diff --git a/DDCore/python/DD4hep.py b/DDCore/python/DD4hep.py
new file mode 100644
index 0000000000000000000000000000000000000000..7f3df654f7b9b97bc6ea11c643fa14fda04e8594
--- /dev/null
+++ b/DDCore/python/DD4hep.py
@@ -0,0 +1,17 @@
+#==========================================================================
+# AIDA Detector description implementation
+#--------------------------------------------------------------------------
+# Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
+# All rights reserved.
+#
+# For the licensing terms see $DD4hepINSTALL/LICENSE.
+# For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
+#
+#==========================================================================
+#
+# BACKWARDS COMPATIBILITY FILE!
+# The namespace "DD4hep" is deprecated. Please use "dd4hep" instead.
+#
+#==========================================================================
+from dd4hep_base import *
+print 'DEPRECATION WARNING The namespace "DD4hep" is deprecated. Please use "dd4hep" instead.'
diff --git a/DDCore/python/dd4hep.py b/DDCore/python/dd4hep.py
new file mode 100644
index 0000000000000000000000000000000000000000..43d853450f858f69d180e6096caf8d3085733858
--- /dev/null
+++ b/DDCore/python/dd4hep.py
@@ -0,0 +1,12 @@
+#==========================================================================
+# AIDA Detector description implementation
+#--------------------------------------------------------------------------
+# Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
+# All rights reserved.
+#
+# For the licensing terms see $DD4hepINSTALL/LICENSE.
+# For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
+#
+#==========================================================================
+from dd4hep_base import *
+import_units()
diff --git a/DDG4/python/DD4hep.py b/DDCore/python/dd4hep_base.py
similarity index 94%
rename from DDG4/python/DD4hep.py
rename to DDCore/python/dd4hep_base.py
index f09d8df29deadf5de2e9b2e83792b0c2bb801a26..aab3df4eb71a10f6054441b58f2e04c8d98d9e52 100644
--- a/DDG4/python/DD4hep.py
+++ b/DDCore/python/dd4hep_base.py
@@ -225,3 +225,18 @@ def import_tgeo():
import_tgeo()
import_geometry()
+
+try:
+ from ROOT import TGeoUnit as TGeoUnits
+ def import_units():
+ def import_unit(nam):
+ setattr(name_space,nam,getattr(TGeoUnits,nam))
+ items = dir(TGeoUnits)
+ for u in items:
+ if u[0] != '_':
+ import_unit(u)
+ return len(items)
+except:
+ print 'WARNING: No units from TGeoUnit can be imported. This is normal for ROOT < 6.12.0'
+ def import_units():
+ return 0
diff --git a/DDG4/python/DDG4.py b/DDG4/python/DDG4.py
index 2057ca7e3b9e8772bab6a933bcd8037f5448ca3f..30e9381b102a577a61045664bf255e28e59526eb 100644
--- a/DDG4/python/DDG4.py
+++ b/DDG4/python/DDG4.py
@@ -9,7 +9,7 @@
#
#==========================================================================
import logging
-from DD4hep import *
+from dd4hep_base import *
logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.DEBUG)
def loadDDG4():
@@ -34,6 +34,7 @@ def loadDDG4():
from ROOT import dd4hep as module
return module
+
# We are nearly there ....
current = __import__(__name__)
def _import_class(ns,nam):
diff --git a/DDG4/python/SystemOfUnits.py b/DDG4/python/SystemOfUnits.py
index 894a8048da69939983d41f5f84910e944aa8f0cf..9ebf1a3ac79306bbb05bb0d0189084f820201be9 100644
--- a/DDG4/python/SystemOfUnits.py
+++ b/DDG4/python/SystemOfUnits.py
@@ -1,278 +1,17 @@
-# File: AthenaCommon/share/SystemOfUnits.py
-# Author: Wim Lavrijsen (LBNL, WLavrijsen@lbl.gov)
-# Created: 01/21/04
-# Last: 01/21/04
-
-# This script is a direct adaptation of CLHEP/Units/SystemOfUnits.h
-# and the following is the originial CLHEP comment:
+#==========================================================================
+# AIDA Detector description implementation
+#--------------------------------------------------------------------------
+# Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
+# All rights reserved.
#
-# -----
-# HEP coherent system of Units
+# For the licensing terms see $DD4hepINSTALL/LICENSE.
+# For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
#
-# This file has been provided to CLHEP by Geant4 (simulation toolkit for HEP).
+#==========================================================================
#
-# The basic units are :
-# millimeter (millimeter)
-# nanosecond (nanosecond)
-# Mega electron Volt (MeV)
-# positron charge (eplus)
-# degree Kelvin (kelvin)
-# the amount of substance (mole)
-# luminous intensity (candela)
-# radian (radian)
-# steradian (steradian)
+# BACKWARDS COMPATIBILITY FILE!
+# The namespace "DD4hep" is deprecated. Please use "dd4hep" instead.
#
-# Below is a non exhaustive list of derived and pratical units
-# (i.e. mostly the SI units).
-# You can add your own units.
-#
-# The SI numerical value of the positron charge is defined here,
-# as it is needed for conversion factor : positron charge = e_SI (coulomb)
-#
-# The others physical constants are defined in the header file :
-# PhysicalConstants.h
-#
-# Authors: M.Maire, S.Giani
-#
-# History:
-#
-# 06.02.96 Created.
-# 28.03.96 Added miscellaneous constants.
-# 05.12.97 E.Tcherniaev: Redefined pascal (to avoid warnings on WinNT)
-# 20.05.98 names: meter, second, gram, radian, degree
-# (from Brian.Lasiuk@yale.edu (STAR)). Added luminous units.
-# 05.08.98 angstrom, picobarn, microsecond, picosecond, petaelectronvolt
-# 01.03.01 parsec
-# -----
-
-#
-# Length [L]
-#
-millimeter = 1.
-millimeter2 = millimeter*millimeter
-millimeter3 = millimeter*millimeter*millimeter
-
-centimeter = 10.*millimeter
-centimeter2 = centimeter*centimeter
-centimeter3 = centimeter*centimeter*centimeter
-
-meter = 1000.*millimeter
-meter2 = meter*meter
-meter3 = meter*meter*meter
-
-kilometer = 1000.*meter
-kilometer2 = kilometer*kilometer
-kilometer3 = kilometer*kilometer*kilometer
-
-parsec = 3.0856775807e+16*meter
-
-micrometer = 1.e-6 *meter
-nanometer = 1.e-9 *meter
-angstrom = 1.e-10*meter
-fermi = 1.e-15*meter
-
-barn = 1.e-28*meter2
-millibarn = 1.e-3 *barn
-microbarn = 1.e-6 *barn
-nanobarn = 1.e-9 *barn
-picobarn = 1.e-12*barn
-
-# symbols
-mm = millimeter
-mm2 = millimeter2
-mm3 = millimeter3
-
-cm = centimeter
-cm2 = centimeter2
-cm3 = centimeter3
-
-m = meter
-m2 = meter2
-m3 = meter3
-
-km = kilometer
-km2 = kilometer2
-km3 = kilometer3
-
-pc = parsec
-
-#
-# Angle
-#
-radian = 1.
-milliradian = 1.e-3*radian
-degree = (3.14159265358979323846/180.0)*radian
-
-steradian = 1.
-
-# symbols
-rad = radian
-mrad = milliradian
-sr = steradian
-deg = degree
-
-#
-# Time [T]
-#
-nanosecond = 1.
-second = 1.e+9 *nanosecond
-millisecond = 1.e-3 *second
-microsecond = 1.e-6 *second
-picosecond = 1.e-12*second
-femtosecond = 1.e-15*second
-
-hertz = 1./second
-kilohertz = 1.e+3*hertz
-megahertz = 1.e+6*hertz
-
-# symbols
-ns = nanosecond
-s = second
-ms = millisecond
-
-#
-# Electric charge [Q]
-#
-eplus = 1. # positron charge
-e_SI = 1.60217733e-19 # positron charge in coulomb
-coulomb = eplus/e_SI # coulomb = 6.24150 e+18 * eplus
-
-#
-# Energy [E]
-#
-megaelectronvolt = 1.
-electronvolt = 1.e-6*megaelectronvolt
-kiloelectronvolt = 1.e-3*megaelectronvolt
-gigaelectronvolt = 1.e+3*megaelectronvolt
-teraelectronvolt = 1.e+6*megaelectronvolt
-petaelectronvolt = 1.e+9*megaelectronvolt
-
-joule = electronvolt/e_SI # joule = 6.24150 e+12 * MeV
-
-# symbols
-MeV = megaelectronvolt
-eV = electronvolt
-keV = kiloelectronvolt
-GeV = gigaelectronvolt
-TeV = teraelectronvolt
-PeV = petaelectronvolt
-
-#
-# Mass [E][T^2][L^-2]
-#
-kilogram = joule*second*second/(meter*meter)
-gram = 1.e-3*kilogram
-milligram = 1.e-3*gram
-
-# symbols
-kg = kilogram
-g = gram
-mg = milligram
-
-#
-# Power [E][T^-1]
-#
-watt = joule/second # watt = 6.24150 e+3 * MeV/ns
-
-#
-# Force [E][L^-1]
-#
-newton = joule/meter # newton = 6.24150 e+9 * MeV/mm
-
-#
-# Pressure [E][L^-3]
-#
-hep_pascal = newton/m2 # pascal = 6.24150 e+3 * MeV/mm3
-pascal = hep_pascal # a trick to avoid warnings
-bar = 100000*pascal # bar = 6.24150 e+8 * MeV/mm3
-atmosphere = 101325*pascal # atm = 6.32420 e+8 * MeV/mm3
-
-#
-# Electric current [Q][T^-1]
-#
-ampere = coulomb/second # ampere = 6.24150 e+9 * eplus/ns
-milliampere = 1.e-3*ampere
-microampere = 1.e-6*ampere
-nanoampere = 1.e-9*ampere
-
-#
-# Electric potential [E][Q^-1]
-#
-megavolt = megaelectronvolt/eplus
-kilovolt = 1.e-3*megavolt
-volt = 1.e-6*megavolt
-
-#
-# Electric resistance [E][T][Q^-2]
-#
-ohm = volt/ampere # ohm = 1.60217e-16*(MeV/eplus)/(eplus/ns)
-
-#
-# Electric capacitance [Q^2][E^-1]
-#
-farad = coulomb/volt # farad = 6.24150e+24 * eplus/Megavolt
-millifarad = 1.e-3*farad
-microfarad = 1.e-6*farad
-nanofarad = 1.e-9*farad
-picofarad = 1.e-12*farad
-
-#
-# Magnetic Flux [T][E][Q^-1]
-#
-weber = volt*second # weber = 1000*megavolt*ns
-
-#
-# Magnetic Field [T][E][Q^-1][L^-2]
-#
-tesla = volt*second/meter2 # tesla =0.001*megavolt*ns/mm2
-
-gauss = 1.e-4*tesla
-kilogauss = 1.e-1*tesla
-
-#
-# Inductance [T^2][E][Q^-2]
-#
-henry = weber/ampere # henry = 1.60217e-7*MeV*(ns/eplus)**2
-
-#
-# Temperature
-#
-kelvin = 1.
-
-#
-# Amount of substance
-#
-mole = 1.
-
-#
-# Activity [T^-1]
-#
-becquerel = 1./second
-curie = 3.7e+10 * becquerel
-
-#
-# Absorbed dose [L^2][T^-2]
-#
-gray = joule/kilogram
-
-#
-# Luminous intensity [I]
-#
-candela = 1.
-
-#
-# Luminous flux [I]
-#
-lumen = candela*steradian
-
-#
-# Illuminance [I][L^-2]
-#
-lux = lumen/meter2
-
-#
-# Miscellaneous
-#
-perCent = 0.01
-perThousand = 0.001
-perMillion = 0.000001
+#==========================================================================
+from g4units import *
+print 'DEPRECATION WARNING The namespace "SystemOfUnits" is deprecated. Please use "g4units" instead.'
diff --git a/DDCore/python/SystemOfUnits.py b/DDG4/python/g4units.py
similarity index 81%
rename from DDCore/python/SystemOfUnits.py
rename to DDG4/python/g4units.py
index 8657d5c7a6362d8131e3e2418a53f5b69d8e9e30..894a8048da69939983d41f5f84910e944aa8f0cf 100644
--- a/DDCore/python/SystemOfUnits.py
+++ b/DDG4/python/g4units.py
@@ -1,278 +1,278 @@
-# File: AthenaCommon/share/SystemOfUnits.py
-# Author: Wim Lavrijsen (LBNL, WLavrijsen@lbl.gov)
-# Created: 01/21/04
-# Last: 01/21/04
-
-# This script is a direct adaptation of CLHEP/Units/SystemOfUnits.h
-# and the following is the originial CLHEP comment:
-#
-# -----
-# HEP coherent system of Units
-#
-# This file has been provided to CLHEP by Geant4 (simulation toolkit for HEP).
-#
-# The basic units are :
-# millimeter (millimeter)
-# nanosecond (nanosecond)
-# Mega electron Volt (MeV)
-# positron charge (eplus)
-# degree Kelvin (kelvin)
-# the amount of substance (mole)
-# luminous intensity (candela)
-# radian (radian)
-# steradian (steradian)
-#
-# Below is a non exhaustive list of derived and pratical units
-# (i.e. mostly the SI units).
-# You can add your own units.
-#
-# The SI numerical value of the positron charge is defined here,
-# as it is needed for conversion factor : positron charge = e_SI (coulomb)
-#
-# The others physical constants are defined in the header file :
-# PhysicalConstants.h
-#
-# Authors: M.Maire, S.Giani
-#
-# History:
-#
-# 06.02.96 Created.
-# 28.03.96 Added miscellaneous constants.
-# 05.12.97 E.Tcherniaev: Redefined pascal (to avoid warnings on WinNT)
-# 20.05.98 names: meter, second, gram, radian, degree
-# (from Brian.Lasiuk@yale.edu (STAR)). Added luminous units.
-# 05.08.98 angstrom, picobarn, microsecond, picosecond, petaelectronvolt
-# 01.03.01 parsec
-# -----
-
-#
-# Length [L]
-#
-millimeter = 0.1
-millimeter2 = millimeter*millimeter
-millimeter3 = millimeter*millimeter*millimeter
-
-centimeter = 10.*millimeter
-centimeter2 = centimeter*centimeter
-centimeter3 = centimeter*centimeter*centimeter
-
-meter = 1000.*millimeter
-meter2 = meter*meter
-meter3 = meter*meter*meter
-
-kilometer = 1000.*meter
-kilometer2 = kilometer*kilometer
-kilometer3 = kilometer*kilometer*kilometer
-
-parsec = 3.0856775807e+16*meter
-
-micrometer = 1.e-6 *meter
-nanometer = 1.e-9 *meter
-angstrom = 1.e-10*meter
-fermi = 1.e-15*meter
-
-barn = 1.e-28*meter2
-millibarn = 1.e-3 *barn
-microbarn = 1.e-6 *barn
-nanobarn = 1.e-9 *barn
-picobarn = 1.e-12*barn
-
-# symbols
-mm = millimeter
-mm2 = millimeter2
-mm3 = millimeter3
-
-cm = centimeter
-cm2 = centimeter2
-cm3 = centimeter3
-
-m = meter
-m2 = meter2
-m3 = meter3
-
-km = kilometer
-km2 = kilometer2
-km3 = kilometer3
-
-pc = parsec
-
-#
-# Angle
-#
-radian = 1.
-milliradian = 1.e-3*radian
-degree = (3.14159265358979323846/180.0)*radian
-
-steradian = 1.
-
-# symbols
-rad = radian
-mrad = milliradian
-sr = steradian
-deg = degree
-
-#
-# Time [T]
-#
-nanosecond = 1.
-second = 1.e+9 *nanosecond
-millisecond = 1.e-3 *second
-microsecond = 1.e-6 *second
-picosecond = 1.e-12*second
-femtosecond = 1.e-15*second
-
-hertz = 1./second
-kilohertz = 1.e+3*hertz
-megahertz = 1.e+6*hertz
-
-# symbols
-ns = nanosecond
-s = second
-ms = millisecond
-
-#
-# Electric charge [Q]
-#
-eplus = 1. # positron charge
-e_SI = 1.60217733e-19 # positron charge in coulomb
-coulomb = eplus/e_SI # coulomb = 6.24150 e+18 * eplus
-
-#
-# Energy [E]
-#
-megaelectronvolt = 1.
-electronvolt = 1.e-6*megaelectronvolt
-kiloelectronvolt = 1.e-3*megaelectronvolt
-gigaelectronvolt = 1.e+3*megaelectronvolt
-teraelectronvolt = 1.e+6*megaelectronvolt
-petaelectronvolt = 1.e+9*megaelectronvolt
-
-joule = electronvolt/e_SI # joule = 6.24150 e+12 * MeV
-
-# symbols
-MeV = megaelectronvolt
-eV = electronvolt
-keV = kiloelectronvolt
-GeV = gigaelectronvolt
-TeV = teraelectronvolt
-PeV = petaelectronvolt
-
-#
-# Mass [E][T^2][L^-2]
-#
-kilogram = joule*second*second/(meter*meter)
-gram = 1.e-3*kilogram
-milligram = 1.e-3*gram
-
-# symbols
-kg = kilogram
-g = gram
-mg = milligram
-
-#
-# Power [E][T^-1]
-#
-watt = joule/second # watt = 6.24150 e+3 * MeV/ns
-
-#
-# Force [E][L^-1]
-#
-newton = joule/meter # newton = 6.24150 e+9 * MeV/mm
-
-#
-# Pressure [E][L^-3]
-#
-hep_pascal = newton/m2 # pascal = 6.24150 e+3 * MeV/mm3
-pascal = hep_pascal # a trick to avoid warnings
-bar = 100000*pascal # bar = 6.24150 e+8 * MeV/mm3
-atmosphere = 101325*pascal # atm = 6.32420 e+8 * MeV/mm3
-
-#
-# Electric current [Q][T^-1]
-#
-ampere = coulomb/second # ampere = 6.24150 e+9 * eplus/ns
-milliampere = 1.e-3*ampere
-microampere = 1.e-6*ampere
-nanoampere = 1.e-9*ampere
-
-#
-# Electric potential [E][Q^-1]
-#
-megavolt = megaelectronvolt/eplus
-kilovolt = 1.e-3*megavolt
-volt = 1.e-6*megavolt
-
-#
-# Electric resistance [E][T][Q^-2]
-#
-ohm = volt/ampere # ohm = 1.60217e-16*(MeV/eplus)/(eplus/ns)
-
-#
-# Electric capacitance [Q^2][E^-1]
-#
-farad = coulomb/volt # farad = 6.24150e+24 * eplus/Megavolt
-millifarad = 1.e-3*farad
-microfarad = 1.e-6*farad
-nanofarad = 1.e-9*farad
-picofarad = 1.e-12*farad
-
-#
-# Magnetic Flux [T][E][Q^-1]
-#
-weber = volt*second # weber = 1000*megavolt*ns
-
-#
-# Magnetic Field [T][E][Q^-1][L^-2]
-#
-tesla = volt*second/meter2 # tesla =0.001*megavolt*ns/mm2
-
-gauss = 1.e-4*tesla
-kilogauss = 1.e-1*tesla
-
-#
-# Inductance [T^2][E][Q^-2]
-#
-henry = weber/ampere # henry = 1.60217e-7*MeV*(ns/eplus)**2
-
-#
-# Temperature
-#
-kelvin = 1.
-
-#
-# Amount of substance
-#
-mole = 1.
-
-#
-# Activity [T^-1]
-#
-becquerel = 1./second
-curie = 3.7e+10 * becquerel
-
-#
-# Absorbed dose [L^2][T^-2]
-#
-gray = joule/kilogram
-
-#
-# Luminous intensity [I]
-#
-candela = 1.
-
-#
-# Luminous flux [I]
-#
-lumen = candela*steradian
-
-#
-# Illuminance [I][L^-2]
-#
-lux = lumen/meter2
-
-#
-# Miscellaneous
-#
-perCent = 0.01
-perThousand = 0.001
-perMillion = 0.000001
+# File: AthenaCommon/share/SystemOfUnits.py
+# Author: Wim Lavrijsen (LBNL, WLavrijsen@lbl.gov)
+# Created: 01/21/04
+# Last: 01/21/04
+
+# This script is a direct adaptation of CLHEP/Units/SystemOfUnits.h
+# and the following is the originial CLHEP comment:
+#
+# -----
+# HEP coherent system of Units
+#
+# This file has been provided to CLHEP by Geant4 (simulation toolkit for HEP).
+#
+# The basic units are :
+# millimeter (millimeter)
+# nanosecond (nanosecond)
+# Mega electron Volt (MeV)
+# positron charge (eplus)
+# degree Kelvin (kelvin)
+# the amount of substance (mole)
+# luminous intensity (candela)
+# radian (radian)
+# steradian (steradian)
+#
+# Below is a non exhaustive list of derived and pratical units
+# (i.e. mostly the SI units).
+# You can add your own units.
+#
+# The SI numerical value of the positron charge is defined here,
+# as it is needed for conversion factor : positron charge = e_SI (coulomb)
+#
+# The others physical constants are defined in the header file :
+# PhysicalConstants.h
+#
+# Authors: M.Maire, S.Giani
+#
+# History:
+#
+# 06.02.96 Created.
+# 28.03.96 Added miscellaneous constants.
+# 05.12.97 E.Tcherniaev: Redefined pascal (to avoid warnings on WinNT)
+# 20.05.98 names: meter, second, gram, radian, degree
+# (from Brian.Lasiuk@yale.edu (STAR)). Added luminous units.
+# 05.08.98 angstrom, picobarn, microsecond, picosecond, petaelectronvolt
+# 01.03.01 parsec
+# -----
+
+#
+# Length [L]
+#
+millimeter = 1.
+millimeter2 = millimeter*millimeter
+millimeter3 = millimeter*millimeter*millimeter
+
+centimeter = 10.*millimeter
+centimeter2 = centimeter*centimeter
+centimeter3 = centimeter*centimeter*centimeter
+
+meter = 1000.*millimeter
+meter2 = meter*meter
+meter3 = meter*meter*meter
+
+kilometer = 1000.*meter
+kilometer2 = kilometer*kilometer
+kilometer3 = kilometer*kilometer*kilometer
+
+parsec = 3.0856775807e+16*meter
+
+micrometer = 1.e-6 *meter
+nanometer = 1.e-9 *meter
+angstrom = 1.e-10*meter
+fermi = 1.e-15*meter
+
+barn = 1.e-28*meter2
+millibarn = 1.e-3 *barn
+microbarn = 1.e-6 *barn
+nanobarn = 1.e-9 *barn
+picobarn = 1.e-12*barn
+
+# symbols
+mm = millimeter
+mm2 = millimeter2
+mm3 = millimeter3
+
+cm = centimeter
+cm2 = centimeter2
+cm3 = centimeter3
+
+m = meter
+m2 = meter2
+m3 = meter3
+
+km = kilometer
+km2 = kilometer2
+km3 = kilometer3
+
+pc = parsec
+
+#
+# Angle
+#
+radian = 1.
+milliradian = 1.e-3*radian
+degree = (3.14159265358979323846/180.0)*radian
+
+steradian = 1.
+
+# symbols
+rad = radian
+mrad = milliradian
+sr = steradian
+deg = degree
+
+#
+# Time [T]
+#
+nanosecond = 1.
+second = 1.e+9 *nanosecond
+millisecond = 1.e-3 *second
+microsecond = 1.e-6 *second
+picosecond = 1.e-12*second
+femtosecond = 1.e-15*second
+
+hertz = 1./second
+kilohertz = 1.e+3*hertz
+megahertz = 1.e+6*hertz
+
+# symbols
+ns = nanosecond
+s = second
+ms = millisecond
+
+#
+# Electric charge [Q]
+#
+eplus = 1. # positron charge
+e_SI = 1.60217733e-19 # positron charge in coulomb
+coulomb = eplus/e_SI # coulomb = 6.24150 e+18 * eplus
+
+#
+# Energy [E]
+#
+megaelectronvolt = 1.
+electronvolt = 1.e-6*megaelectronvolt
+kiloelectronvolt = 1.e-3*megaelectronvolt
+gigaelectronvolt = 1.e+3*megaelectronvolt
+teraelectronvolt = 1.e+6*megaelectronvolt
+petaelectronvolt = 1.e+9*megaelectronvolt
+
+joule = electronvolt/e_SI # joule = 6.24150 e+12 * MeV
+
+# symbols
+MeV = megaelectronvolt
+eV = electronvolt
+keV = kiloelectronvolt
+GeV = gigaelectronvolt
+TeV = teraelectronvolt
+PeV = petaelectronvolt
+
+#
+# Mass [E][T^2][L^-2]
+#
+kilogram = joule*second*second/(meter*meter)
+gram = 1.e-3*kilogram
+milligram = 1.e-3*gram
+
+# symbols
+kg = kilogram
+g = gram
+mg = milligram
+
+#
+# Power [E][T^-1]
+#
+watt = joule/second # watt = 6.24150 e+3 * MeV/ns
+
+#
+# Force [E][L^-1]
+#
+newton = joule/meter # newton = 6.24150 e+9 * MeV/mm
+
+#
+# Pressure [E][L^-3]
+#
+hep_pascal = newton/m2 # pascal = 6.24150 e+3 * MeV/mm3
+pascal = hep_pascal # a trick to avoid warnings
+bar = 100000*pascal # bar = 6.24150 e+8 * MeV/mm3
+atmosphere = 101325*pascal # atm = 6.32420 e+8 * MeV/mm3
+
+#
+# Electric current [Q][T^-1]
+#
+ampere = coulomb/second # ampere = 6.24150 e+9 * eplus/ns
+milliampere = 1.e-3*ampere
+microampere = 1.e-6*ampere
+nanoampere = 1.e-9*ampere
+
+#
+# Electric potential [E][Q^-1]
+#
+megavolt = megaelectronvolt/eplus
+kilovolt = 1.e-3*megavolt
+volt = 1.e-6*megavolt
+
+#
+# Electric resistance [E][T][Q^-2]
+#
+ohm = volt/ampere # ohm = 1.60217e-16*(MeV/eplus)/(eplus/ns)
+
+#
+# Electric capacitance [Q^2][E^-1]
+#
+farad = coulomb/volt # farad = 6.24150e+24 * eplus/Megavolt
+millifarad = 1.e-3*farad
+microfarad = 1.e-6*farad
+nanofarad = 1.e-9*farad
+picofarad = 1.e-12*farad
+
+#
+# Magnetic Flux [T][E][Q^-1]
+#
+weber = volt*second # weber = 1000*megavolt*ns
+
+#
+# Magnetic Field [T][E][Q^-1][L^-2]
+#
+tesla = volt*second/meter2 # tesla =0.001*megavolt*ns/mm2
+
+gauss = 1.e-4*tesla
+kilogauss = 1.e-1*tesla
+
+#
+# Inductance [T^2][E][Q^-2]
+#
+henry = weber/ampere # henry = 1.60217e-7*MeV*(ns/eplus)**2
+
+#
+# Temperature
+#
+kelvin = 1.
+
+#
+# Amount of substance
+#
+mole = 1.
+
+#
+# Activity [T^-1]
+#
+becquerel = 1./second
+curie = 3.7e+10 * becquerel
+
+#
+# Absorbed dose [L^2][T^-2]
+#
+gray = joule/kilogram
+
+#
+# Luminous intensity [I]
+#
+candela = 1.
+
+#
+# Luminous flux [I]
+#
+lumen = candela*steradian
+
+#
+# Illuminance [I][L^-2]
+#
+lux = lumen/meter2
+
+#
+# Miscellaneous
+#
+perCent = 0.01
+perThousand = 0.001
+perMillion = 0.000001
diff --git a/DDParsers/include/Evaluator/DD4hepUnits.h b/DDParsers/include/Evaluator/DD4hepUnits.h
index f3f10c35b57cdbbb1040c43821291d301f7572cf..1bb728f87fc1c468a395b2624c67e8b72191ac73 100644
--- a/DDParsers/include/Evaluator/DD4hepUnits.h
+++ b/DDParsers/include/Evaluator/DD4hepUnits.h
@@ -27,7 +27,18 @@
#ifndef DD4HEP_TGEOUNITS_H
#define DD4HEP_TGEOUNITS_H
-/// Utility namespace to support TGeo units.
+#include "RVersion.h"
+
+// We use the ROOT system units if they are avalible
+#if ROOT_VERSION_CODE >= ROOT_VERSION(6,12,0)
+#include "TGeoSystemOfUnits.h"
+/// Main dd4hep namespace. We must import here the ROOT TGeo units
+namespace dd4hep {
+ using namespace TGeoUnit;
+}
+#else
+
+/// Main dd4hep namespace. We must import here the ROOT TGeo units
namespace dd4hep {
//namespace units {
@@ -392,4 +403,6 @@ namespace dd4hep {
static const double universe_mean_density = 1.e-25 * g / cm3;
//}
}
+#endif
+
#endif /* DD4HEP_TGEOUNITS_H */