aquasol 1.6.0

Thermodynamic and physico-chemical properties for water and aqueous solutions

General information

This package computes useful thermodynamic quantities for water and aqueous solutions (undersaturated, saturated and supersaturated). Is is divided in two modules: water (properties of pure water) and solutions (properties of aqueous solutions), which provide various functions to calculate properties of interest. There is also a list of useful constants in the constants.py module.

It is also possible to just see plots of the properties by running the package directly from a shell console with

python -m aquasol

The package is under CeCILL-2.1 license, which is equivalent to GNU-GPL (see license file and information below)

How to install:

pip install aquasol

WATER

Properties

The water module has the following functions(*), which return the respective properties of interest as a function of temperature:

• density_sat() for density on the liquid-vapor coexistence line (kg/m^3)
• density_atm() for density at ambient pressure 0.1 MPa (kg/m^3)
• dielectric_constant() for the dielectric constant at 0.1 MPa (-)
• diffusivity_in_air() for diffusivity of water vapor in air (m^2/s)
• surface_tension() for surface tension of pure water (N/m).
• vapor_pressure() for saturation vapor pressure of pure water (Pa),
• viscosity() for viscosity of liquid water (Pa.s)

The structure of the call for any property (replace property below by one of the function names above) is

from aquasol.water import property

value = property(T=25, unit='C', source=None)

Inputs

• T (int, float, array, list, or tuple): temperature
• unit (str, default 'C'): 'C' for Celsius, 'K' for Kelvin
• source (str, default None) : Source for the used equation, if None then the default source for the particular property is used.

Output

• Property in SI units, returned as numpy array if input is not a scalar.

Note

• See further below for dewpoint(), kelvin_pressure(), kelvin_humidity(), kelvin_radius() and molar_volume(), which work a bit differently.

(*) As of aquasol 1.5, the main functions (excluding dewpoint etc.) are now callable objects, which act as functions but have additional attributes, see Attributes and Methods below.

Examples

(See docstrings for more details)

from aquasol.water import vapor_pressure, surface_tension
from aquasol.water import density_atm, density_sat
from aquasol.water import diffusivity_in_air, viscosity

vapor_pressure()             # Saturation vapor pressure (Pa) at 25°C (3170 Pa)
vapor_pressure(298.15, 'K')        # same thing
vapor_pressure(source='Wexler')    # same thing, but according to Wexler
vapor_pressure(T=[5, 15, 25])          # psat at different temperatures in °C

surface_tension(T=[5, 15, 25])         # same, but for surface tension (N/m)

density_atm(4)               # density of water at atmospheric pressure at 4°C
density_sat(277.15, 'K')     # same thing, but on the coexistence line

diffusivity_in_air(27)  # Diffusivity of water vapor in air at 27°C

viscosity()         # Viscosity of liquid water at 25°C

dielectric_constant(T=20)   # Dielectric constant at 20°C ( = 80)

Attributes & Methods

The properties listed above are in fact (since version 1.5) extended functions (i.e. callable objects), with additional attributes and methods that can be useful in various contexts; below are some examples using vapor_pressure.

from aquasol.water import vapor_pressure

vapor_pressure()         # Saturation vapor pressure (Pa) at 25°C

vapor_pressure.sources         # all available sources
vapor_pressure.default_source  # source used by default if None is provided
vapor_pressure.get_source()          # return default source
vapor_pressure.get_source('Wexler')  # checks if source exists and returns it

vapor_pressure.quantity  # 'saturated vapor pressure'
vapor_pressure.unit      # '[Pa]'

It is also possible to access specific formulas (i.e. corresponding to a specific source), and get their properties.

formula = vapor_pressure.get_formula('Wexler')  # default formula if no arg.

formula.source  # 'Wexler'
formula.temperature_range  # validity range of expression
formula.temperature_unit   # 'C' or 'K', varies across formulas

formula.calculate(T=300)  # Return value at given T (input in temperature_unit)

Inverse and other property functions

Based on the functions above, some inverse and other properties are also provided:

• dewpoint()
• kelvin_pressure()
• kelvin_radius()
• kelvin_humidity()
• molar_volume()

Examples

(See docstrings for more details)

from aquasol.water import dewpoint, kelvin_radius, kelvin_humidity

dewpoint(p=1000)  # Dew point of a vapor at 1kPa
dewpoint(rh=50)  # Dew point at 50%RH and 25°C (default)
dewpoint('K', 300, rh=50)  # specify temperature
dewpoint(aw=[0.5, 0.7])     # It is possible to input lists, tuples, arrays

kelvin_pressure(rh=80)  # (liquid) Kelvin pressure corresponding to 80%RH
kelvin_pressure(aw=[0.5, 0.7, 0.9], T=20)  # at 20°C for 50%RH, 70%RH, 90%RH

kelvin_radius(aw=0.8)  # Kelvin radius at 80%RH and T=25°C
kelvin_radius(rh=80, ncurv=1)  # assume cylindrical meniscus instead of spherical

kelvin_humidity(r=4.7e-9)  # activity corresponding to Kelvin radius of 4.7 nm at 25°C
kelvin_humidity(r=4.7e-9, out='rh')  # same, but expressed in %RH instead of activity
kelvin_humidity(r=4.7e-9, ncurv=1, out='p')  # cylindrical interface, output as pressure
kelvin_humidity(P=[-30e6, -50e6])  # input can also be liquid pressure

molar_volume()  # molar volume of water at 25°C
molar_volume(T=30)  # at 30°C
molar_volume(condition='atm')  # using atmosph. density instead of sat.

Sources

Below are the sources for water vapor pressure (1, 2, 3), density (1, 4, 5), surface tension (6), diffusivity in air (7, 8), viscosity (9)

(1) Wagner, W. & Pruß, A. The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use. Journal of Physical and Chemical Reference Data 31, 387–535 (2002). [*]

(2) Wexler, A. & Greenspan, L. Vapor Pressure Equation for Water in the Range 0 to 100°C. Journal of Research of the National Bureau of Standards - A. Physics and Chemistry 75A, 213–245 (1971).

(3) Bridgeman, O. C. & Aldrich, E. W. Vapor Pressure Tables for Water. Journal of Heat Transfer 86, 279–286 (1964).

(4) Pátek, J., Hrubý, J., Klomfar, J., Součková, M. & Harvey, A. H. Reference Correlations for Thermophysical Properties of Liquid Water at 0.1MPa. Journal of Physical and Chemical Reference Data 38, 21–29 (2009). [*]

(5) Kell, G. S. Density, thermal expansivity, and compressibility of liquid water from 0.deg. to 150.deg.. Correlations and tables for atmospheric pressure and saturation reviewed and expressed on 1968 temperature scale. J. Chem. Eng. Data 20, 97–105 (1975).

(6) IAPWS Revised Release on Surface Tension of Ordinary Water Substance. Moscow, Russia, June 2014. [*]

(7) Massman, W. J. A review of the molecular diffusivities of H2O, CO2, CH4, CO, O3, SO2, NH3, N2O, NO, and NO2 in air, O2 and N2 near STP. Atmospheric Environment 32, 1111-1127 (1998).

(8) Marrero, T. R. and Mason E. A., Gaseous diffusion coeffcients. Journal of Physics and Chemistry Reference Data 1, 3-118 (1972)

(9) Huber, M. L. et al. New International Formulation for the Viscosity of H2O. Journal of Physical and Chemical Reference Data 38, 101-125 (2009). [*]

(10) Archer, D. G. & Wang, P. The Dielectric Constant of Water and Debye-Hückel Limiting Law Slopes. Journal of Physical and Chemical Reference Data 19, 371-411 (1990).

[*] Recommended by IAPWS.

SOLUTIONS

Properties

The solutions module has the following functions(**), which return the respective properties of interest as a function of solute concentration and temperature (when available) of an aqueous solution.

• density() for absolute (kg / m^3) or relative density,
• activity_coefficient() for molal activity coefficient of solute (dimensionless)
• water_activity() for solvent activity (dimensionless, range 0-1),
• surface_tension() for absolute surface tension (N/m) or relative (normalized by that of pure water at the same temperature).
• refractive_index() (dimensionless)
• electrical_conductivity() (S/m)
• solubility() (output unit can be chosen)

The following functions, which are based on some of the ones above, are also defined:

• osmotic_coefficient(): $\phi$, calculated using water_activity()
• osmotic_pressure(): $\Pi$, calculated using water_activity()
• aw_saturated(): water activity of saturated solutions (i.e., equilibrium humidity)
• debye_length(): Debye length as a function of temperature and concentration

The structure of the call for any property (replace property below by one of the function names above) is

data = property(solute='NaCl', T=25, unit='C', source=None, **concentration)

with an additional parameter relative=False where applicable.

Note that the solubility has a slightly different call:

data = solubility(solute='NaCl', T=25, unit='C', source=None, out='m')

Inputs

• solute (str): solute name, default 'NaCl'
• T (float): temperature (default 25)
• unit (str, default 'C'): 'C' for Celsius, 'K' for Kelvin
• source (str, default None) : Source for the used equation, if None then gets the default source for the particular solute (defined in submodules).
• **concentration: kwargs with any unit that is allowed by convert() (see below), e.g. property(m=5.3) for molality.
• when applicable: relative (bool, default False): True for relative density
• for solubility, the out parameter is the unit in which the solubility will be expressed (see convert() below)

Output

• Property in SI units, returned as numpy array if input is not a scalar.

Note: similarly to temperature, the values in **concentration can be an array, list or tuple, however if it's the case, temperature needs to be a scalar.

(**) As of aquasol 1.5, the main property functions (excluding osmotic pressure etc.) are now callable objects, which act as functions but have additional attributes, see Attributes and Methods below.*

Examples

from aquasol.solutions import water_activity, activity_coefficient
from aquasol.solutions import osmotic_pressure, osmotic_coefficient
from aquasol.solutions import density, surface_tension, refractive_index
from aquasol.solutions import solubility, aw_saturated
from aquasol.solutions import ionic_strength, debye_length

# Water activity (dimensionless, 'aw') ---------------------------------------
water_activity(x=0.1)            # NaCl solution, mole fraction 10%, 25°C
water_activity(r=0.3)           # solution when mixing 55g NaCl with 100g H2O
water_activity('LiCl', w=0.3, T=70)  # LiCl solution, 30% weight fraction, 70°C
water_activity(solute='CaCl2', m=[2, 4, 6])  # for several molalities (mol/kg)

# Other ways to express water activity:
osmotic_pressure(m=5)
osmotic_coefficient(x=0.1, solute='LiCl')

# Molal activity coefficient (dimensionless, 'gamma') ------------------------
activity_coefficient(m=6.1)            # ~ Saturated NaCl solution, 25°C
activity_coefficient(solute='Na2SO3', m=2.2)  # Na2SO3 at 2.2 mol/kg

# Density (absolute, kg / m^3, or relative) ----------------------------------
density(source='Tang', x=0.23)  # supersaturatad NaCl, 25°C, using Tang equation
density(c=5000, relative=True)  # relative density of NaCl, 5 mol/L.
density('LiCl', w=[0.11, 0.22, 0.51])  # for several weight fractions of LiCl

# Surface tension (N / m) ----------------------------------------------------
surface_tension(r=0.55)           # solution when mixing 55g NaCl with 100g H2O
surface_tension(c=5000, relative=True)  # sigma / sigma(H2O) at 5 mol/L of NaCl
surface_tension('CaCl2', 353, 'K', c=5e3)    # CaCl2, 300K, 5 mol/L
surface_tension(x=[0.02, 0.04, 0.08], T=21)  # iterable mole fraction

# Refractive index -----------------------------------------------------------
refractive_index(c=4321)  # concentration of 4.321 mol/L of NaCl, 25°C
refractive_index('KCl', T=22, r=[0.1, 0.175])  # various mass ratios of KCl

# Electrical conductivity ----------------------------------------------------
electrical_conductivity('KCl', m=0.1)  # molality of 0.1 mol/L of KCl, 25°C
electrical_conductivity('KCl', T=50, x=[0.01, 0.02])  # various mole fractions
electrical_conductivity('KCl', T=[0, 25, 50], m=1)  # various mole fractions

# Solubility -----------------------------------------------------------------
solubility()       # NaCl at 25°C
solubility(T=10)   # NaCl at 10°C
solubility('KCl')  # KCl, 25°C
solubility('Na2SO4,10H20', T=10)  # Mirabilite at T=10°C

# Other ways to express solubility:
aw_saturated()        # Activity of saturated NaCl solution = 0.753
aw_saturated('LiCl')  # etc.

# Debye length and ionic strength
debye_length('Na2SO4', c=100)  # sodium sulfate at 100mM
ionic_strength('KCl', m=2)     # molal ionic strength

Attributes & Methods

Similarly to the water module, the properties listed above are in fact (since version 1.5) extended functions (i.e. callable objects), with additional attributes and methods that can be useful in various contexts; below are some examples using density.

from aquasol.solutions import density

density(m=6)  # Density of an NaCl solution at 6 mol/kg

density.quantity  # 'density'
density.unit  #   # '[kg/m^3]'

density.solutes  # All solutes available for the given property
density.default_solute  # solute used by default if None provided
density.get_solute()  # get solute or defautl solute, see docstring

density.sources  # Dictionary of sources available for each solute
density.default_sources  # Dict of sources used by default if None provided
density.get_source()   # get source or default source, see docstring

It is also possible to access specific formulas (i.e. corresponding to a specific source and solute), and get their properties.

formula = density.get_formula(solute='KCl', source='Krumgalz')

formula.source  # 'Krumgalz'
formula.temperature_range  # validity range of expression in temperature
formula.temperature_unit   # 'C' or 'K', varies across formulas
formula.solute             # solute of interest

formula.concentration_range  # validity range of expression in concentration
formula.concentration_unit   # 'm' 'w', 'x', etc., varies across formulas

formula.with_water_reference  # if true, returns a tuple with value at c=0 and value at c
formula.calculate(m=2.2)      # Value at given concentration (in concentration_unit)

Inverse property functions

The aw_to_conc calculates what concentration of solute is necessary to reach a specific water activity:

aw_to_conc(a, out='w', solute='NaCl', T=25, unit='C', source=None):

For example:

aw_to_conc(0.8)  # weight fraction of NaCl to have a humidity of 80%RH
aw_to_conc([0.6, 0.85], out='m')  # molality of NaCl to get 60%RH and 85%RH
aw_to_conc(0.33, 'r', 'LiCl', T=50)  # in terms of mass ratio, for LiCl at 50°C

Other functions

The solutions module also has a function to convert between concentration units:

value_out = convert(value, unit_in, unit_out, solute='NaCl', density_source=None)

where unit_in and unit_out can be in the following list:

• 'm' (molality, mol/kg)
• 'c' (molarity, mol/m^3)
• 'x' (mole fraction)
• 'w' (weight fraction)
• 'r' (ratio solute mass to solvent mass).

By default, solute is 'NaCl'. When converting to/from molarity, one must also use a formula to calculate the density of the solution. It's possible to specify a formula different than the default one by providing an argument to the density_source argument.

NOTE: In case of issues such as ValueError: Requested values higher than the higher limit of the image, try playing with the density_wmin and density_wmax parameters in convert().

One can access more elaborate quantities with the following functions:

Iy = ionic_strength(solute, **concentration)

for ionic strength, which can be expressed in terms of molarity, molality or mole fraction. Which version is chosen among these three possibilities depend on the input parameters, e.g. m=5.3 for molality, x=0.08 for mole fraction, c=5000 for molarity.

y1, y2 = ion_quantities(solute, **concentration)

which calculate quantities of individual ions within the solution instead of considering the solute as a whole. Similarly, the result depends on the input unit, which can also be only among m, c or x.

See docstrings for more details.

Available Solutes

Sorted by alphabetical order. When available, the sources are written in parentheses. For convert, an X means available.

Solute	Water Activity	Activity Coeff.	Density	Surface Tension	Refr. Index	Elec. Conduct.	Solubility	Convert (*)
CaCl2	(1)		(1,3,14)	(1,6)	(7)			X
KCl	(8,13)	(8,13)	(3,14)	(6)	(7)	(9)	(13)	X
KI			(3,14)					X
LiBr	(19,20)	(20)					(18)	-
LiCl	(1,19,20)	(20)	(1,14)	(1)			(17)	X
MgCl2			(3,14)	(6)				X
Na2SO4	(2,12,13)	(12,13)	(10,14,15)	(6)			(13)	X
NaCl	(2,8,12,13,20)	(8,12,13,20)	(3,4,5,11,14,15)	(6,11)	(7)		(13,16,17)	X

(*) Solutes with no density data cannot use conversion to/from molarity ('c') but all other conversions work. They are noted with - instead of X.

Sources

(1) Conde, M. R., Properties of aqueous solutions of lithium and calcium chlorides: formulations for use in air conditioning equipment design. International Journal of Thermal Sciences 43, 367–382 (2004).

(2) Clegg, S. L., Brimblecombe, P., Liang, Z. & Chan, C. K., Thermodynamic Properties of Aqueous Aerosols to High Supersaturation: II — A Model of the System Na+ Cl− NO3- SO42- H2O at 298.15 K. Aerosol Science and Technology 27, 345–366 (1997).

(3) Al Ghafri, S., Maitland, G. C. & Trusler, J. P. M., Densities of Aqueous MgCl 2 (aq), CaCl 2 (aq), KI(aq), NaCl(aq), KCl(aq), AlCl 3 (aq), and (0.964 NaCl + 0.136 KCl)(aq) at Temperatures Between (283 and 472) K, Pressures up to 68.5 MPa, and Molalities up to 6 mol·kg –1. Journal of Chemical & Engineering Data 57, 1288–1304 (2012).

(4) Tang, I. N., Chemical and size effects of hygroscopic aerosols on light scattering coefficients. Journal of Geophysical Research: Atmospheres 101, 19245–19250 (1996).

(5) Simion, A. I., Grigoras, C., Rosu, A.-M. & Gavrilă, L. Mathematical modelling of density and viscosity of NaCl aqueous solutions. Journal of Agroalimentary Processing and Technologies 21, 41–52 (2015).

(6) Dutcher, C. S., Wexler, A. S. & Clegg, S. L. Surface Tensions of Inorganic Multicomponent Aqueous Electrolyte Solutions and Melts. J. Phys. Chem. A 114, 12216–12230 (2010).

(7) Tan, C.-Y. & Huang, Y.-X. Dependence of Refractive Index on Concentration and Temperature in Electrolyte Solution, Polar Solution, Nonpolar Solution, and Protein Solution. J. Chem. Eng. Data 60, 2827–2833 (2015).

(8) Tang, I. N., Munkelwitz, H. R. & Wang, N. Water activity measurements with single suspended droplets: The NaCl-H2O and KCl-H2O systems. Journal of Colloid and Interface Science 114, 409–415 (1986).

(9) McKee, C. B., An Accurate Equation for the Electrolytic Conductivity of Potassium Chloride Solutions. J Solution Chem 38, 1155-1172 (2009).

(10) Tang, I. N. & Munkelwitz, H. R., Simultaneous Determination of Refractive Index and Density of an Evaporating Aqueous Solution Droplet. Aerosol Science and Technology 15, 201–207 (1991).

(11) Talreja-Muthreja, T., Linnow, K., Enke, D. & Steiger. M. Deliquescence of NaCl Confined in Nanoporous Silica. Langmuir 38, 10963-10974 (2022).

(12) Steiger, M., Crystal growth in porous materials—I: The crystallization pressure of large crystals. Journal of Crystal Growth 282, 455-469 (2005).

(13) Steiger, M., Kiekbusch, J. & Nicolai, An improved model incorporating Pitzer's equations for calculation of thermodynamic properties of pore solutions implemented into an efficient program code. Construction and Building Materials 22, 1841-1850 (2008).

(14) Krumgalz, B. S., Pogorelsky, R. & Pitzer, K. S., Volumetric Properties of Single Aqueous Electrolytes from Zero to Saturation Concentration at 298.15 K Represented by Pitzer's Ion-Interaction Equations. Journal of Physical and Chemical Reference Data 25, 663-689 (1996).

(15) Clegg, S. L. & Wexler, A. S., Densities and Apparent Molar Volumes of Atmospherically Important Electrolyte Solutions. 1. The Solutes H2SO4, HNO3, HCl, Na2SO4, NaNO3, NaCl, (NH4)2SO4, NH4NO3, and NH4Cl from 0 to 50°C, Including Extrapolations to Very Low Temperature and to the Pure Liquid State, and NaHSO4, NaOH, and NH3 at 25°C. J. Phys. Chem. A 115, 3393-3460 (2011).

(16) Sparrow, B. S., Empirical equations for the thermodynamic properties of aqueous sodium chloride. Desalination 159, 161-170 (2003).

(17) CRC Handbook of Chemistry and Physics: A Ready-Reference Book of Chemical and Physical Data. (CRC Press, Boca Raton London New York, 2023).

(18) Duvall, K. N., Dirksen, J. A. & Ring, T. A. Ostwald-Meyers Metastable Region in LiBr Crystallization—Comparison of Measurements with Predictions. Journal of Colloid and Interface Science 239, 391-398 (2001).

(19) Patil, K. R., Tripathi, A. D., Pathak, G. & Katti, S. S. Thermodynamic Properties of Aqueous Electrolyte Solutions. 1. Vapor Pressure of Aqueous Solutions of LiCI, LiBr, and LiI. J. Chem. Eng. Data 35, 166-168 (1990)

(20) Pitzer, K. S. & Mayorga, G., Thermodynamics of electrolytes. II. Activity and osmotic coefficients for strong electrolytes with one or both ions univalent. J. Phys. Chem. 77, 2300-2308 (1973).

Constants

The constants.py file includes useful values including critical point data, molecular weights of species, dissociation numbers etc. Use the function molar_mass to get the molar mass (in kg/mol) of a specific solute from the available solutes, e.g.:

from aquasol.constants import Mw           # molar mass of water (kg/mol)
from aquasol.constants import molar_mass   # molar mass of specific solute
from aquasol.constants import get_solute   # returns solute object with info

Na2SO4 = get_solute('Na2SO4')

molar_mass('Na2SO4')            # 0.142 kg/mol
Na2SO4.molar_mass               # same
Na2SO4.molecular_weight         # same but in Daltons (142)

z_m, z_x = Na2SO4.charges          # (1, -2) for Na(1+), SO4(2-)
nu_m, nu_x = Na2SO4.stoichiometry   # (2, 1) for Na(2) SO4(1)

Shortcut functions

For rapid calculations without much typing, the following shortcuts are provided:

original function	shortcut
water.vapor_pressure()	ps()
water.dewpoint()	dp()
water.kelvin_pressure()	kp()
water.kelvin_radius()	kr()
water.kelvin_humidity()	kh()
water.molar_volume()	vm()
solutions.water_activity()	aw()
solutions.aw_to_conc()	ac()
solutions.convert()	cv()

For example, the two following imports are equivalent:

from aquasol.solutions import water_activity as aw
from aquasol import aw

Information

Package requirements

• numpy
• pynverse
• [optional] matplotlib (only if running the package directly as a main file to plot the properties)

Python requirements

Python : >= 3.6

Author

Olivier Vincent

([e-mail])

Contributors

Marine Poizat (2019), Léo Martin (2020), Hugo Bellezza (2023)

License

CeCILL v.2.1 (equivalent to GNU GPL, see https://cecill.info/) See LICENSE file.

Copyright Olivier Vincent (2020-2024) ([e-mail])

This software is a computer program whose purpose is to provide the properties of water and aqueous solutions as a function of temperature and/or concentration (along with other useful tools).

This software is governed by the CeCILL license under French law and abiding by the rules of distribution of free software. You can use, modify and/ or redistribute the software under the terms of the CeCILL license as circulated by CEA, CNRS and INRIA at the following URL "http://www.cecill.info".

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For the purpose of this Agreement, when the following expressions commence with a capital letter, they shall have the following meaning:

Agreement: means this license agreement, and its possible subsequent versions and annexes.

Software: means the software in its Object Code and/or Source Code form and, where applicable, its documentation, "as is" when the Licensee accepts the Agreement.

Initial Software: means the Software in its Source Code and possibly its Object Code form and, where applicable, its documentation, "as is" when it is first distributed under the terms and conditions of the Agreement.

Modified Software: means the Software modified by at least one Contribution.

Source Code: means all the Software's instructions and program lines to which access is required so as to modify the Software.

Object Code: means the binary files originating from the compilation of the Source Code.

Holder: means the holder(s) of the economic rights over the Initial Software.

Licensee: means the Software user(s) having accepted the Agreement.

Contributor: means a Licensee having made at least one Contribution.

Licensor: means the Holder, or any other individual or legal entity, who distributes the Software under the Agreement.

Contribution: means any or all modifications, corrections, translations, adaptations and/or new functions integrated into the Software by any or all Contributors, as well as any or all Internal Modules.

Module: means a set of sources files including their documentation that enables supplementary functions or services in addition to those offered by the Software.

External Module: means any or all Modules, not derived from the Software, so that this Module and the Software run in separate address spaces, with one calling the other when they are run.

Internal Module: means any or all Module, connected to the Software so that they both execute in the same address space.

GNU GPL: means the GNU General Public License version 2 or any subsequent version, as published by the Free Software Foundation Inc.

GNU Affero GPL: means the GNU Affero General Public License version 3 or any subsequent version, as published by the Free Software Foundation Inc.

EUPL: means the European Union Public License version 1.1 or any subsequent version, as published by the European Commission.

Parties: mean both the Licensee and the Licensor.

These expressions may be used both in singular and plural form.

Article 2 - PURPOSE

The purpose of the Agreement is the grant by the Licensor to the Licensee of a non-exclusive, transferable and worldwide license for the Software as set forth in Article 5 <#scope> hereinafter for the whole term of the protection granted by the rights over said Software.

Article 3 - ACCEPTANCE

3.1 The Licensee shall be deemed as having accepted the terms and conditions of this Agreement upon the occurrence of the first of the following events:

• (i) loading the Software by any or all means, notably, by downloading from a remote server, or by loading from a physical medium;
• (ii) the first time the Licensee exercises any of the rights granted hereunder.

3.2 One copy of the Agreement, containing a notice relating to the characteristics of the Software, to the limited warranty, and to the fact that its use is restricted to experienced users has been provided to the Licensee prior to its acceptance as set forth in Article 3.1 <#accepting> hereinabove, and the Licensee hereby acknowledges that it has read and understood it.

Article 4 - EFFECTIVE DATE AND TERM


  4.1 EFFECTIVE DATE

The Agreement shall become effective on the date when it is accepted by the Licensee as set forth in Article 3.1 <#accepting>.

  4.2 TERM

The Agreement shall remain in force for the entire legal term of protection of the economic rights over the Software.

Article 5 - SCOPE OF RIGHTS GRANTED

The Licensor hereby grants to the Licensee, who accepts, the following rights over the Software for any or all use, and for the term of the Agreement, on the basis of the terms and conditions set forth hereinafter.

Besides, if the Licensor owns or comes to own one or more patents protecting all or part of the functions of the Software or of its components, the Licensor undertakes not to enforce the rights granted by these patents against successive Licensees using, exploiting or modifying the Software. If these patents are transferred, the Licensor undertakes to have the transferees subscribe to the obligations set forth in this paragraph.

  5.1 RIGHT OF USE

The Licensee is authorized to use the Software, without any limitation as to its fields of application, with it being hereinafter specified that this comprises:

1. permanent or temporary reproduction of all or part of the Software by any or all means and in any or all form.

2. loading, displaying, running, or storing the Software on any or all medium.

3. entitlement to observe, study or test its operation so as to determine the ideas and principles behind any or all constituent elements of said Software. This shall apply when the Licensee carries out any or all loading, displaying, running, transmission or storage operation as regards the Software, that it is entitled to carry out hereunder.

   5.2 ENTITLEMENT TO MAKE CONTRIBUTIONS

The right to make Contributions includes the right to translate, adapt, arrange, or make any or all modifications to the Software, and the right to reproduce the resulting software.

The Licensee is authorized to make any or all Contributions to the Software provided that it includes an explicit notice that it is the author of said Contribution and indicates the date of the creation thereof.

  5.3 RIGHT OF DISTRIBUTION

In particular, the right of distribution includes the right to publish, transmit and communicate the Software to the general public on any or all medium, and by any or all means, and the right to market, either in consideration of a fee, or free of charge, one or more copies of the Software by any means.

The Licensee is further authorized to distribute copies of the modified or unmodified Software to third parties according to the terms and conditions set forth hereinafter.

    5.3.1 DISTRIBUTION OF SOFTWARE WITHOUT MODIFICATION

The Licensee is authorized to distribute true copies of the Software in Source Code or Object Code form, provided that said distribution complies with all the provisions of the Agreement and is accompanied by:

1. a copy of the Agreement,

2. a notice relating to the limitation of both the Licensor's warranty and liability as set forth in Articles 8 and 9,

and that, in the event that only the Object Code of the Software is redistributed, the Licensee allows effective access to the full Source Code of the Software for a period of at least three years from the distribution of the Software, it being understood that the additional acquisition cost of the Source Code shall not exceed the cost of the data transfer.

    5.3.2 DISTRIBUTION OF MODIFIED SOFTWARE

When the Licensee makes a Contribution to the Software, the terms and conditions for the distribution of the resulting Modified Software become subject to all the provisions of this Agreement.

The Licensee is authorized to distribute the Modified Software, in source code or object code form, provided that said distribution complies with all the provisions of the Agreement and is accompanied by:

1. a copy of the Agreement,

2. a notice relating to the limitation of both the Licensor's warranty and liability as set forth in Articles 8 and 9,

and, in the event that only the object code of the Modified Software is redistributed,

3. a note stating the conditions of effective access to the full source code of the Modified Software for a period of at least three years from the distribution of the Modified Software, it being understood that the additional acquisition cost of the source code shall not exceed the cost of the data transfer.

   5.3.3 DISTRIBUTION OF EXTERNAL MODULES
   

When the Licensee has developed an External Module, the terms and conditions of this Agreement do not apply to said External Module, that may be distributed under a separate license agreement.

    5.3.4 COMPATIBILITY WITH OTHER LICENSES

The Licensee can include a code that is subject to the provisions of one of the versions of the GNU GPL, GNU Affero GPL and/or EUPL in the Modified or unmodified Software, and distribute that entire code under the terms of the same version of the GNU GPL, GNU Affero GPL and/or EUPL.

The Licensee can include the Modified or unmodified Software in a code that is subject to the provisions of one of the versions of the GNU GPL, GNU Affero GPL and/or EUPL and distribute that entire code under the terms of the same version of the GNU GPL, GNU Affero GPL and/or EUPL.

Article 6 - INTELLECTUAL PROPERTY


  6.1 OVER THE INITIAL SOFTWARE

The Holder owns the economic rights over the Initial Software. Any or all use of the Initial Software is subject to compliance with the terms and conditions under which the Holder has elected to distribute its work and no one shall be entitled to modify the terms and conditions for the distribution of said Initial Software.

The Holder undertakes that the Initial Software will remain ruled at least by this Agreement, for the duration set forth in Article 4.2 <#term>.

  6.2 OVER THE CONTRIBUTIONS

The Licensee who develops a Contribution is the owner of the intellectual property rights over this Contribution as defined by applicable law.

  6.3 OVER THE EXTERNAL MODULES

The Licensee who develops an External Module is the owner of the intellectual property rights over this External Module as defined by applicable law and is free to choose the type of agreement that shall govern its distribution.

  6.4 JOINT PROVISIONS

The Licensee expressly undertakes:

1. not to remove, or modify, in any manner, the intellectual property notices attached to the Software;

2. to reproduce said notices, in an identical manner, in the copies of the Software modified or not.

The Licensee undertakes not to directly or indirectly infringe the intellectual property rights on the Software of the Holder and/or Contributors, and to take, where applicable, vis-à-vis its staff, any and all measures required to ensure respect of said intellectual property rights of the Holder and/or Contributors.

Article 7 - RELATED SERVICES

7.1 Under no circumstances shall the Agreement oblige the Licensor to provide technical assistance or maintenance services for the Software.

However, the Licensor is entitled to offer this type of services. The terms and conditions of such technical assistance, and/or such maintenance, shall be set forth in a separate instrument. Only the Licensor offering said maintenance and/or technical assistance services shall incur liability therefor.

7.2 Similarly, any Licensor is entitled to offer to its licensees, under its sole responsibility, a warranty, that shall only be binding upon itself, for the redistribution of the Software and/or the Modified Software, under terms and conditions that it is free to decide. Said warranty, and the financial terms and conditions of its application, shall be subject of a separate instrument executed between the Licensor and the Licensee.

Article 8 - LIABILITY

8.1 Subject to the provisions of Article 8.2, the Licensee shall be entitled to claim compensation for any direct loss it may have suffered from the Software as a result of a fault on the part of the relevant Licensor, subject to providing evidence thereof.

8.2 The Licensor's liability is limited to the commitments made under this Agreement and shall not be incurred as a result of in particular: (i) loss due the Licensee's total or partial failure to fulfill its obligations, (ii) direct or consequential loss that is suffered by the Licensee due to the use or performance of the Software, and (iii) more generally, any consequential loss. In particular the Parties expressly agree that any or all pecuniary or business loss (i.e. loss of data, loss of profits, operating loss, loss of customers or orders, opportunity cost, any disturbance to business activities) or any or all legal proceedings instituted against the Licensee by a third party, shall constitute consequential loss and shall not provide entitlement to any or all compensation from the Licensor.

Article 9 - WARRANTY

9.1 The Licensee acknowledges that the scientific and technical state-of-the-art when the Software was distributed did not enable all possible uses to be tested and verified, nor for the presence of possible defects to be detected. In this respect, the Licensee's attention has been drawn to the risks associated with loading, using, modifying and/or developing and reproducing the Software which are reserved for experienced users.

The Licensee shall be responsible for verifying, by any or all means, the suitability of the product for its requirements, its good working order, and for ensuring that it shall not cause damage to either persons or properties.

9.2 The Licensor hereby represents, in good faith, that it is entitled to grant all the rights over the Software (including in particular the rights set forth in Article 5 <#scope>).

9.3 The Licensee acknowledges that the Software is supplied "as is" by the Licensor without any other express or tacit warranty, other than that provided for in Article 9.2 <#good-faith> and, in particular, without any warranty as to its commercial value, its secured, safe, innovative or relevant nature.

Specifically, the Licensor does not warrant that the Software is free from any error, that it will operate without interruption, that it will be compatible with the Licensee's own equipment and software configuration, nor that it will meet the Licensee's requirements.

9.4 The Licensor does not either expressly or tacitly warrant that the Software does not infringe any third party intellectual property right relating to a patent, software or any other property right. Therefore, the Licensor disclaims any and all liability towards the Licensee arising out of any or all proceedings for infringement that may be instituted in respect of the use, modification and redistribution of the Software. Nevertheless, should such proceedings be instituted against the Licensee, the Licensor shall provide it with technical and legal expertise for its defense. Such technical and legal expertise shall be decided on a case-by-case basis between the relevant Licensor and the Licensee pursuant to a memorandum of understanding. The Licensor disclaims any and all liability as regards the Licensee's use of the name of the Software. No warranty is given as regards the existence of prior rights over the name of the Software or as regards the existence of a trademark.

Article 10 - TERMINATION

10.1 In the event of a breach by the Licensee of its obligations hereunder, the Licensor may automatically terminate this Agreement thirty (30) days after notice has been sent to the Licensee and has remained ineffective.

10.2 A Licensee whose Agreement is terminated shall no longer be authorized to use, modify or distribute the Software. However, any licenses that it may have granted prior to termination of the Agreement shall remain valid subject to their having been granted in compliance with the terms and conditions hereof.

Article 11 - MISCELLANEOUS


  11.1 EXCUSABLE EVENTS

Neither Party shall be liable for any or all delay, or failure to perform the Agreement, that may be attributable to an event of force majeure, an act of God or an outside cause, such as defective functioning or interruptions of the electricity or telecommunications networks, network paralysis following a virus attack, intervention by government authorities, natural disasters, water damage, earthquakes, fire, explosions, strikes and labor unrest, war, etc.

11.2 Any failure by either Party, on one or more occasions, to invoke one or more of the provisions hereof, shall under no circumstances be interpreted as being a waiver by the interested Party of its right to invoke said provision(s) subsequently.

11.3 The Agreement cancels and replaces any or all previous agreements, whether written or oral, between the Parties and having the same purpose, and constitutes the entirety of the agreement between said Parties concerning said purpose. No supplement or modification to the terms and conditions hereof shall be effective as between the Parties unless it is made in writing and signed by their duly authorized representatives.

11.4 In the event that one or more of the provisions hereof were to conflict with a current or future applicable act or legislative text, said act or legislative text shall prevail, and the Parties shall make the necessary amendments so as to comply with said act or legislative text. All other provisions shall remain effective. Similarly, invalidity of a provision of the Agreement, for any reason whatsoever, shall not cause the Agreement as a whole to be invalid.

  11.5 LANGUAGE

The Agreement is drafted in both French and English and both versions are deemed authentic.

Article 12 - NEW VERSIONS OF THE AGREEMENT

12.1 Any person is authorized to duplicate and distribute copies of this Agreement.

12.2 So as to ensure coherence, the wording of this Agreement is protected and may only be modified by the authors of the License, who reserve the right to periodically publish updates or new versions of the Agreement, each with a separate number. These subsequent versions may address new issues encountered by Free Software.

12.3 Any Software distributed under a given version of the Agreement may only be subsequently distributed under the same version of the Agreement or a subsequent version, subject to the provisions of Article 5.3.4 <#compatibility>.

Article 13 - GOVERNING LAW AND JURISDICTION

13.1 The Agreement is governed by French law. The Parties agree to endeavor to seek an amicable solution to any disagreements or disputes that may arise during the performance of the Agreement.

13.2 Failing an amicable solution within two (2) months as from their occurrence, and unless emergency proceedings are necessary, the disagreements or disputes shall be referred to the Paris Courts having jurisdiction, by the more diligent Party.