(sec-yaml-phases)= # Phase Definitions A `phase` is a mapping that contains definitions for the elements, species, and optionally reactions that can take place in that phase. The fields of a `phase` entry are: `name` : String identifier used for the phase. Required. `elements` : Specification for the elements present in the phase. This can be: - Omitted, in which case the standard elements will be added as needed by the species included in the phase. - A list of element symbols, which can be either defined in the `elements` section of the file or taken from the standard elements. - A list of single-key mappings of section names to lists of element symbols. These sections can be in the same file as the phase definition, or from another file if written as `file-path/sectionname`. If a relative path is specified, the directory containing the current file is searched first, followed by the Cantera data path. Standard elements can be included by referencing the fictitious section `default`. (sec-yaml-phase-species)= `species` : Specification for the species present in the phase. This can be: - a list of species that appear in the `species` section of the file. - The string `all`, to indicate that all species in the `species` section should be included. This is the default if no `species` entry is present. - A list of single-key mappings of section names to either the string `all` or a list of species names. These sections can be in the same file as the phase definition, or from another file if written as `file-path/sectionname`. If a relative path is specified, the directory containing the current file is searched first, followed by the Cantera data path. Species may be skipped depending on the setting of the `skip-undeclared-elements` option. `skip-undeclared-elements` : If set to `true`, do not add species that contain elements that are not explicitly included in the phase. The default is `false`, where the presence of such species is considered an error. Filtering of reactions is controlled by the `declared-species` option in the [](sec-yaml-phase-reactions) entry and the `skip-undeclared-third-bodies` flag. `skip-undeclared-third-bodies` : If set to `true`, ignore third body efficiencies for species that are not defined in the phase. The default is `false`, where the presence of such third body specifications is considered an error. (sec-yaml-phase-explicit-third-body-duplicates)= `explicit-third-body-duplicates` : Specifies how to handle three body reactions with an explicit collider that are duplicates of a three body reaction with the default collider `M`. This can be: - `warn`: Issue a warning about such reactions. This is the default. - `error`: Raise an exception if such reactions are found. - `mark-duplicate`: Mark the reactions as duplicates. Species production and consumption rates will reflect the sum of the rates. This option may correspond to the behavior of software packages that do not check for this kind of duplicate reaction. - `modify-efficiency`: Set the efficiency of the explicit third body to zero for the reaction that gives the rate for the default collider. This option is the most self-consistent but may not correspond to the intent of the mechanism's authors. :::{versionadded} 3.1 ::: `state` : A mapping specifying the thermodynamic state. See [](sec-yaml-setting-state). `adjacent-phases` : For interface phases, specification of adjacent phases that participate in reactions on the interface. This can be: - a list of phase names that appear in the `phases` section of the file. - A list of single-key mappings of section names to a list of phase names. These sections can be in the same file as the current phase definition, or from another file if written as `file-path/section-name`. If a relative path is specified, the directory containing the current file is searched first, followed by the Cantera data path. (sec-yaml-phase-thermo)= `thermo` : String specifying the phase thermodynamic model to be used. Supported model strings are: - [`binary-solution-tabulated`](sec-yaml-binary-solution-tabulated) - [`compound-lattice`](sec-yaml-compound-lattice) - [`coverage-dependent-surface`](sec-yaml-coverage-dependent-surface) - [`Debye-Huckel`](sec-yaml-Debye-Huckel) - [`edge`](sec-yaml-edge) - [`electron-cloud`](sec-yaml-electron-cloud) - [`fixed-stoichiometry`](sec-yaml-fixed-stoichiometry) - [`HMW-electrolyte`](sec-yaml-HMW-electrolyte) - [`ideal-gas`](sec-yaml-ideal-gas) - [`ideal-molal-solution`](sec-yaml-ideal-molal-solution) - [`ideal-condensed`](sec-yaml-ideal-condensed) - [`ideal-solution-VPSS`](sec-yaml-ideal-solution-VPSS) - [`ideal-surface`](sec-yaml-ideal-surface) - [`lattice`](sec-yaml-lattice) - [`liquid-water-IAPWS95`](sec-yaml-liquid-water-IAPWS95) - [`Margules`](sec-yaml-Margules) - [`Peng-Robinson`](sec-yaml-Peng-Robinson) - [`plasma`](sec-yaml-plasma) - [`pure-fluid`](sec-yaml-pure-fluid) - [`Redlich-Kister`](sec-yaml-Redlich-Kister) - [`Redlich-Kwong`](sec-yaml-Redlich-Kwong) (sec-yaml-phase-kinetics)= `kinetics` : String specifying the kinetics model to be used. Supported model strings are: - `none` - `bulk` ({ct}`details `) - `gas` (alias for `bulk`) - `surface` ({ct}`details `) - `edge` ({ct}`details `) (sec-yaml-phase-reactions)= `reactions` : Source of reactions to include in the phase, if a kinetics model has been specified. This can be: - The string `all`, which indicates that all reactions from the `reactions` section of the file should be included. This is the default if no `reactions` entry is present. - The string `declared-species`, which indicates that all reactions from the `reactions` section involving only species present in the phase should be included. - The string `none`, which indicates that no reactions should be added. This can be used if reactions will be added programmatically after the phase is constructed. - A list of sections from which to include reactions. These sections can be in the same file as the phase definition, or from another file if written as `file-path/sectionname`. If a relative path is specified, the directory containing the current file is searched first, followed by the Cantera data path. - A list of single-key mappings of section names to rules for adding reactions, where for each section name, that rule is either `all` or `declared-species` and is applied as described above. `Motz-Wise` : Boolean indicating whether the Motz-Wise correction should be applied to sticking reactions. Applicable only to interface phases. The default is `false`. The value set at the phase level may be overridden on individual reactions. (sec-yaml-phase-transport)= `transport` : String specifying the transport model to be used. Supported model strings are: - `none` - `high-pressure`: A model for high-pressure gas transport properties based on a method of corresponding states ({ct}`details `) - `ionized-gas`: A model implementing the Stockmayer-(n,6,4) model for transport of ions in a gas ({ct}`details `) - `mixture-averaged`: The mixture-averaged transport model for ideal gases ({ct}`details `) - `mixture-averaged-CK`: The mixture-averaged transport model for ideal gases, using polynomial fits corresponding to Chemkin-II ({ct}`details `) - `multicomponent`: The multicomponent transport model for ideal gases ({ct}`details `) - `multicomponent-CK`: The multicomponent transport model for ideal gases, using polynomial fits corresponding to Chemkin-II ({ct}`details `) - `unity-Lewis-number`: A transport model for ideal gases, where diffusion coefficients for all species are set so that the Lewis number is 1 ({ct}`details `) - `water`: A transport model for pure water applicable in both liquid and vapor phases ({ct}`details `) (sec-yaml-setting-state)= ## Setting the state The state of a `phase` can be set using two properties to set the thermodynamic state, plus the composition. The composition can be set using one of the following fields, depending on the phase type. The composition is specified as a mapping of species names to values. Where necessary, the values will be automatically normalized. - `mass-fractions` or `Y` - `mole-fractions` or `X` - `coverages` - `molalities` or `M` The thermodynamic state can be set using the following property pairs, with some exceptions for phases where setting that property pair is not implemented. All properties are on a per unit mass basis where relevant: - `T` and `P` - `T` and `D` - `T` and `V` - `H` and `P` - `U` and `V` - `S` and `V` - `S` and `P` - `S` and `T` - `P` and `V` - `U` and `P` - `V` and `H` - `T` and `H` - `S` and `H` - `D` and `P` The following synonyms are also implemented for use in any of the pairs: - `temperature`, `T` - `pressure`, `P` - `enthalpy`, `H` - `entropy`, `S` - `int-energy`, `internal-energy`, `U` - `specific-volume`, `V` - `density`, `D` (sec-yaml-phase-thermo-models)= ## Phase thermodynamic models (sec-yaml-binary-solution-tabulated)= ### `binary-solution-tabulated` A phase representing a binary solution where the excess enthalpy and entropy are interpolated between tabulated values as a function of mole fraction, as {ct}`described here `. Includes the fields of [](sec-yaml-ideal-condensed), plus: `tabulated-species` : The name of the species to which the tabulated enthalpy and entropy is added. `tabulated-thermo` : A mapping containing three (optionally four) lists of equal lengths: `mole-fractions` : A list of mole fraction values for the tabulated species. `enthalpy` : The extra molar enthalpy to be added to the tabulated species at these mole fractions. `entropy` : The extra molar entropy to be added to the tabulated species at these mole fractions. `molar-volume` : The molar volume of the phase at these mole fractions. This input is optional. ```yaml - name: graphite-anode thermo: binary-solution-tabulated species: ["Li[anode]", "V[anode]"] standard-concentration-basis: unity tabulated-species: Li[anode] units: {energy: J, quantity: mol, pressure: atm} tabulated-thermo: mole-fractions: [5.75000E-03, 1.25841E-01, 2.45932E-01, 3.66023E-01, 4.86114E-01, 6.06205E-01, 7.26295E-01] enthalpy: [-6.40692E+04, -9.69664E+03, -8.31339E+03, -7.69063E+03, -3.94568E+03, -2.01329E+03, -1.59649E+03] entropy: [3.05724E+01, 2.53501E+01, 1.27000E+01, 1.21865E+01, 1.70474E+01, 1.92980E+01, 1.92885E+01] state: {T: 300, P: 1, X: {"Li[anode]": 0.3, "V[anode]": 0.7}} ``` :::{versionadded} 2.5 ::: (sec-yaml-compound-lattice)= ### `compound-lattice` A phase that is comprised of a fixed additive combination of other lattice phases, as {ct}`described here `. Additional fields: `composition` : A mapping of component phase names to their relative stoichiometries. Example: ```yaml - name: Li7Si3_and_Interstitials(S) elements: [Li, Si] thermo: compound-lattice composition: {Li7Si3(s): 1.0, Li7Si3-interstitial: 1.0} ``` (sec-yaml-coverage-dependent-surface)= ### `coverage-dependent-surface` A coverage-dependent surface phase. That is, a surface phase where the enthalpy, entropy, and heat capacity of each species may depend on its coverage and the coverage of other species in the phase. Full details are {ct}`described here `. The majority of coverage dependency parameters are provided in the species entry as [described here](sec-yaml-species-coverage). Additional fields: `site-density` : The molar density of surface sites. `reference-state-coverage` : The reference state coverage denoting the low-coverage limit (ideal-surface) thermodynamic properties. Example: ```yaml - name: covdep thermo: coverage-dependent-surface species: [Pt, OC_Pt, CO2_Pt, C_Pt, O_Pt] state: T: 500.0 P: 1.01325e+05 coverages: {Pt: 0.5, OC_Pt: 0.5, CO2_Pt: 0.0, C_Pt: 0.0, O_Pt: 0.0} site-density: 2.72e-09 reference-state-coverage: 0.22 ``` :::{versionadded} 3.0 ::: (sec-yaml-debye-huckel)= ### `Debye-Huckel` A dilute liquid electrolyte which obeys the Debye-Hückel formulation for nonideality as {ct}`described here `. Additional parameters for this model are contained in the `activity-data` field: `activity-data` : The activity data field contains the following fields: `model` : One of `dilute-limit`, `B-dot-with-variable-a`, `B-dot-with-common-a`, `beta_ij`, or `Pitzer-with-beta_ij` `A_Debye` : The value of the Debye "A" parameter, or the string `variable` to use a calculation based on the water equation of state. Defaults to the constant value of 1.172576 kg^0.5/gmol^0.5, a nominal value for water at 298 K and 1 atm. `B_Debye` : The Debye "B" parameter. Defaults to 3.2864e+09 kg^0.5/gmol^0.5/m, a nominal value for water. `max-ionic-strength` : The maximum ionic strength `use-Helgeson-fixed-form` : Boolean, `true` or `false` `default-ionic-radius` : Ionic radius to use for species where the ionic radius has not been specified. `B-dot` : The value of B-dot. `beta` : List of mappings providing values of $\beta_{ij}$ for different species pairs. Each mapping contains a `species` key that contains a list of two species names, and a `beta` key that contains the corresponding value of $\beta_{ij}$. Example: ```yaml - name: debye-huckel-pitzer-beta_ij-IAPWS species: - water_IAPWS: [H2O(L)] - species_waterSolution: [Na+, Cl-, H+, OH-, NaCl(aq), NaOH(aq)] thermo: Debye-Huckel activity-data: model: Pitzer-with-beta_ij A_Debye: variable B_Debye: 3.28640E9 kg^0.5/gmol^0.5/m default-ionic-radius: 3.042843 angstrom max-ionic-strength: 3.0 beta: - species: [H+, Cl-] beta: 0.27 - species: [Na+, Cl-] beta: 0.15 - species: [Na+, OH-] beta: 0.06 state: T: 300.0 K P: 1.01325e+05 Pa molalities: {Na+: 3.0, Cl-: 3.0, H+: 1.0499e-08, OH-: 1.3765e-06, NaCl(aq): 0.98492, NaOH(aq): 3.8836e-06} ``` In addition, the Debye-Hückel model uses several species-specific properties which may be defined in the `Debye-Huckel` field of the *species* entry. These properties are: `ionic-radius` : Size of the species. `electrolyte-species-type` : One of `solvent`, `charged-species`, `weak-acid-associated`, `strong-acid-associated`, `polar-neutral`, or `nonpolar-neutral`. The type `solvent` is the default for the first species in the phase. The type `charged-species` is the default for species with a net charge. Otherwise, the default is and `nonpolar-neutral`. `weak-acid-charge` : Charge to use for species that can break apart into charged species. Example: ```yaml species: - name: NaCl(aq) composition: {Na: 1, Cl: 1} thermo: model: piecewise-Gibbs h0: -96.03E3 cal/mol dimensionless: true data: {298.15: -174.5057463, 333.15: -174.5057463} equation-of-state: model: constant-volume molar-volume: 1.3 Debye-Huckel: ionic-radius: 4 angstrom electrolyte-species-type: weak-acid-associated weak-acid-charge: -1.0 ``` (sec-yaml-edge)= ### `edge` A one-dimensional edge between two surfaces, as {ct}`described here `. Additional fields: `site-density` : The molar density of sites per unit length along the edge Example: ```yaml - name: tpb thermo: edge adjacent-phases: [metal, metal_surface, oxide_surface] elements: [H, O] species: [(tpb)] kinetics: edge reactions: [tpb-reactions] state: {T: 1073.15, coverages: {(tpb): 1.0}} site-density: 5.0e-17 mol/cm ``` (sec-yaml-electron-cloud)= ### `electron-cloud` A phase representing an electron cloud, such as conduction electrons in a metal, as {ct}`described here `. Additional fields: `density` : The density of the bulk metal Example: ```yaml - name: metal thermo: electron-cloud elements: [E] species: [electron] state: T: 1073.15 X: {electron: 1.0} density: 9 g/cm^3 ``` (sec-yaml-fixed-stoichiometry)= ### `fixed-stoichiometry` An incompressible phase with fixed composition, as {ct}`described here `. Example: ```yaml - name: diamond thermo: fixed-stoichiometry elements: [C] species: [C(d)] ``` (sec-yaml-hmw-electrolyte)= ### `HMW-electrolyte` A dilute or concentrated liquid electrolyte phase that obeys the Pitzer formulation for nonideality, as {ct}`described here `. Additional parameters for this model are contained in the `activity-data` field: `activity-data` : The activity data field contains the following fields: `temperature-model` : The form of the Pitzer temperature model. One of `constant`, `linear` or `complex`. The default is `constant`. `A_Debye` : The value of the Debye "A" parameter, or the string `variable` to use a calculation based on the water equation of state. The default is 1.172576 kg^0.5/gmol^0.5, a nominal value for water at 298 K and 1 atm. `max-ionic-strength` : The maximum ionic strength `interactions` : A list of mappings, where each mapping describes a binary or ternary interaction among species. Fields of this mapping include: `species` : A list of one to three species names `beta0` : The $\beta^{(0)}$ parameters for an cation/anion interaction. 1, 2, or 5 values depending on the value of `temperature-model`. `beta1` : The $\beta^{(1)}$ parameters for an cation/anion interaction. 1, 2, or 5 values depending on the value of `temperature-model`. `beta2` : The $\beta^{(2)}$ parameters for an cation/anion interaction. 1, 2, or 5 values depending on the value of `temperature-model`. `Cphi` : The $C^\phi$ parameters for an cation/anion interaction. 1, 2, or 5 values depending on the value of `temperature-model`. `alpha1` : The $\alpha^{(1)}$ parameter for an cation/anion interaction. `alpha2` : The $\alpha^{(2)}$ parameter for an cation/anion interaction. `theta` : The $\theta$ parameters for a like-charged binary interaction. 1, 2, or 5 values depending on the value of `temperature-model`. `lambda` : The $\lambda$ parameters for binary interactions involving at least one neutral species. 1, 2, or 5 values depending on the value of `temperature-model`. `psi` : The $\Psi$ parameters for ternary interactions involving three charged species. 1, 2, or 5 values depending on the value of `temperature-model`. `zeta` : The $\zeta$ parameters for ternary interactions involving one neutral species. 1, 2, or 5 values depending on the value of `temperature-model`. `mu` : The $\mu$ parameters for a neutral species self-interaction. 1, 2, or 5 values depending on the value of `temperature-model`. `cropping-coefficients` : Parameters in the molality exponential cutoff treatment `ln_gamma_k_min` : Default -5.0. `ln_gamma_k_max` : Default 15.0. `ln_gamma_o_min` : Default -6.0. `ln_gamma_o_max` : Default 3.0. Example: ```yaml - name: NaCl_electrolyte thermo: HMW-electrolyte activity-data: temperature-model: complex A_Debye: 1.175930 kg^0.5/gmol^0.5 interactions: - species: [Na+, Cl-] beta0: [0.0765, 0.008946, -3.3158E-6, -777.03, -4.4706] beta1: [0.2664, 6.1608E-5, 1.0715E-6, 0.0, 0.0] beta2: [0.0, 0.0, 0.0, 0.0, 0.0] Cphi: [0.00127, -4.655E-5, 0.0, 33.317, 0.09421] alpha1: 2.0 - species: [H+, Cl-] beta0: [0.1775] beta1: [0.2945] beta2: [0.0] Cphi: [0.0008] alpha1: 2.0 - species: [Na+, OH-] beta0: 0.0864 beta1: 0.253 beta2: 0.0 Cphi: 0.0044 alpha1: 2.0 alpha2: 0.0 - {species: [Cl-, OH-], theta: -0.05} - {species: [Na+, Cl-, OH-], psi: -0.006} - {species: [Na+, H+], theta: 0.036} - {species: [Cl-, Na+, H+], psi: [-0.004]} ``` (sec-yaml-ideal-gas)= ### `ideal-gas` A mixture which obeys the ideal gas law, as {ct}`described here `. Example: ```yaml - name: ohmech thermo: ideal-gas species: [H2, H, O, O2, OH, H2O, HO2, H2O2, AR, N2] kinetics: gas transport: mixture-averaged state: {T: 300.0, P: 1 atm} ``` (sec-yaml-ideal-molal-solution)= ### `ideal-molal-solution` An ideal solution based on the mixing-rule assumption that all molality-based activity coefficients are equal to one, as {ct}`described here `. Additional fields: `standard-concentration-basis` : A string specifying the basis for the standard concentration. One of `unity`, `species-molar-volume`, or `solvent-molar-volume`. `cutoff` : Parameters for cutoff treatments of activity coefficients `model` : `poly` or `polyExp` `gamma_o` : gamma_o value for the cutoff process at the zero solvent point `gamma_k` : gamma_k minimum for the cutoff process at the zero solvent point `X_o` : value of the solute mole fraction that centers the cutoff polynomials for the cutoff = 1 process `c_0` : Parameter in the polyExp cutoff treatment having to do with rate of exponential decay `slope_f` : Parameter in the `polyExp` cutoff treatment `slope_g` : Parameter in the `polyExp` cutoff treatment Example: ```yaml - name: NaCl_electrolyte species: [H2O(L), Cl-, H+, Na+, OH-] thermo: ideal-molal-solution standard-concentration-basis: solvent-molar-volume cutoff: model: polyexp gamma_o: 0.0001 gamma_k: 10.0 X_o: 0.2 c_0: 0.05 slope_f: 0.6 slope_g: 0.0 state: {T: 298.15 K, P: 1.01325e+05 Pa, molalities: {Na+: 6.0954, Cl-: 6.0954, H+: 2.1628e-09, OH-: 1.3977e-06}} ``` (sec-yaml-ideal-condensed)= ### `ideal-condensed` An ideal liquid or solid solution as {ct}`described here `. Additional fields: `standard-concentration-basis` : A string specifying the basis for the standard concentration. One of `unity`, `species-molar-volume`, or `solvent-molar-volume`. Example: ```yaml - name: electrolyte thermo: ideal-condensed species: ['C3H4O3[elyt]', 'C4H6O3[elyt]', 'Li+[elyt]', 'PF6-[elyt]'] state: X: {'C3H4O3[elyt]': 0.47901, 'C4H6O3[elyt]': 0.37563, 'Li+[elyt]': 0.07268, 'PF6-[elyt]': 0.07268} standard-concentration-basis: unity ``` (sec-yaml-ideal-solution-vpss)= ### `ideal-solution-VPSS` An ideal solution model using variable pressure standard state methods as {ct}`described here `. Additional fields: `standard-concentration-basis` : A string specifying the basis for the standard concentration. One of `unity`, `species-molar-volume`, or `solvent-molar-volume`. Example: ```yaml - name: NaCl_electrolyte species: [H2O(L), Na+, Cl-, H+, OH-] thermo: ideal-solution-VPSS standard-concentration-basis: solvent-molar-volume ``` (sec-yaml-ideal-surface)= ### `ideal-surface` An ideal surface between two bulk phases, as {ct}`described here `. Additional fields: `site-density` : The molar density of surface sites Example: ```yaml - name: Pt_surf thermo: ideal-surface adjacent-phases: [gas] elements: [Pt, H, O, C] species: [PT(S), H(S), H2O(S), OH(S), CO(S), CO2(S), CH3(S), CH2(S)s, CH(S), C(S), O(S)] kinetics: surface reactions: all state: T: 900.0 coverages: {O(S): 0.0, PT(S): 0.5, H(S): 0.5} site-density: 2.7063e-09 ``` (sec-yaml-lattice)= ### `lattice` A simple thermodynamic model for a bulk phase, assuming an incompressible lattice of solid atoms, as {ct}`described here `. Additional fields: `site-density` : The molar density of lattice sites Example: ```yaml - name: oxide_bulk thermo: lattice species: [Ox, VO**] state: {T: 1073.15, P: 1.01325e+05, X: {Ox: 0.95, VO**: 0.05}} site-density: 0.0176 mol/cm^3 ``` (sec-yaml-liquid-water-iapws95)= ### `liquid-water-IAPWS95` An implementation of the IAPWS95 equation of state for water {cite:p}`wagner2002`, for the liquid region only as {ct}`described here `. Example: ```yaml - name: liquid-water-IAPWS95 species: [H2O] thermo: liquid-water-IAPWS95 state: {T: 300.0, P: 1.01325e+05} ``` (sec-yaml-margules)= ### `Margules` A phase employing the Margules approximation for the excess Gibbs free energy, as {ct}`described here `. Additional fields: `interactions` : A list of mappings, where each mapping has the following fields: `species` : A list of two species names `excess-enthalpy` : A list of two values specifying the first and second excess enthalpy coefficients for the interaction of the specified species. Defaults to [0, 0]. `excess-entropy` : A list of two values specifying the first and second excess entropy coefficients for the interaction of the specified species. Defaults to [0, 0]. `excess-volume-enthalpy` : A list of two values specifying the first and second enthalpy coefficients for the excess volume interaction of the specified species. Defaults to [0, 0]. `excess-volume-entropy` : A list of two values specifying the first and second entropy coefficients for the excess volume interaction of the specified species. Defaults to [0, 0]. Example: ```yaml - name: MoltenSalt_electrolyte species: [LiCl(L), KCl(L)] thermo: Margules interactions: - species: [KCl(L), LiCl(L)] excess-enthalpy: [-17570. J/gmol, -377 J/gmol] excess-entropy: [-7.627 J/gmol/K, 4.958 J/gmol/K] ``` (sec-yaml-peng-robinson)= ### `Peng-Robinson` A multi-species real gas following the Peng-Robinson equation of state, as {ct}`described here `. The parameters for each species are contained in the corresponding species entries. See [Peng-Robinson species equation of state](sec-yaml-eos-peng-robinson). Example: ```yaml - name: CO2-PR species: [CO2, H2O, H2, CO, CH4, O2, N2] thermo: Peng-Robinson kinetics: bulk state: {T: 300, P: 1 atm, mole-fractions: {CO2: 0.99, H2: 0.01}} ``` :::{versionadded} 3.0 ::: (sec-yaml-plasma)= ### `plasma` A phase for plasma. This phase handles plasma properties such as the electron energy distribution and electron temperature with different models as {ct}`described here `. Additional fields: `electron-energy-distribution` : A mapping with the following fields: `type` : String specifying the type of the electron energy distribution to be used. Supported model strings are: - `isotropic` - `discretized` `shape-factor` : A constant in the isotropic distribution, which is shown as x in the detailed description of this class. The value needs to be a positive number. This field is only used with `isotropic`. Defaults to 2.0. `mean-electron-energy` : Mean electron energy of the isotropic distribution. The default sets the electron temperature equal gas temperature and uses the corresponding electron energy as mean electron energy. This field is only used with `isotropic`. `energy-levels` : A list of values specifying the electron energy levels. The default uses 1001 equal spaced points from 0 to 1 eV. `distribution` : A list of values specifying the discretized electron energy distribution. This field is only used with `discretized`. `normalize` : A flag specifying whether normalizing the discretized electron energy distribution or not. This field is only used with `discretized`. Defaults to `true`. Examples: ```yaml - name: isotropic-electron-energy-plasma thermo: plasma kinetics: gas transport: ionized-gas electron-energy-distribution: type: isotropic shape-factor: 2.0 mean-electron-energy: 1.0 eV energy-levels: [0.0, 0.1, 1.0, 10.0] - name: discretized-electron-energy-plasma thermo: plasma kinetics: gas transport: ionized-gas electron-energy-distribution: type: discretized energy-levels: [0.0, 0.1, 1.0, 10.0] distribution: [0.0, 0.2, 0.7, 0.01] normalize: False ``` :::{versionadded} 2.6 ::: (sec-yaml-pure-fluid)= ### `pure-fluid` A phase representing a pure fluid equation of state for one of several pure substances including liquid, vapor, two-phase, and supercritical regions, as {ct}`described here `. Additional fields: `pure-fluid-name` : Name of the pure fluid model to use: - `carbon-dioxide` - `heptane` - `HFC-134a` - `hydrogen` - `methane` - `nitrogen` - `oxygen` - `water` Example: ```yaml - name: carbon-dioxide thermo: pure-fluid species: [CO2] state: {T: 280.0, P: 1.01325e+05} pure-fluid-name: carbon-dioxide ``` (sec-yaml-redlich-kister)= ### `Redlich-Kister` A phase employing the Redlich-Kister approximation for the excess Gibbs free energy, as {ct}`described here `. Additional fields: `interactions` : A list of mappings, where each mapping has the following fields: `species` : A list of two species names `excess-enthalpy` : A list of polynomial coefficients for the excess enthalpy of the specified binary interaction `excess-entropy` : A list of polynomial coefficients for the excess entropy of the specified binary interaction Example: ```yaml - name: LiC6_and_Vacancies thermo: Redlich-Kister interactions: - species: [Li(C6), V(C6)] excess-enthalpy: [-3.268e+06, 3.955e+06, -4.573e+06, 6.147e+06, -3.339e+06, 1.117e+07, 2.997e+05, -4.866e+07, 1.362e+05, 1.373e+08, -2.129e+07, -1.722e+08, 3.956e+07, 9.302e+07, -3.280e+07] excess-entropy: [0.0] ``` (sec-yaml-redlich-kwong)= ### `Redlich-Kwong` A multi-species Redlich-Kwong phase as {ct}`described here `. The parameters for each species are contained in the corresponding species entries. See [Redlich-Kwong species equation of state](sec-yaml-eos-redlich-kwong).