,'r').readlines()
 fp = open("Makefile.auto",'w')
 
 has_extramake = False
 for line in lines:
   words = line.split()
   if len(words) == 3 and words[0] == "EXTRAMAKE" and words[1] == '=':
     has_extramake = True
     if extraflag:
       line = line.replace(words[2],"Makefile.lammps.%s" % suffix)
   fp.write(line)
 
 fp.close()
 
 # make the library via Makefile.auto optionally with parallel make
 
 try:
   import multiprocessing
   n_cpus = multiprocessing.cpu_count()
 except:
   n_cpus = 1
 
 print("Building lib%s.a ..." % lib)
 cmd = "make -f Makefile.auto clean; make -f Makefile.auto -j%d" % n_cpus
 txt = subprocess.check_output(cmd,shell=True,stderr=subprocess.STDOUT)
 print(txt.decode('UTF-8'))
 
 if os.path.exists("lib%s.a" % lib): print("Build was successful")
 else: error("Build of lib/%s/lib%s.a was NOT successful" % (lib,lib))
 if has_extramake and not os.path.exists("Makefile.lammps"):
   print("lib/%s/Makefile.lammps was NOT created" % lib)
diff --git a/lib/kim/Install.py b/lib/kim/Install.py
index f7ddcfda9..06479d2d4 100644
--- a/lib/kim/Install.py
+++ b/lib/kim/Install.py
@@ -1,276 +1,280 @@
 #!/usr/bin/env python
 
-# install.py tool to setup the kim-api library
+# install.py tool to download, compile, and setup the kim-api library
 # used to automate the steps described in the README file in this dir
+
 from __future__ import print_function
 import sys,os,re,subprocess
 
-# transparently use either urllib or an external tool
-try:
-  import ssl
-  try: from urllib.request import urlretrieve as geturl
-  except: from urllib import urlretrieve as geturl
-except:
-  def geturl(url,fname):
-    cmd = 'curl -L -o "%s" %s' % (fname,url)
-    txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
-    return txt
-
 help = """
-Syntax from src dir: make lib-kim args="-v version  -a kim-name"
-Syntax from lib dir: python Install.py -v version  -a kim-name
+Syntax from src dir: make lib-kim args="-b -v version  -a kim-name"
+                 or: make lib-kim args="-b -a everything"
+                 or: make lib-kim args="-n -a kim-name"
+                 or: make lib-kim args="-p /usr/local/open-kim -a kim-name"
+Syntax from lib dir: python Install.py -b -v version  -a kim-name
+                 or: python Install.py -b -a everything
+                 or: python Install.py -n -a kim-name
+                 or: python Install.py -p /usr/local/open-kim -a kim-name
 
 specify one or more options, order does not matter
 
   -v = version of KIM API library to use
        default = kim-api-v1.8.2 (current as of June 2017)
-  -b = download and build base KIM API library with example Models (default)
+  -b = download and build base KIM API library with example Models
        this will delete any previous installation in the current folder
-  -n = do NOT download and build base KIM API library. Use an existing installation
+  -n = do NOT download and build base KIM API library.
+       Use an existing installation 
   -p = specify location of KIM API installation (implies -n)
   -a = add single KIM model or model driver with kim-name
        to existing KIM API lib (see example below).
        If kim-name = everything, then rebuild KIM API library with
-       all available OpenKIM Models (this implies -b).
+       *all* available OpenKIM Models (make take a long time).
   -vv = be more verbose about what is happening while the script runs
 
 Examples:
 
-make lib-kim           # install KIM API lib with only example models
+make lib-kim args="-b" # install KIM API lib with only example models
 make lib-kim args="-a Glue_Ercolessi_Adams_Al__MO_324507536345_001"  # Ditto plus one model
-make lib-kim args="-a everything"   # install KIM API lib with all models
+make lib-kim args="-b -a everything"   # install KIM API lib with all models
 make lib-kim args="-n -a EAM_Dynamo_Ackland_W__MO_141627196590_002"   # only add one model or model driver
 
 See the list of KIM model drivers here:
 https://openkim.org/kim-items/model-drivers/alphabetical
 
 See the list of all KIM models here:
 https://openkim.org/kim-items/models/by-model-drivers
 
 See the list of example KIM models included by default here:
 https://openkim.org/kim-api
 in the "What is in the KIM API source package?" section
 """
 
-def error():
-  print(help)
+def error(str=None):
+  if not str: print(help)
+  else: print("ERROR",str)
   sys.exit()
 
 # expand to full path name
 # process leading '~' or relative path
 
 def fullpath(path):
   return os.path.abspath(os.path.expanduser(path))
 
+def geturl(url,fname):
+  cmd = 'curl -L -o "%s" %s' % (fname,url)
+  txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
+  return txt
+
 # parse args
 
 args = sys.argv[1:]
 nargs = len(args)
+if nargs == 0: error()
 
 thisdir = os.environ['PWD']
 version = "kim-api-v1.8.2"
 
-buildflag = True
+buildflag = False
 everythingflag = False
 addflag = False
 verboseflag = False
 pathflag = False
 
 iarg = 0
 while iarg < len(args):
   if args[iarg] == "-v":
     if iarg+2 > len(args): error()
     version = args[iarg+1]
     iarg += 2
   elif args[iarg] == "-b":
     buildflag = True
     iarg += 1
   elif args[iarg] == "-n":
     buildflag = False
     iarg += 1
   elif args[iarg] == "-p":
     if iarg+2 > len(args): error()
     kimdir = fullpath(args[iarg+1])
     pathflag = True
     buildflag = False
     iarg += 2
   elif args[iarg] == "-a":
     addflag = True
     if iarg+2 > len(args): error()
     addmodelname = args[iarg+1]
     if addmodelname == "everything":
       buildflag = True
       everythingflag = True
       addflag = False
     iarg += 2
   elif args[iarg] == "-vv":
     verboseflag = True
     iarg += 1
   else: error()
 
 thisdir = os.path.abspath(thisdir)
 url = "https://s3.openkim.org/kim-api/%s.tgz" % version
 
 # set KIM API directory
 
 if pathflag:
   if not os.path.isdir(kimdir):
     print("\nkim-api is not installed at %s" % kimdir)
     error()
 
   # configure LAMMPS to use existing kim-api installation
   with open("%s/Makefile.KIM_DIR" % thisdir, 'w') as mkfile:
     mkfile.write("KIM_INSTALL_DIR=%s\n\n" % kimdir)
     mkfile.write(".DUMMY: print_dir\n\n")
     mkfile.write("print_dir:\n")
     mkfile.write("	@printf $(KIM_INSTALL_DIR)\n")
 
   with open("%s/Makefile.KIM_Config" % thisdir, 'w') as cfgfile:
     cfgfile.write("include %s/lib/kim-api/Makefile.KIM_Config" % kimdir)
 
   print("Created %s/Makefile.KIM_DIR\n  using %s" % (thisdir,kimdir))
 else:
   kimdir = os.path.join(os.path.abspath(thisdir), "installed-" + version)
 
 # download KIM tarball, unpack, build KIM
 if buildflag:
 
   # check to see if an installed kim-api already exists and wipe it out.
 
   if os.path.isdir(kimdir):
     print("kim-api is already installed at %s.\nRemoving it for re-install" % kimdir)
     cmd = 'rm -rf "%s"' % kimdir
     subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
 
   # configure LAMMPS to use kim-api to be installed
 
   with open("%s/Makefile.KIM_DIR" % thisdir, 'w') as mkfile:
     mkfile.write("KIM_INSTALL_DIR=%s\n\n" % kimdir)
     mkfile.write(".DUMMY: print_dir\n\n")
     mkfile.write("print_dir:\n")
     mkfile.write("	@printf $(KIM_INSTALL_DIR)\n")
 
   with open("%s/Makefile.KIM_Config" % thisdir, 'w') as cfgfile:
     cfgfile.write("include %s/lib/kim-api/Makefile.KIM_Config" % kimdir)
 
   print("Created %s/Makefile.KIM_DIR\n  using %s" % (thisdir,kimdir))
 
   # download entire kim-api tarball
 
   print("Downloading kim-api tarball ...")
   geturl(url,"%s/%s.tgz" % (thisdir,version))
   print("Unpacking kim-api tarball ...")
   cmd = 'cd "%s"; rm -rf "%s"; tar -xzvf %s.tgz' % (thisdir,version,version)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
 
   # configure kim-api
 
   print("Configuring kim-api ...")
   cmd = 'cd "%s/%s"; ./configure --prefix="%s"' % (thisdir,version,kimdir)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
 
   # build kim-api
 
   print("Configuring example Models")
   cmd = 'cd "%s/%s"; make add-examples' % (thisdir,version)
   txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   if verboseflag: print (txt.decode("UTF-8"))
 
   if everythingflag:
     print("Configuring all OpenKIM models, this will take a while ...")
     cmd = 'cd "%s/%s"; make add-OpenKIM' % (thisdir,version)
     txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
     if verboseflag: print(txt.decode("UTF-8"))
 
   print("Building kim-api ...")
   cmd = 'cd "%s/%s"; make' % (thisdir,version)
   txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   if verboseflag: print(txt.decode("UTF-8"))
 
   # install kim-api
 
   print("Installing kim-api ...")
   cmd = 'cd "%s/%s"; make install' % (thisdir,version)
   txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   if verboseflag: print(txt.decode("UTF-8"))
 
   cmd = 'cd "%s/%s"; make install-set-default-to-v1' %(thisdir,version)
   txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   if verboseflag: print(txt.decode("UTF-8"))
 
   # remove source files
 
   print("Removing kim-api source and build files ...")
   cmd = 'cd "%s"; rm -rf %s; rm -rf %s.tgz' % (thisdir,version,version)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
 
 # add a single model (and possibly its driver) to existing KIM installation
 
 if addflag:
 
   if not os.path.isdir(kimdir):
     print("\nkim-api is not installed")
     error()
 
   # download single model
 
   print("Downloading tarball for %s..." % addmodelname)
   url = "https://openkim.org/download/%s.tgz" % addmodelname
   geturl(url,"%s/%s.tgz" % (thisdir,addmodelname))
 
   print("Unpacking item tarball ...")
   cmd = 'cd "%s"; tar -xzvf %s.tgz' % (thisdir,addmodelname)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
 
   print("Building item ...")
   cmd = 'cd "%s/%s"; make; make install' %(thisdir,addmodelname)
   try:
     txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   except subprocess.CalledProcessError as e:
 
     # Error: but first, check to see if it needs a driver
     firstRunOutput = e.output.decode("UTF-8")
 
     cmd = 'cd "%s/%s"; make kim-item-type' % (thisdir,addmodelname)
     txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
     txt = txt.decode("UTF-8")
     if txt == "ParameterizedModel":
 
       # Get and install driver
 
       cmd = 'cd "%s/%s"; make model-driver-name' % (thisdir,addmodelname)
       txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
       adddrivername = txt.decode("UTF-8").strip()
       print("First installing model driver: %s..." % adddrivername)
       cmd = 'cd "%s"; python Install.py -n -a %s' % (thisdir,adddrivername)
       try:
         txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
       except subprocess.CalledProcessError as e:
         print(e.output)
         sys.exit()
 
       if verboseflag: print(txt.decode("UTF-8"))
 
       # now install the model that needed the driver
 
       print("Now installing model : %s" % addmodelname)
       cmd = 'cd "%s"; python Install.py -n -a %s' % (thisdir,addmodelname)
       try:
         txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
       except subprocess.CalledProcessError as e:
         print(e.output)
         sys.exit()
       print(txt.decode("UTF-8"))
       sys.exit()
     else:
       print(firstRunOutput)
       print("Error, unable to build and install OpenKIM item: %s" \
             % addmodelname)
       sys.exit()
 
   # success the first time
 
   if verboseflag: print(txt.decode("UTF-8"))
   print("Removing kim item source and build files ...")
   cmd = 'cd "%s"; rm -rf %s; rm -rf %s.tgz' %(thisdir,addmodelname,addmodelname)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
diff --git a/lib/mscg/Install.py b/lib/mscg/Install.py
index 70d2eda24..e4e5ec561 100644
--- a/lib/mscg/Install.py
+++ b/lib/mscg/Install.py
@@ -1,149 +1,151 @@
 #!/usr/bin/env python
 
 # Install.py tool to download, unpack, build, and link to the MS-CG library
 # used to automate the steps described in the README file in this dir
 
 from __future__ import print_function
 import sys,os,re,subprocess
 
-try:
-  import ssl
-  try: from urllib.request import urlretrieve as geturl
-  except: from urllib import urlretrieve as geturl
-except:
-  def geturl(url,fname):
-    cmd = 'curl -L -o "%s" %s' % (fname,url)
-    txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
-    return txt
-
 # help message
 
 help = """
 Syntax from src dir: make lib-mscg args="-p [path] -m [suffix]"
+                 or: make lib-mscg args="-b -m [suffix]"
 Syntax from lib dir: python Install.py -p [path]  -m [suffix]
+Syntax from lib dir: python Install.py -b -m [suffix]
 
 specify one or more options, order does not matter
 
-  -b = download and build MS-CG library (default)
+  -b = download and build MS-CG library
   -p = specify folder of existing MS-CG installation
   -m = machine suffix specifies which src/Make/Makefile.suffix to use
        default suffix = g++_simple
 
 Example:
 
-make lib-mscg args="-b "   # download/build in lib/mscg/MSCG-release-master
+make lib-mscg args="-b -m serial " # download/build in lib/mscg/MSCG-release-master with settings compatible with "make serial"
+make lib-mscg args="-b -m mpi " # download/build in lib/mscg/MSCG-release-master with settings compatible with "make mpi"
+make lib-mscg args="-p /usr/local/mscg-release " # use existing MS-CG installation in /usr/local/mscg-release
 """
 
 # settings
 
 url = "http://github.com/uchicago-voth/MSCG-release/archive/master.tar.gz"
 tarfile = "MS-CG-master.tar.gz"
 tardir = "MSCG-release-master"
 
 # print error message or help
 
 def error(str=None):
   if not str: print(help)
   else: print("ERROR",str)
   sys.exit()
 
 # expand to full path name
 # process leading '~' or relative path
 
 def fullpath(path):
   return os.path.abspath(os.path.expanduser(path))
 
+def geturl(url,fname):
+  cmd = 'curl -L -o "%s" %s' % (fname,url)
+  txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
+  return txt
+
 # parse args
 
 args = sys.argv[1:]
 nargs = len(args)
+if nargs == 0: error()
 
 homepath = "."
 homedir = tardir
 
-buildflag = True
+buildflag = False
 pathflag = False
 linkflag = True
 msuffix = "g++_simple"
 
 iarg = 0
 while iarg < nargs:
   if args[iarg] == "-p":
     if iarg+2 > nargs: error()
     mscgpath = fullpath(args[iarg+1])
     pathflag = True
-    buildflag = False
     iarg += 2
   elif args[iarg] == "-m":
     if iarg+2 > nargs: error()
     msuffix = args[iarg+1]
     iarg += 2
   elif args[iarg] == "-b":
     buildflag = True
     iarg += 1
   else: error()
 
 homepath = fullpath(homepath)
 homedir = "%s/%s" % (homepath,homedir)
 
 if (pathflag):
     if not os.path.isdir(mscgpath): error("MS-CG path does not exist")
     homedir = mscgpath
 
 if (buildflag and pathflag):
     error("Cannot use -b and -p flag at the same time")
 
+if (not buildflag and not pathflag):
+    error("Have to use either -b or -p flag")
+
 # download and unpack MS-CG tarfile
 
 if buildflag:
   print("Downloading MS-CG ...")
   geturl(url,"%s/%s" % (homepath,tarfile))
 
   print("Unpacking MS-CG tarfile ...")
   if os.path.exists("%s/%s" % (homepath,tardir)):
     cmd = 'rm -rf "%s/%s"' % (homepath,tardir)
     subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   cmd = 'cd "%s"; tar -xzvf %s' % (homepath,tarfile)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   os.remove("%s/%s" % (homepath,tarfile))
   if os.path.basename(homedir) != tardir:
     if os.path.exists(homedir):
       cmd = 'rm -rf "%s"' % homedir
       subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
     os.rename("%s/%s" % (homepath,tardir),homedir)
 
 # build MS-CG
 
 if buildflag:
   print("Building MS-CG ...")
   if os.path.exists("%s/src/Make/Makefile.%s" % (homedir,msuffix)):
     cmd = 'cd "%s/src"; cp Make/Makefile.%s .; make -f Makefile.%s' % \
         (homedir,msuffix,msuffix)
   elif os.path.exists("Makefile.%s" % msuffix):
     cmd = 'cd "%s/src"; cp ../../Makefile.%s .; make -f Makefile.%s' % \
         (homedir,msuffix,msuffix)
   else:
     error("Cannot find Makefile.%s" % msuffix)
   txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   print(txt.decode('UTF-8'))
   if not os.path.exists("Makefile.lammps"):
     print("Creating Makefile.lammps")
     if os.path.exists("Makefile.lammps.%s" % msuffix):
       cmd = 'cp Makefile.lammps.%s Makefile.lammps' % msuffix
     else:
       cmd = 'cp Makefile.lammps.default Makefile.lammps'
     subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   else: print("Makefile.lammps exists. Please check its settings")
 
 # create 2 links in lib/mscg to MS-CG src dir
 
 if linkflag:
   print("Creating links to MS-CG include and lib files")
   if os.path.isfile("includelink") or os.path.islink("includelink"):
     os.remove("includelink")
   if os.path.isfile("liblink") or os.path.islink("liblink"):
     os.remove("liblink")
   cmd = 'ln -s "%s/src" includelink' % homedir
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   cmd = 'ln -s "%s/src" liblink' % homedir
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
diff --git a/lib/smd/Install.py b/lib/smd/Install.py
index fe0283563..1c270bea5 100644
--- a/lib/smd/Install.py
+++ b/lib/smd/Install.py
@@ -1,117 +1,123 @@
 #!/usr/bin/env python
 
 # Install.py tool to download, unpack, and point to the Eigen library
 # used to automate the steps described in the README file in this dir
 
 from __future__ import print_function
 import sys,os,re,glob,subprocess
-try: from urllib.request import urlretrieve as geturl
-except: from urllib import urlretrieve as geturl
 
 # help message
 
 help = """
-Syntax from src dir: make lib-smd
+Syntax from src dir: make lib-smd args="-b"
                  or: make lib-smd args="-p /usr/include/eigen3"
 
-Syntax from lib dir: python Install.py
+Syntax from lib dir: python Install.py -b
                  or: python Install.py -p /usr/include/eigen3"
                  or: python Install.py -v 3.3.4 -b
 
 specify one or more options, order does not matter
 
-  -b = download and unpack/configure the Eigen library (default)
+  -b = download and unpack/configure the Eigen library
   -p = specify folder holding an existing installation of Eigen
   -v = set version of Eigen library to download and set up (default = 3.3.4)
 
 
 Example:
 
 make lib-smd args="-b"   # download/build in default lib/smd/eigen-eigen-*
+make lib-smd args="-p /usr/include/eigen3" # use existing Eigen installation in /usr/include/eigen3
 """
 
 # settings
 
 version = '3.3.4'
 tarball = "eigen.tar.gz"
 
 # print error message or help
 
 def error(str=None):
   if not str: print(help)
   else: print("ERROR",str)
   sys.exit()
 
 # expand to full path name
 # process leading '~' or relative path
 
 def fullpath(path):
   return os.path.abspath(os.path.expanduser(path))
 
+def geturl(url,fname):
+  cmd = 'curl -L -o "%s" %s' % (fname,url)
+  txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
+  return txt
+
 # parse args
 
 args = sys.argv[1:]
 nargs = len(args)
+if nargs == 0: error()
 
 homepath = "."
 homedir = "eigen3"
 
-grabflag = True
-buildflag = True
+buildflag = False
 pathflag = False
 linkflag = True
 
 iarg = 0
 while iarg < nargs:
   if args[iarg] == "-v":
     if iarg+2 > nargs: error()
     version = args[iarg+1]
     iarg += 2
   elif args[iarg] == "-p":
     if iarg+2 > nargs: error()
     eigenpath = fullpath(args[iarg+1])
     pathflag = True
-    buildflag = False
     iarg += 2
   elif args[iarg] == "-b":
     buildflag = True
     iarg += 1
   else: error()
 
 homepath = fullpath(homepath)
 
 if (pathflag):
   if not os.path.isdir(eigenpath): error("Eigen path does not exist")
 
 if (buildflag and pathflag):
     error("Cannot use -b and -p flag at the same time")
 
+if (not buildflag and not pathflag):
+    error("Have to use either -b or -p flag")
+
 # download and unpack Eigen tarball
 # use glob to find name of dir it unpacks to
 
 if buildflag:
   print("Downloading Eigen ...")
   url = "http://bitbucket.org/eigen/eigen/get/%s.tar.gz" % version
   geturl(url,"%s/%s" % (homepath,tarball))
 
   print("Unpacking Eigen tarball ...")
   edir = glob.glob("%s/eigen-eigen-*" % homepath)
   for one in edir:
     if os.path.isdir(one):
       subprocess.check_output('rm -rf "%s"' % one,stderr=subprocess.STDOUT,shell=True)
   cmd = 'cd "%s"; tar -xzvf %s' % (homepath,tarball)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   edir = glob.glob("%s/eigen-eigen-*" % homepath)
   os.rename(edir[0],"%s/%s" % (homepath,homedir))
   os.remove(tarball)
 
 # create link in lib/smd to Eigen src dir
 
 if linkflag:
   print("Creating link to Eigen files")
   if os.path.isfile("includelink") or os.path.islink("includelink"):
     os.remove("includelink")
   if pathflag: linkdir = eigenpath
   else: linkdir = "%s/%s" % (homepath,homedir)
   cmd = 'ln -s "%s" includelink' % linkdir
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
diff --git a/lib/voronoi/Install.py b/lib/voronoi/Install.py
index 6db0495a3..5a246bbeb 100644
--- a/lib/voronoi/Install.py
+++ b/lib/voronoi/Install.py
@@ -1,135 +1,134 @@
 #!/usr/bin/env python
 
 # Install.py tool to download, unpack, build, and link to the Voro++ library
 # used to automate the steps described in the README file in this dir
 
 from __future__ import print_function
 import sys,os,re,subprocess
 
-try:
-  import ssl
-  try: from urllib.request import urlretrieve as geturl
-  except: from urllib import urlretrieve as geturl
-except:
-  def geturl(url,fname):
-    cmd = 'curl -L -o "%s" %s' % (fname,url)
-    txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
-    return txt
-
 # help message
 
 help = """
-Syntax from src dir: make lib-voronoi
+Syntax from src dir: make lib-voronoi args="-b"
                  or: make lib-voronoi args="-p /usr/local/voro++-0.4.6"
-                 or: make lib-voronoi args="-v voro++-0.4.6 -b"
-Syntax from lib dir: python Install.py -v voro++-0.4.6 -b
-                 or: python Install.py
+                 or: make lib-voronoi args="-b -v voro++-0.4.6"
+Syntax from lib dir: python Install.py -b -v voro++-0.4.6
+                 or: python Install.py -b
                  or: python Install.py -p /usr/local/voro++-0.4.6
 
 specify one or more options, order does not matter
 
-  -b = download and build the Voro++ library (default)
-  -p = specify folder of existing Voro++ installation 
+  -b = download and build the Voro++ library
+  -p = specify folder of existing Voro++ installation
   -v = set version of Voro++ to download and build (default voro++-0.4.6)
 
 Example:
 
 make lib-voronoi args="-b"   # download/build in lib/voronoi/voro++-0.4.6
+make lib-voronoi args="-p $HOME/voro++-0.4.6" # use existing Voro++ installation in $HOME/voro++-0.4.6
 """
 
 # settings
 
 version = "voro++-0.4.6"
 url = "http://math.lbl.gov/voro++/download/dir/%s.tar.gz" % version
 
 # print error message or help
 
 def error(str=None):
   if not str: print(help)
   else: print("ERROR",str)
   sys.exit()
 
 # expand to full path name
 # process leading '~' or relative path
 
 def fullpath(path):
   return os.path.abspath(os.path.expanduser(path))
 
+def geturl(url,fname):
+  cmd = 'curl -L -o "%s" %s' % (fname,url)
+  txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
+  return txt
+
 # parse args
 
 args = sys.argv[1:]
 nargs = len(args)
+if nargs == 0: error()
 
 homepath = "."
 homedir = version
 
-buildflag = True
+buildflag = False
 pathflag = False
 linkflag = True
 
 iarg = 0
 while iarg < nargs:
   if args[iarg] == "-v":
     if iarg+2 > nargs: error()
     version = args[iarg+1]
     iarg += 2
   elif args[iarg] == "-p":
     if iarg+2 > nargs: error()
     voropath = fullpath(args[iarg+1])
     pathflag = True
-    buildflag = False
     iarg += 2
   elif args[iarg] == "-b":
     buildflag = True
     iarg += 1
   else: error()
 
 homepath = fullpath(homepath)
 homedir = "%s/%s" % (homepath,version)
 
 if (pathflag):
     if not os.path.isdir(voropath): error("Voro++ path does not exist")
     homedir = voropath
 
 if (buildflag and pathflag):
     error("Cannot use -b and -p flag at the same time")
 
+if (not buildflag and not pathflag):
+    error("Have to use either -b or -p flag")
+
 # download and unpack Voro++ tarball
 
 if buildflag:
   print("Downloading Voro++ ...")
   geturl(url,"%s/%s.tar.gz" % (homepath,version))
 
   print("Unpacking Voro++ tarball ...")
   if os.path.exists("%s/%s" % (homepath,version)):
     cmd = 'rm -rf "%s/%s"' % (homepath,version)
     subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   cmd = 'cd "%s"; tar -xzvf %s.tar.gz' % (homepath,version)
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   os.remove("%s/%s.tar.gz" % (homepath,version))
   if os.path.basename(homedir) != version:
     if os.path.exists(homedir):
       cmd = 'rm -rf "%s"' % homedir
       subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
     os.rename("%s/%s" % (homepath,version),homedir)
 
 # build Voro++
 
 if buildflag:
   print("Building Voro++ ...")
   cmd = 'cd "%s"; make' % homedir
   txt = subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   print(txt.decode('UTF-8'))
 
 # create 2 links in lib/voronoi to Voro++ src dir
 
 if linkflag:
   print("Creating links to Voro++ include and lib files")
   if os.path.isfile("includelink") or os.path.islink("includelink"):
     os.remove("includelink")
   if os.path.isfile("liblink") or os.path.islink("liblink"):
     os.remove("liblink")
   cmd = 'ln -s "%s/src" includelink' % homedir
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
   cmd = 'ln -s "%s/src" liblink' % homedir
   subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)