Cantera

The Cantera development team is pleased to announce the availability of Cantera 2.5.1. There have been 1000 commits to Cantera since the release of Cantera 2.4.0 in August 2018. We have closed or merged more than [250 pull requests](https://github.com/Cantera/cantera/pulls?q=is%3Apr+is%3Aclosed+updated%3A%3E%3D2018-08-24) and [100 issues](https://github.com/Cantera/cantera/issues?q=is%3Aissue+is%3Aclosed+updated%3A%3E%3D2018-08-24). The complete list of changes can be found on the [Cantera Wiki page](https://github.com/Cantera/cantera/wiki/Complete-git-log-between-v2.4.0-and-v2.5.1), and a summary of new features, changes, and bugs fixed in this release is included below, with links to the associated Pull Requests on GitHub.

Cantera 2.5 introduces a new input file format, based on the [YAML](https://yaml.org/) data format. This format supersedes the CTI and XML (sometimes called CTML) formats that Cantera has used for many years. Converter scripts from CTI and XML to YAML (`cti2yaml` and `ctml2yaml`), as well as from CHEMKIN (CK) format to YAML (`ck2yaml`), are provided with this release. You can use these scripts in the same way that the old `ck2cti` script was used. All users are encouraged to switch their input files to the new format.

Instructions for installing Cantera 2.5 are available on the [Cantera website](https://cantera.org/install/index.html). Available options include Conda, native installers for Windows and macOS, Ubuntu packages, and compiling from source.

Thank you to the following contributors to Cantera 2.5:

[12Chao](https://github.com/12Chao), [agarwalrounak](https://github.com/agarwalrounak), [arghdos](https://github.com/arghdos), [band-a-prend](https://github.com/band-a-prend), [BangShiuh](https://github.com/BangShiuh), [bryanwweber](https://github.com/bryanwweber), [CyberDrudge](https://github.com/CyberDrudge), [decaluwe](https://github.com/decaluwe), [dholland88](https://github.com/dholland88), [g3bk47](https://github.com/g3bk47), [inducer](https://github.com/inducer), [ischoegl](https://github.com/ischoegl), [jsantner](https://github.com/jsantner), [korffdm](https://github.com/korffdm), [kyleniemeyer](https://github.com/kyleniemeyer), [lavdwall](https://github.com/lavdwall), [lionkey](https://github.com/lionkey), [manikmayur](https://github.com/manikmayur), [mgashwinkumar](https://github.com/mgashwinkumar), [paulblum](https://github.com/paulblum), [rwest](https://github.com/rwest), [sameshl](https://github.com/sameshl), [sin-ha](https://github.com/sin-ha), [speth](https://github.com/speth), [spinnau](https://github.com/spinnau), [ThanasisMattas](https://github.com/ThanasisMattas), [tsikes](https://github.com/tsikes), [wbessler](https://github.com/wbessler)

<details>
<summary><strong>Click here to see the complete Changelog</strong></summary>
<h2>New Features:</h2>
<ul>
<li>Added a new, YAML-based input file format (<a href="https://github.com/Cantera/cantera/pull/584">#584</a>, <a href="https://github.com/Cantera/cantera/pull/663">#663</a>, <a href="https://github.com/Cantera/cantera/pull/664">#664</a>, <a href="https://github.com/Cantera/cantera/pull/671">#671</a>, <a href="https://github.com/Cantera/cantera/pull/693">#693</a>, <a href="https://github.com/Cantera/cantera/pull/707">#707</a>, <a href="https://github.com/Cantera/cantera/pull/708">#708</a>, <a href="https://github.com/Cantera/cantera/pull/716">#716</a>, <a href="https://github.com/Cantera/cantera/pull/723">#723</a>, <a href="https://github.com/Cantera/cantera/pull/738">#738</a>, <a href="https://github.com/Cantera/cantera/pull/750">#750</a>, <a href="https://github.com/Cantera/cantera/pull/764">#764</a>, <a href="https://github.com/Cantera/cantera/pull/768">#768</a>, <a href="https://github.com/Cantera/cantera/pull/773">#773</a>, <a href="https://github.com/Cantera/cantera/pull/784">#784</a>, <a href="https://github.com/Cantera/cantera/pull/794">#794</a>, <a href="https://github.com/Cantera/cantera/pull/795">#795</a>, <a href="https://github.com/Cantera/cantera/pull/813">#813</a>, <a href="https://github.com/Cantera/cantera/pull/855">#855</a>, <a href="https://github.com/Cantera/cantera/pull/857">#857</a>, <a href="https://github.com/Cantera/cantera/pull/866">#866</a>, <a href="https://github.com/Cantera/cantera/pull/869">#869, <a href="https://github.com/Cantera/cantera/pull/880">#880</a>, <a href="https://github.com/Cantera/cantera/pull/897">#897</a>, <a href="https://github.com/Cantera/cantera/pull/899">#899</a>, <a href="https://github.com/Cantera/cantera/pull/961">#961</a>, <a href="https://github.com/Cantera/cantera/pull/970">#970</a>, <a href="https://github.com/Cantera/cantera/pull/941">#941</a>, <a href="https://github.com/Cantera/cantera/pull/974">#974</a>)</li>
<li>Add interface for reading and writing 1D Flame and SolutionArray objects from/to HDF5 files (<a href="https://github.com/Cantera/cantera/pull/680">#680</a>, <a href="https://github.com/Cantera/cantera/pull/687">#687</a>, <a href="https://github.com/Cantera/cantera/pull/805">#805</a>, <a href="https://github.com/Cantera/cantera/pull/840">#840</a>, <a href="https://github.com/Cantera/cantera/pull/860">#860</a>, <a href="https://github.com/Cantera/cantera/pull/871">#871</a>, <a href="https://github.com/Cantera/cantera/pull/900">#900</a>, <a href="https://github.com/Cantera/cantera/pull/943">#943</a>, <a href="https://github.com/Cantera/cantera/pull/931">#931</a>)</li>
<li>Add BinarySolutionTabulatedThermo class, which implements implements tabulated standard state thermodynamics in a binary solution. (<a href="https://github.com/Cantera/cantera/pull/563">#563</a>, <a href="https://github.com/Cantera/cantera/pull/606">#606</a>, <a href="https://github.com/Cantera/cantera/pull/637">#637</a>, <a href="https://github.com/Cantera/cantera/pull/640">#640</a>, <a href="https://github.com/Cantera/cantera/pull/725">#725</a>)</li>
<li>Introduce C++ Solution class to simplify creation of coupled ThermoPhase, Kinetics, and Transport objects (<a href="https://github.com/Cantera/cantera/pull/696">#696</a>, <a href="https://github.com/Cantera/cantera/pull/735">#735</a>)</li>
<li>Determine Redlich-Kwong parameters from a database of critical property data (<a href="https://github.com/Cantera/cantera/pull/574">#574</a>, <a href="https://github.com/Cantera/cantera/pull/576">#576</a>, <a href="https://github.com/cantera/cantera/commit/33e198f7e527dee6a97869d6677d2da9b58247b1"><code>33e198f</code></a>, <a href="https://github.com/cantera/cantera/commit/ebb93cb5a23591ca3badb186940e5b1a89e8a411"><code>ebb93cb</code></a>)</li>
<li>Make transport property calculations available for pure fluid water phases (<a href="https://github.com/Cantera/cantera/pull/558">#558</a>)</li>
<li>Make InterfaceKinetics.advance_coverages_to_steady_state available in the Python interface (<a href="https://github.com/Cantera/cantera/pull/592">#592</a>, <a href="https://github.com/Cantera/cantera/pull/610">#610</a>)</li>
<li>Add functions for returning the phase of matter for ThermoPhase objects (<a href="https://github.com/Cantera/cantera/pull/722">#722</a>, <a href="https://github.com/Cantera/cantera/pull/839">#839</a>)</li>
<li>Add new ReactorNet::advanceTowards method to combine benefits of both the 'step' and 'advance' methods; see 'reactor3.py' example (<a href="https://github.com/Cantera/cantera/pull/629">#629</a>, <a href="https://github.com/Cantera/cantera/pull/756">#756</a>)</li>
<li>Enable setting the maximum number of CVODEs steps in the Python interface (<a href="https://github.com/Cantera/cantera/pull/581">#581</a>)</li>
<li>Add factories for FlowDevice and Wall objects, to enable creation of user-defined derived classes (<a href="https://github.com/Cantera/cantera/pull/632">#632</a>)</li>
<li>Allow classes derived from StFlow to have additional state variables (<a href="https://github.com/Cantera/cantera/pull/624">#624</a>)</li>
<li>Add wrappers to make "piecewise-Gibbs" and "NASA9" species thermo objects accessible in Python (<a href="https://github.com/Cantera/cantera/pull/711">#711</a>)</li>
<li>Add set_equivalence_ratio function to SolutionArray objects (<a href="https://github.com/Cantera/cantera/pull/677">#677</a>)</li>
<li>Add ability to sort SolutionArray objects (<a href="https://github.com/Cantera/cantera/pull/688">#688</a>)</li>
<li>Support use of Sundials versions up to 5.7 (<a href="https://github.com/cantera/cantera/commit/5e226535de33a73dd59429eb54ef5d157d0afaa1"><code>5e22653</code></a>, <a href="https://github.com/Cantera/cantera/pull/672">#672</a>, <a href="https://github.com/Cantera/cantera/pull/780">#780</a>, <a href="https://github.com/Cantera/cantera/pull/814">#814</a>, <a href="https://github.com/Cantera/cantera/pull/974">#974</a>)</li>
<li>Add functions for setting species aliases and finding isomers (<a href="https://github.com/Cantera/cantera/pull/714">#714</a>, <a href="https://github.com/Cantera/cantera/pull/876">#876</a>)</li>
<li>Added 'warn_user' function as a consistent way of issuing warnings from C++ (<a href="https://github.com/Cantera/cantera/pull/741">#741</a>)</li>
<li>Add get/set equivalenceRatio/mixtureFraction functions to C++ (<a href="https://github.com/Cantera/cantera/pull/851">#851</a>)</li>
<li>Make getDeltaEnthalpies available in the Matlab interface (<a href="https://github.com/Cantera/cantera/pull/659">#659</a>)</li>
<li>Add 'TabulatedFunction' class for providing time-varying reactor inputs specified by tabular input (<a href="https://github.com/Cantera/cantera/pull/797">#797</a>)</li>
<li>Add plug flow reactor example in MATLAB (<a href="https://github.com/Cantera/cantera/pull/701">#701</a>)</li>
<li>Make liquid-water-IAPWS95 available as a phase model (<a href="https://github.com/Cantera/cantera/pull/921">#921</a>)</li>
<li>Make species charge information available in Python (<a href="https://github.com/Cantera/cantera/pull/863">#863</a>)</li>
<li>Add 'kinetics_species_name' and 'kinetics_species_names' functions to Python interface (<a href="https://github.com/cantera/cantera/commit/5601ee906741a539b8316ad9dad0cc7dbf4d6d68"><code>5601ee9</code></a>)</li>
<li>Added 'list_data_files' function to Python module (<a href="https://github.com/Cantera/cantera/pull/589">#589</a>)</li>
<li>Add 'fast_fail_tests' option to SCons (<a href="https://github.com/Cantera/cantera/pull/772">#772</a>)</li>
<li>Add some functions which were missing from the Fortran interface (<a href="https://github.com/Cantera/cantera/pull/828">#828</a>, <a href="https://github.com/Cantera/cantera/pull/858">#858</a>, <a href="https://github.com/Cantera/cantera/pull/870">#870</a>)</li>
<li>Provide const versions of certain functions (<a href="https://github.com/Cantera/cantera/pull/850">#850</a>, <a href="https://github.com/cantera/cantera/commit/9aa507a0988e9b12724f1c25ef23a67f4b04cd27"><code>9aa507a</code></a>)</li>
<li>Expand '~' as user homedir shortcut when adding data directories (<a href="https://github.com/cantera/cantera/commit/ca8700fdd406f148dd27bb238fc748f00ede69f4"><code>ca8700f</code></a>)</li>
</ul>

<h2>Changes to existing features:</h2>
<ul>
<li>Remove support for Python 2 (<a href="https://github.com/Cantera/cantera/pull/560">#560</a>, <a href="https://github.com/Cantera/cantera/pull/611">#611</a>)</li>
<li>Update physical constants based on 2018 CODATA values, and atomic weights to 2018 IUPAC/CIAAW values (<a href="https://github.com/Cantera/cantera/pull/653">#653</a>)</li>
<li>Deprecated some redundant or rarely-used classes and functions. See the deprecation lists for <a href="https://cantera.org/documentation/docs-2.5/doxygen/html/da/d58/deprecated.html">C++</a> and <a href="https://cantera.org/documentation/docs-2.5/sphinx/html/search.html?q=deprecated&check_keywords=yes&area=default">Python / Matlab / Input files</a>. (<a href="https://github.com/Cantera/cantera/pull/580">#580</a>, <a href="https://github.com/Cantera/cantera/pull/588">#588</a>, <a href="https://github.com/Cantera/cantera/pull/645">#645</a>, <a href="https://github.com/Cantera/cantera/pull/643">#643</a>, <a href="https://github.com/Cantera/cantera/pull/660">#660</a>, <a href="https://github.com/Cantera/cantera/pull/733">#733</a>, <a href="https://github.com/Cantera/cantera/pull/735">#735</a>, <a href="https://github.com/Cantera/cantera/pull/762">#762</a>, <a href="https://github.com/Cantera/cantera/pull/787">#787</a>, <a href="https://github.com/Cantera/cantera/pull/790">#790</a>, <a href="https://github.com/Cantera/cantera/pull/806">#806</a>, <a href="https://github.com/Cantera/cantera/pull/815">#815</a>, <a href="https://github.com/Cantera/cantera/pull/864">#864</a>, <a href="https://github.com/cantera/cantera/commit/35be561d99c4ee8f544db4016849d94bf26b4df6"><code>35be561</code></a>, <a href="https://github.com/cantera/cantera/commit/27d9b6413a6b12a84947db72658c1785e8c1393f"><code>27d9b64</code></a>)</li>
<li>Build and test the sample programs / scripts as part of the CI process (<a href="https://github.com/cantera/cantera/commit/1ec9ce2c01da81479952dcc12140634d9bd4d9ff"><code>1ec9ce2</code></a>, <a href="https://github.com/Cantera/cantera/pull/649">#649</a>, <a href="https://github.com/Cantera/cantera/pull/776">#776</a>, <a href="https://github.com/Cantera/cantera/pull/874">#874</a>, <a href="https://github.com/Cantera/cantera/pull/883">#883</a>, <a href="https://github.com/Cantera/cantera/pull/905">#905</a>, <a href="https://github.com/Cantera/cantera/pull/923">#923</a>, <a href="https://github.com/Cantera/cantera/pull/927">#927</a>)</li>
<li>Improve handling of phases where the intrinsic state variables are not temperature and density (<a href="https://github.com/Cantera/cantera/pull/720">#720</a>)</li>
<li>Improve detection and handling of errors in Chemkin input files (<a href="https://github.com/Cantera/cantera/pull/585">#585</a>, <a href="https://github.com/cantera/cantera/commit/b2acc43a813fd755a4b60bca87006dc7a72a74a0"><code>b2acc43</code></a>, <a href="https://github.com/cantera/cantera/commit/4f4a2bd07162a67ca96dcc9f514dbab29beedcfe"><code>4f4a2bd</code></a>, <a href="https://github.com/cantera/cantera/commit/d04fd8cc39cb9982aafe7cac28b58174b5fd6a81"><code>d04fd8c</code></a>)</li>
<li>Consolidate and report all errors when adding reactions, instead of just failing on the first one (<a href="https://github.com/Cantera/cantera/pull/903">#903</a>, <a href="https://github.com/Cantera/cantera/pull/946">#946</a>)</li>
<li>Use 'Q' instead of 'X' for the quality (vapor fraction) of two-phase mixtures in Python (<a href="https://github.com/Cantera/cantera/pull/719">#719</a>)</li>
<li>Always use temperature of the "reacting" phase for interface kinetics (<a href="https://github.com/cantera/cantera/commit/6c82b61c3d8b6738a8a9edb5c062fa3c50423d96"><code>6c82b61</code></a>)</li>
<li>Make interface for setting parameters for Valves and PressureControllers more intuitive (<a href="https://github.com/Cantera/cantera/pull/667">#667</a>, <a href="https://github.com/Cantera/cantera/pull/682">#682</a>)</li>
<li>Add N2 to h2o2.yaml (<a href="https://github.com/Cantera/cantera/pull/959">#959</a>)</li>
<li>Make CVODES integrator 'max_time_step' a property in the Python module (<a href="https://github.com/Cantera/cantera/pull/731">#731</a>)</li>
<li>Switch CI to GitHub Actions (<a href="https://github.com/Cantera/cantera/pull/775">#775</a>, <a href="https://github.com/Cantera/cantera/pull/884">#884</a>, <a href="https://github.com/Cantera/cantera/pull/889">#889</a>, <a href="https://github.com/Cantera/cantera/pull/957">#957</a>)</li>
<li>Use experimentally-derived O2/O2- collision integral in ionized flames (<a href="https://github.com/Cantera/cantera/pull/552">#552</a>)</li>
<li>Consistently use CanteraError in Python examples (<a href="https://github.com/Cantera/cantera/pull/596">#596</a>, <a href="https://github.com/cantera/cantera/commit/05eaa0a5e4d0c73c5827f7f2c9bbd090d68e8c30"><code>05eaa0a</code></a>)</li>
<li>Add option to use case-sensitive species names (<a href="https://github.com/Cantera/cantera/pull/689">#689</a>)</li>
<li>Treat deprecation warnings issued from Python and C++ consistently (<a href="https://github.com/Cantera/cantera/pull/796">#796</a>)</li>
<li>Improve sample build scripts on maCOS (<a href="https://github.com/Cantera/cantera/pull/612">#612</a>)</li>
<li>Updated the 'diamond_cvd.py' example to include plotting the output (<a href="https://github.com/Cantera/cantera/pull/630">#630</a>)</li>
<li>Make GRI-3.0 mechanisms consistent with latest online version (<a href="https://github.com/Cantera/cantera/pull/718">#718</a>)</li>
<li>Follow Python naming convention for arguments to ThermoPhase.equilibrate (<a href="https://github.com/Cantera/cantera/pull/684">#684</a>)</li>
<li>Remove unused Chemkin input files from the source distribution (<a href="https://github.com/Cantera/cantera/pull/799">#799</a>)</li>
<li>Move heat_release_rate method to Python Kinetics class (<a href="https://github.com/Cantera/cantera/pull/810">#810</a>)</li>
<li>Automatically add 'negative_A' option for third body reactions when converting from Chemkin input (<a href="https://github.com/Cantera/cantera/pull/822">#822</a>)</li>
<li>Allow negative pre-exponential factor for falloff reactions (<a href="https://github.com/Cantera/cantera/pull/868">#868</a>)</li>
<li>Search current working directory before built-in data directories when using Python (<a href="https://github.com/Cantera/cantera/pull/792">#792</a>)</li>
<li>Check for additional invalid string-to-double conversions when parsing composition strings (<a href="https://github.com/cantera/cantera/commit/84535483f9ba768c72196fccf2e9ac2c1ee9d0dd"><code>8453548</code></a>)</li>
<li>The default branch for the Cantera Git repository is now named 'main' (<a href="https://github.com/Cantera/cantera/pull/890">#890</a>)</li>
<li>Include more significant digits for Redlich-Kwong coefficients when converting from CTI to XML (<a href="https://github.com/cantera/cantera/commit/ec7f779434d705ea5097abdc88a723e1dd4c96e8"><code>ec7f779</code></a>)</li>
</ul>

<h2>Bugs fixed:</h2>
<ul>
<li>Fixed various compilation issues on specific platforms and with certain SCons/compiler options (<a href="https://github.com/Cantera/cantera/pull/561">#561</a>, <a href="https://github.com/Cantera/cantera/pull/572">#572</a>, <a href="https://github.com/Cantera/cantera/pull/601">#601</a>, <a href="https://github.com/Cantera/cantera/pull/648">#648</a>, <a href="https://github.com/Cantera/cantera/pull/661">#661</a>, <a href="https://github.com/Cantera/cantera/pull/674">#674</a>, <a href="https://github.com/Cantera/cantera/pull/676">#676</a>, <a href="https://github.com/Cantera/cantera/pull/685">#685</a>, <a href="https://github.com/Cantera/cantera/pull/742">#742</a>, <a href="https://github.com/Cantera/cantera/pull/765">#765</a>, <a href="https://github.com/Cantera/cantera/pull/779">#779</a>, <a href="https://github.com/Cantera/cantera/pull/803">#803</a>, <a href="https://github.com/Cantera/cantera/pull/824">#824, <a href="https://github.com/Cantera/cantera/pull/879">#879</a>, <a href="https://github.com/Cantera/cantera/pull/891">#891</a>, <a href="https://github.com/Cantera/cantera/pull/918">#918</a>, <a href="https://github.com/Cantera/cantera/pull/960">#960</a>, <a href="https://github.com/Cantera/cantera/pull/962">#962</a>, <a href="https://github.com/Cantera/cantera/pull/973">#973</a>, <a href="https://github.com/cantera/cantera/commit/46b7cf180a9c10bf27330de804353c9ded792b7f"><code>46b7cf1</code></a>)</li>
<li>Fix handling of local quantity units rate for Chebyshev rate constants when converting Chemkin input files (<a href="https://github.com/Cantera/cantera/pull/600">#600</a>)</li>
<li>Fix setting of Soret and multicomponent diffusion options after exceptions when using the "auto" option to Sim1D.solve (<a href="https://github.com/Cantera/cantera/pull/631">#631</a>)</li>
<li>Disable free flame domain width check when auto=False (<a href="https://github.com/Cantera/cantera/pull/690">#690</a>)</li>
<li>Allow setting beta = 0 for electrochemical reactions (<a href="https://github.com/Cantera/cantera/pull/955">#955</a>)</li>
<li>Fix Redlich-Kwong phase to not use the element potential equilibrium solver (<a href="https://github.com/Cantera/cantera/pull/898">#898</a>)</li>
<li>Fix erroneously-rounded transport coefficients in input files derived from GRI 3.0 (<a href="https://github.com/Cantera/cantera/pull/598">#598</a>)</li>
<li>Use correct phase state after Reactor mass flow rate evaluation (<a href="https://github.com/Cantera/cantera/pull/651">#651</a>)</li>
<li>Avoid NaN in entropy with small negative mass fractions (<a href="https://github.com/Cantera/cantera/pull/686">#686</a>)</li>
<li>Fix conversion of Chemkin input files with surface reactions with explicit reverse rates (<a href="https://github.com/Cantera/cantera/pull/754">#754</a>)</li>
<li>Fix conditional property updates in IonGasTransport (<a href="https://github.com/Cantera/cantera/pull/568">#568</a>)</li>
<li>Fix Chebyshev rate evaluation with only 1 point in T or P (<a href="https://github.com/Cantera/cantera/pull/706">#706</a>)</li>
<li>Check for non-existent species in reaction orders when adding reactions (<a href="https://github.com/cantera/cantera/commit/e4362d37e7cf2d527a14c6202868b5ffd76f2436"><code>e4362d3</code></a>)</li>
<li>Fix various edge cases for saturated PureFluid states (<a href="https://github.com/Cantera/cantera/pull/907">#907</a>)</li>
<li>Fix comparisons of non-numeric text in test_problems (<a href="https://github.com/Cantera/cantera/pull/785">#785</a>)</li>
<li>Prevent overwriting of pre-existing extra SolutionArray columns (<a href="https://github.com/Cantera/cantera/pull/820">#820</a>)</li>
<li>Fix slicing of SolutionArray (<a href="https://github.com/Cantera/cantera/pull/816">#816</a>, <a href="https://github.com/Cantera/cantera/pull/837">#837</a>)</li>
<li>Prevent erroneous creation of standalone Kinetics and Transport objects in Python (<a href="https://github.com/Cantera/cantera/pull/845">#845</a>)</li>
<li>Ensure that the mass flow rate returned by FlowDevice objects is correct after a call to ReactorNet::advance (<a href="https://github.com/Cantera/cantera/pull/886">#886</a>)</li>
<li>Fix indexed assignment of 'extra' columns in SolutionArray (<a href="https://github.com/Cantera/cantera/pull/838">#838</a>)</li>
<li>Fix handling of reaction units settings not on last line when convert Chemkin input files (<a href="https://github.com/cantera/cantera/commit/540777c32b57d99c61d0bf1e2cc825353be4846b"><code>540777c</code></a>)</li>
<li>Fix over-zealous detection of section 'end' labels when converting Chemkin input files (<a href="https://github.com/cantera/cantera/commit/e3424d8ed49f5f7611bc94933109292d32b732ec"><code>e3424d8</code></a>)</li>
<li>Fix building and installing the minimal Python package (<a href="https://github.com/Cantera/cantera/pull/928">#928</a>, <a href="https://github.com/Cantera/cantera/pull/974">#974</a>)</li>
<li>Check for a valid species index in ThermoPhase::species() (<a href="https://github.com/Cantera/cantera/pull/949">#949</a>)</li>
<li>Fix some corner cases in Sim1D::setFixedTemperature (<a href="https://github.com/Cantera/cantera/pull/936">#936</a>)</li>
<li>Retain user-specified products in counterflow premixed flame when using "auto" option (<a href="https://github.com/cantera/cantera/commit/b633544477facbb9f4390b380a2e7edefac79010"><code>b633544</code></a>)</li>
<li>Fix refinement check in ic_engine.py example (<a href="https://github.com/cantera/cantera/commit/d9b95b2efbe6c512f00f72fe2e0bf4fda76ba7e6"><code>d9b95b2</code></a>)</li>
<li>Fix issues with Blasius BVP example, and install it with other C++ samples (<a href="https://github.com/cantera/cantera/commit/dc09040274370149c6dafb05e126e875e0db6549"><code>dc09040</code></a>, <a href="https://github.com/cantera/cantera/commit/600580ead4906339fee0bae6a80356ec5d3a4191"><code>600580e</code></a>, <a href="https://github.com/cantera/cantera/commit/c26db356e3523c89878e8a6f5b5cd5d64dc32b73"><code>c26db35</code></a>, <a href="https://github.com/cantera/cantera/commit/b9a5913af01cb316734f3742d111614fc0a957b1"><code>b9a5913</code></a>, <a href="https://github.com/cantera/cantera/commit/22efbe25dc97c2e42960c7cf09335ca546ec8ef5"><code>22efbe2</code></a>, <a href="https://github.com/cantera/cantera/commit/8c213da93226859e741ac108333f1b08c4db7b24"><code>8c213da</code></a>)</li>
</ul>

<h2>Documentation updates:</h2>
<ul>
<li>Fix errors in equations (<a href="https://github.com/Cantera/cantera/pull/557">#557, <a href="https://github.com/Cantera/cantera/pull/970">#970</a>, <a href="https://github.com/cantera/cantera/commit/3ff5d87b815eb6c299745954947ff566e55066cc"><code>3ff5d87</code></a>, <a href="https://github.com/cantera/cantera/commit/c1d721dc94b4f5f8dedc47a4d8066bb24d761599"><code>c1d721d</code></a>)</li>
<li>Improve "offline" builds of API documentation (<a href="https://github.com/Cantera/cantera/pull/562">#562</a>)</li>
<li>Document required versions of Cantera and dependencies for Python examples (<a href="https://github.com/Cantera/cantera/pull/729">#729</a>, <a href="https://github.com/Cantera/cantera/pull/756">#756</a>)</li>
<li>Update AUTHORS list to include authors from all Cantera organization repos (<a href="https://github.com/Cantera/cantera/pull/573">#573</a>)</li>
<li>Fix various typos and other issues (<a href="https://github.com/Cantera/cantera/pull/591">#591</a>, <a href="https://github.com/Cantera/cantera/pull/627">#627</a>, <a href="https://github.com/Cantera/cantera/pull/636">#636</a>, <a href="https://github.com/Cantera/cantera/pull/673">#673</a>, <a href="https://github.com/Cantera/cantera/pull/709">#709</a>, <a href="https://github.com/Cantera/cantera/pull/726">#726</a>, <a href="https://github.com/Cantera/cantera/pull/744">#744</a>, <a href="https://github.com/Cantera/cantera/pull/770">#770</a>, <a href="https://github.com/Cantera/cantera/pull/771">#771</a>, <a href="https://github.com/Cantera/cantera/pull/781">#781</a>, <a href="https://github.com/Cantera/cantera/pull/790">#790</a>, <a href="https://github.com/Cantera/cantera/pull/793">#793</a>, <a href="https://github.com/Cantera/cantera/pull/939">#939</a>, <a href="https://github.com/cantera/cantera/commit/50997a165119ccb997206e4738750621510bbd79"><code>50997a1</code></a>, <a href="https://github.com/cantera/cantera/commit/9f5dfbdb1273c05d176c58ab62fe7dbb12d24a94"><code>9f5dfbd</code></a>, <a href="https://github.com/cantera/cantera/commit/442433ad3738ecf17052811bd5751d77666b558b"><code>442433a</code></a>, <a href="https://github.com/Cantera/cantera/pull/975">#975</a>, <a href="https://github.com/Cantera/cantera/pull/976">#976</a>)</li>
</ul>
</details>

* `ctml2yaml`
* `cti2yaml`
* `ck2yaml`

You can use these scripts in the same way that the old `ck2cti` script was used. All users are encouraged to switch their input files to the new format.

This release was made possible by the following contributors: Dave Holland, [12Chao](https://github.com/12Chao), [BangShiuh](https://github.com/BangShiuh), [CyberDrudge](https://github.com/CyberDrudge), [ThanasisMattas](https://github.com/ThanasisMattas), [agarwalrounak](https://github.com/agarwalrounak), [arghdos](https://github.com/arghdos), [band-a-prend](https://github.com/band-a-prend), [bryanwweber](https://github.com/bryanwweber), [decaluwe](https://github.com/decaluwe), [g3bk47](https://github.com/g3bk47), [ischoegl](https://github.com/ischoegl), [jsantner](https://github.com/jsantner), [kyleniemeyer](https://github.com/kyleniemeyer), [lavdwall](https://github.com/lavdwall), [lionkey](https://github.com/lionkey), [manikmayur](https://github.com/manikmayur), [mgashwinkumar](https://github.com/mgashwinkumar), [paulblum](https://github.com/paulblum), [rwest](https://github.com/rwest), [sameshl](https://github.com/sameshl), [sin-ha](https://github.com/sin-ha), [speth](https://github.com/speth), [spinnau](https://github.com/spinnau), [tsikes](https://github.com/tsikes), [wbessler](https://github.com/wbessler), [korffdm](https://github.com/korffdm)

The Cantera development team is pleased to announce the general availability of the first beta for the next release of Cantera, v2.5.0. There have been almost 900 commits to Cantera since the last version, 2.4.0, which was released in August 2018. We have closed or merged more than [200 pull requests](https://github.com/Cantera/cantera/pulls?q=is%3Apr+is%3Aclosed+updated%3A%3E%3D2018-08-24) and [100 issues](https://github.com/Cantera/cantera/issues?q=is%3Aissue+is%3Aclosed+updated%3A%3E%3D2018-08-24). The complete list of changes can be found on the Cantera Wiki page: https://github.com/Cantera/cantera/wiki/Complete-git-log-since-2.4.0

Bugs fixed

- Fix inconstencies and bugs in several `ThermoPhase` derived classes, including `PDSS_IdealGas`, `IonsFromNeutralVPSSTP`, `PDSS_IonsFromNeutral`, `PDSS_HKFT`, `LatticePhase`, `PDSS_SSVol`, `ConstDensityThermo`, and `PureFluidPhase`
- Preserve constant property pair when multiplying `Quantity` objects
- Fix using pure fluids in reactors
- Add temperature dependence of rotational relaxation in transport calculations
- Disable linking to external SUNDIALS libraries when building the Matlab toolbox

Changes to existing capabilities

- Allow instantiation of ThermoPhase derived classes without XML
- `set_equivalence_ratio` now supports sulfur oxidation
- Make all complex object types (ThermoPhase, Kinetics, Transport, Reactor, Domain1D, etc.) objects non-copyable
- Deprecate `FreeFlow` and `AxiStagnFlow` classes by moving the relevant functions into the `StFlow` class
- Allow `convertMech` function to be called multiple times
- Remove the requirement for users to have Boost headers installed when building against the Cantera library
- Change the options to build the Python interface, since SCons can be run by Python 3
- Update GTest, fmtlib, SUNDIALS, and Eigen submodule versions

Additions

- Add ion gas transport model, and `IonFlow` and `BurnerIonFlame` flame classes
- Add C++ OpenMP, Non-Ideal Shock Tube, PSR/WSR, and time-dependent mass flow rate examples
- Add class `AnyMap`
- Allow negative reaction orders
- Add unity Lewis number transport model
- Add electron to the built-in elements
- Add `get_equivalence_ratio` function

<details>
<summary><strong>Click here to see the complete changelog</strong></summary>

Full Changelog

Bugs fixed

Thermo/Species/Elements
- Fix issues parsing composition strings with mixtures of commas, colons, and spaces (3f6f580)
- Fix setting mass/mole fractions of phases with only a single species (ed8de04)
- Fix reference state calculations (38d291c, 7b529ac)
- Fix test failures due to inconsistent species addition order (11a0727, 433)
- Fix errors in entropy calculation in `PDSS_IdealGas` (dfb32f0)
- Fix and test creation of `IonsFromNeutralVPSSTP` objects (3a11938)
- Fix inconsistentices in `PDSS_IonsFromNeutral` (ff46dc9)
- Fix `PDSS_HKFT` initialization when only one property is given (2c3512c)
- Fix default molar volume in `LatticePhase` (f3ba29f)
- Setting the composition with an empty array raises an exception (8a4142d)
- Fix implementation and documentation of `PDSS_SSVol` (ee663c9, a19b2bd, 286217d, be8e51d)
- Fix definition of `ConstDensityThermo::standardConcentration` (89fded3, 458, 490)
- Preserve constant property pair when multiplying `Quantity` objects (c9b0bce)
- Fix `PureFluidPhase` state data consistency (fb68cae, 0417d31)

Kinetics
- Validate balance of surface sites for interface reactions (ac53371, 412)
- Reactions which are declared as duplicate but do not have the corresponding duplicate reaction are errors (0fd2f7c, 2678b57, 389)
- Fix use of `'scale'` and `'OneWayFlow'` options in `ReactonPathDiagram`s (0d982c8, 0249ce8, 378, 424)
- Fix how species contributions to reaction paths are handled (3093e6e, 5a0fb57, 092e007, 377, 424)
- Preserve pressure units in `PLOG` reactions when converting from Chemkin to CTI format (7b7aea2, a02753a, 435)
- Fix style arguments for reaction path diagrams (b41038f, 463)
- Fix duplicate reaction checking (513b432, 4c489c1, 468)
- Fix failures due to tolerances in some kinetics tests (67aa9eb)

Transport
- Fixes to enable `CK_mix` and `CK_multi` mode flags (35aa8be, 435f286, 1b60513)
- Add temperature dependence of rotational relaxation (e79cf6f, 547)

0-D Reactors
- Fix using pure fluids in reactors (2ac8a0e, deeaaed, 475, 487)
- Check that contents are Solution objects not Mixtures (a22db9f)

1-D Flames
- Fix handling of domain boundary conditions when the energy equation is not solved (52dbe8c)
- Fix handling of Soret diffusion enabling/disabling with respect to mixture-averaged diffusion approximation (a03afbd, 4bd5e92, fde5051, 511)

CTI/Input files
- Fix file size limit when converting CTI to CTML (0a1257d, 416, 430)
- Fix for reactions with pathologically named third bodies (55a8910, 6d591b8, 44b24ca, 460)
- `ctml_writer` is more tolerant of non-ASCII characters (0c0a38d)
- Fix incorrect entry in `nasathermo.dat` (3933a94, 491)
- Fix writing surface reactions to the CTI file when there are no gas-phase reactions (552ba97)
- Fix over-zealous detection of new input file sections (f47e98a)
- Detect badly-formatted values of the 4th Troe coefficient (bde6e05)
- Suppress some output when `quiet=True` (70016b9)
- Fix duplicate key check in parseCompString (d091617, 525)
- Fix spurious unexpected output warnings (fd57936)

Examples
- Fix errors and empty figures in IC engine example (6f564e6, 0d01d03)
- Remove extraneous arguments in Matlab example scripts (a31b7d1)
- Remove or fix broken Matlab examples (536158b, 987a247)

Other
- Add explicit dependencies on the `scons build` step for `scons test` and `scons install` (70e1063, 432)
- Fix reproducibility of `add_species_sequential` test (11a0727, 433)
- Disable linking to external SUNDIALS libraries when building the Matlab toolbox (c125878, 431, 456)
- Switch SourceForge links in the docs to point to GitHub (d920f2e, 442, 455)
- Fix typos in documentation (05809bb, fec6c34, 35ac1ac, af4ccae, 449)
- Easier debugging of NumPy import error messages during build (3f69f6a)
- Use Trusty Tahr and system Python 3 on TravisCI Linux builds (9e5da87, 45891a2)
- Fix parallel builds of the Matlab toolbox (8312396, 483)
- Remove outdated MacPorts installation instructions (46f8ef5, 496)
- Fix wrong environment variable MATLAB_PATH -> MATLABPATH (d86a7c1, 501)
- Fix broken links in README, clarify PR template, add Gitter, add badges (e052a44, 8de267f, de3ec3d, 0120f2f, 505, 506, 513)
- Fix installing dependencies on Appveyor (39c4103, 0b8f028, b1a010e, 517, 529)
- Add update of git submodules to code checkout instructions (66ba4b5)
- Remove blank documentation page (84acdb1, 518)
- Fix notation for mixture-averaged diffusion coefficient (df6ecb1)
- Fix compilier warning about `m_Faraday_dim` (55490de)
- Fix catching exceptions when checking git commit during build (3fac5f2, c830537)
- Fix display of information from errors in Python callbacks (d3f49e7)
- Clean the correct folder after building the minimal Python interface (ff91457)
- Fix building MSI for Python 3.7 module (af51a61)

Changes to existing capabilities

Thermo/Species/Elements
- PDSS objects store their own data (50ed3f2)
- Remove `VPSSMgr` and merge into `VPStandardStateTP` (b39537b, 428)
- Simplify aqueous phase creation in `VPStandardStateTP` (3ea2a6c)
- Allow instantiation of ThermoPhase derived classes without XML (86dca05, 507a3a9, 19c17d1, db1f1af, 5efea12, 3c771de, b033d44, 31d54c3, 95a52b2, f8ef4a8, a6ac446, bfdc2b9, f69ef44, d744bd9, 3676672, aa02d24, e3afaf5, 3790115, 4c630fc, a520f78)
- Clean up and test `RedlichKwongMFTP` implementation and remove broken "sanity checks" (ecbd819, dd521de, f9d5f16, 267, 436, 438)
- Move common PDSS functions into the the `PDSS_Nondimensional` class (574462f)
- Remove unused thermodynamics models from `ThermoFactory` (6154e1b)
- Deprecate several unused/untested classes. See the [deprecation list](https://cantera.org/documentation/docs-2.4/doxygen/html/da/d58/deprecated.html) for details. (2b73fe2, 6d22be2, #267)
- Remove unimplemented options from `DebyeHuckel` (afafa34)
- Charge transfer reactions can be set for `surface_reaction`s, not just `edge_reaction`s (51f419f, 439)
- Remove unused members from some thermo classes (4818c87, 6bfd82e, 90d18dd, c85ba58, cfc3b72, 6ca7820, d07908f, 4b69c7f, 572af61)
- Store several class properties as `shared_ptr`s (04f1097, 4856d13)
- Remove debug exception from Phase::entropyElement298 (d433824, 467)
- Explicitly assume that the solvent species is always the first species in the phase (e33fe69)
- Move implementation of `HMWSoln` to a single file (e9f08fc)
- Try to look up standard entropy when adding undefined elements (0ca788b)
- Always use `PDSS_ConstVol` for constant volume standard state and remove the implementation from `PDSS_SSVol` (822cdc7)
- Make adding undefined elements the default behavior (d035557)
- `set_equivalence_ratio` now supports sulfur oxidation (48eaedb, acbd65d, aac8eb9, 474)
- Relax warning threshold for heat capacity discontinuities (a68c048)

Equilibrium Solvers
- Various clean ups, refactoring, and simplifications to the VCS solver (ee323bb, 08726b0, da801f4, 8522095, bba0d8e, 1eebd3e, da3ba35, 4e53c89, 7eb939d, 739d4e4)
- Improve control of logging in the ChemEquil solver (5b4a977)
- Don't use saved element potentials as an initial guess and deprecate getter/setter methods (74167cc, 3c978cd, 538)

Transport
- Allow construction of Transport derived classes without XML (4b5af64, 7020fa7)
- Move `simpleTransport` test to GTest suite (4934079)

0-D Reactors
- Make all reactor-related objects non-copyable (d9418bb)

1-D Flames
- Make all 1-D-related objects non-copyable (279c5c8)
- Deprecate `FreeFlow` and `AxiStagnFlow` classes by moving the relevant functions into the `StFlow` class (c1067aa, 3ade333, a54ab2f, 546, 548)

CTI/XML/Input Files
- Make searches for child nodes case insensitive (1bd950f)
- Improve error messages for invalid (floating point) geometry flags (6bf74d1, 446, 454)

Examples/Samples
- Remove verbose output from f77 demo wrapper (172e9ff)

Documentation
- Note requirement to use `modifySpecies` and `modifyReaction` (4b4128a, 394, 542)
- Clarify the values returned by `getFwdRateConstants` (831b92d)
- Move most content from the old documentation to the new website (7b6d04c, cc9c8e5, 71072c4, e81cac9, e7f346c, 7a69386, d57f1d1, b68a87d, 21db5d8, 3052701, 2a7aed8, e8d28b0, dbc3df1, 2f3a012, 9670c5d, 3fae1c1, 4ea9d35, 5494636, d225203, c28bc02, d33e67c, 7e1b6a1, 3384041, 0d55977, b84d3e3, 053267e, 1864e8f, 5f556ac, 045f3d3, 1ca6c5e, 323c737, 544)

Other
- Move MixMaster into a separate repository (886d7b7)
- Propagation of environment variables in SCons is more sensible (e5edc31, 3c82c3a, eae9250, 66998a5)
- Remove deprecated code (7673f7c, 3accd41)
- Print error messages from and pass flags to GTest (fca22d9, 461b63e)
- Remove the requirement for clients to have Boost headers installed when building against the Cantera library (713b9cc, f8d1832, 686250e, 87a7deb, 83ffd84, 480)
- Update to GTest 1.8.0 (60d2075, 482)
- Remove `HAS_NO_PYTHON` configuration variable (16fd183, 483)
- Change the options to build the Python interface, since SCons can be run by Python 3 (94ea9b5, 2bc4d09, 6ca67b4, 11943bb, 7054a7b, f824b20, 43b42e9, c233ddc, 9f4590b, 9c9ee9e, 5d599bb, 4e6af27, 3e39a0b, 483, 486, 488)
- Check for 3to2 during build by importing the library, rather than running a script (77ee76c, 483)
- Use std::sort to eliminate need for vcs_optMax (07eed36)
- Google Test suite can be disabled entirely (fb4a36b, 9bad354, 333d388, 535)
- Improve behavior of Matlab test suite (bdaabc0, 677efd8, b5b542d)

Additions

Thermo/Species/Elements
- Allow synonyms for Factory model names (c28ca48)
- Add electron to the built-in elements (974bbc7, 443)
- Identify unspecified electrochemical reactions (04be988, 452)
- Make activity coefficients and activities available (a5b0bdf)
- Add regression tests for some thermo classes (338b216)
- Create a default constructor for PDSS objects and avoid unnecessary arguments in the initializers (04cac2b)
- Show values in `setDensity`/`setTemperature` exceptions (ebc478f)
- Add Cython function to access species viscosity (cc93ce6, 527)
- Add `get_equivalence_ratio` function (a9ad75e, 521)
- Add `newSubstance` method to create pure fluid objects by name (62c67e4)
- Allow `surface_reaction`s (not just `edge_reaction`s) to be charge transfer reactions (51f419f, 439)

Transport
- Add unity Lewis number transport model (d38d9da, 29a3c19, 3c3ef10, d4492f3, a1c12b4, 510)
- Add ion gas transport model (b7e32e4, 3a0f46e, eeb27d8, f7852ad, fa9b937, 1245a69, 5c783c7, 539)

1-D Flames
- Add access to current solution resdiuals (6a52908)
- Allow user to pass the locations where temperature is set during flame initialization (2a38b0a, 447)
- Add ability to simulate ionized flames using the `IonFlow` class and the `BurnerIonFlame` and `(3b12c6d, e2f718c, 9dd0134, 6b6d758, 1057d20, 1be8374, a8cbfd2, 2472e08, a99004d, 24940ae, c3ba264, a5762ea, ac8612f, 441, 471, 546, 548)
- Add function to get the refine criteria used in a flame (bce4210, 4b44c66, c88ddce, 469)
- Add a more general `CounterFlowDiffusionFlame` to Matlab, replacing `npflame_init` (43bd96b, c092484, 450)
- Allow access to and disabling of callbacks for 1-D problems (4b35275, 7a314d3, 489)
- Automatically detect when the domain width is too narrow or the flame has blown off the burner (dfd4b7e, 7eb4eaa, 4911539, 489)
- Add `BurnerIonFlame` class (2527869, 5082a21, ee633f3, 1662498, 548)

CTI/Input files
- Allow negative reaction orders (8f02c77, 4771874, 501b5fd, 485)
- Add support for parsing species with specific site occupancies (89bca5f, 444)
- Improve error message reporting during failed ck2cti conversions (4b5a37a, 9c3b500, 4affcd1, 411be3e, 497)
- Allow `convertMech` function to be called multiple times (277aa0b, 528, 536)

Other
- Add methods for getting the git commit (8e89bbb, 7979a2b)
- Add class `AnyMap` (56022e8, 9c084d5, 7fab7f3, 443)
- Add compatiblity with Cython >=0.26 (8d953a9, 465, 467)
- Add compatibility with fmt 4.0.0 (ea69a01, 470)
- Building now supports SCons 3.0.0 and Python 3 runnning SCons (7d0bc71, 684262e, 477, 478, 481)
- Allow building and testing with msvc-12.0 (e921cb8, 6844e52, 479)
- Add `setup_cantera.csh` for use with csh/tcsh (4a4886f, 453)
- Add conda GCC compilers to the check for C compilers during building (07409de, 486)
- Many documentation updates related to Cantera joining NumFOCUS (e846505, e6b4761, af4a78d, ec5aecd, 419a09c, 581cfb7, 8caf5e5, 977a1c7, 0d20b50, c78a11b, 2abc57e, 05fa4df, 8195403, 1a394a3, c29fbc8, 66597b7, a0ac2b0, 502)
- Add support for SUNDIALS 3.0.0 and 3.1.0 (50a3fec, 9c50f75, 82c959d, 322b1fc, 503)
- Upgrade Eigen submodule to 3.3.4 (20f891f)
- Add links to old versions of the documentation (b26dc65)
- Upgrade `fmtlib` submodule to 5.0.0 (6b3c912, 99d4972, 3be3f7d, e42b952, 51d0d43, 309871a, dab7390, 540)

Examples/Samples
- Add C++ OpenMP example (78d5809)
- Add NonIdealShockTube example (2a601c1, e78aac7, 26216e9, 473, 483)
- Add example of PSR/WSR that replaces `combustor.py` (dc5ec06, 550)
- Add example of using a time-dependent mass flow into a reactor (2f67c99, 550)
</details>

Highlights are listed here. See the [full changelog](https://github.com/Cantera/cantera/pull/399#issuecomment-263736973) for more.
- Add ability to modify species data for existing Phase objects
- Make species names case-preserving instead of case-sensitive, and allow colons in species names
- Add option for Motz & Wise correction to sticking reactions
- Implement enthalpy of formation sensitivity analysis for reactor networks
- Implement the Cython function `advance_to_steady_state` for reactor networks
- Eliminate most known 1D flame solver failures by improving Jacobian evaluation, and using better default initial grids and initial guesses
- Introduce 'auto' option to Sim1D.solve to automatically try multiple initial grids
- Generalize initial profile generation for diffusion flames for arbitrary fuel/oxidizer combinations
- Add general support for calculating adjoint sensitivities for 1D flames
- Add a Twin Premixed Counterflow Flame class and example
- Support conversion of surface mechanism files
- Provide better error message for problematic reaction and thermo entries when converting input files
- Add 'nonreactant_orders' option to allow non-reactant orders
- Allow adding species / reactions from Python
- Add new classes `Quantity` and `SolutionArray` to Python
- Make Python test suite runnable from an installed copy of the Python module
- Introduced Continuous Integration testing using Travis CI and AppVeyor
- Use Git submodules for Sundials, Eigen, Google Test, and libfmt if system versions are not installed
- Use Sundials and Eigen to eliminate the need for bundled LAPACK
- Added Conda build recipe and made binaries available through anaconda.org
- Add support for Sundials 2.7
- Deprecate unused classes, functions, arguments, and constants (see http://cantera.github.io/dev-docs/doxygen/html/deprecated.html for details)
- Add notices to documentation for classes with no tests or examples (see https://github.com/Cantera/cantera/issues/267)
- Make clib usable as a pure C (not C++) interface and add tests

- Maintenance release fixing issues identified since Cantera 2.2.0.
- Now includes Windows binaries for Python 3.5.