# rmgpy.species.Species¶

class rmgpy.species.Species

A chemical species, representing a local minimum on a potential energy surface. The attributes are:

Attribute Description
index A unique nonnegative integer index
label A descriptive string label
thermo The heat capacity model for the species
conformer The molecular conformer for the species
molecule A list of the Molecule objects describing the molecular structure
transportData A set of transport collision parameters
molecularWeight The molecular weight of the species
energyTransferModel The collisional energy transfer model to use
reactive
True if the species participates in reaction families, False if not
Reaction libraries and seed mechanisms that include the species are always considered regardless of this variable
props A generic ‘properties’ dictionary to store user-defined flags
aug_inchi Unique augmented inchi

note: rmg.model.Species inherits from this class, and adds some extra methods.

calculateCp0()

Return the value of the heat capacity at zero temperature in J/mol*K.

calculateCpInf()

Return the value of the heat capacity at infinite temperature in J/mol*K.

copy()

Create a copy of the current species. If the kw argument ‘deep’ is True, then a deep copy will be made of the Molecule objects in self.molecule.

For other complex attributes, a deep copy will always be made.

fromAdjacencyList()

Load the structure of a species as a Molecule object from the given adjacency list adjlist and store it as the first entry of a list in the molecule attribute. Does not generate resonance isomers of the loaded molecule.

fromSMILES()

Load the structure of a species as a Molecule object from the given SMILES string smiles and store it as the first entry of a list in the molecule attribute. Does not generate resonance isomers of the loaded molecule.

generateEnergyTransferModel()

Generate the collisional energy transfer model parameters for the species. This “algorithm” is very much in need of improvement.

generateResonanceIsomers()

Generate all of the resonance isomers of this species. The isomers are stored as a list in the molecule attribute. If the length of molecule is already greater than one, it is assumed that all of the resonance isomers have already been generated.

generateStatMech()

Generate molecular degree of freedom data for the species. You must have already provided a thermodynamics model using e.g. generateThermoData().

generateTransportData()

Generate the transportData parameters for the species.

getDensityOfStates()

Return the density of states $$\rho(E) \ dE$$ at the specified energies Elist in J/mol above the ground state.

getEnthalpy()

Return the enthalpy in J/mol for the species at the specified temperature T in K.

getEntropy()

Return the entropy in J/mol*K for the species at the specified temperature T in K.

getFreeEnergy()

Return the Gibbs free energy in J/mol for the species at the specified temperature T in K.

getHeatCapacity()

Return the heat capacity in J/mol*K for the species at the specified temperature T in K.

getPartitionFunction()

Return the partition function for the species at the specified temperature T in K.

getSumOfStates()

Return the sum of states $$N(E)$$ at the specified energies Elist in J/mol.

getSymmetryNumber()

Get the symmetry number for the species, which is the highest symmetry number amongst its resonance isomers. This function is currently used for website purposes and testing only as it requires additional calculateSymmetryNumber calls.

getThermoData()

Returns a thermoData object of the current Species object.

If the thermo object already exists, it is either of the (Wilhoit, ThermoData) type, or it is a Future.

If the type of the thermo attribute is Wilhoit, or ThermoData, then it is converted into a NASA format.

If it is a Future, then a blocking call is made to retrieve the NASA object. If the thermo object did not exist yet, the thermo object is generated.

getTransportData()

Returns the transport data associated with this species, and calculates it if it is not yet available.

hasStatMech()

Return True if the species has statistical mechanical parameters, or False otherwise.

hasThermo()

Return True if the species has thermodynamic parameters, or False otherwise.

isIsomorphic()

Return True if the species is isomorphic to other, which can be either a Molecule object or a Species object.

toAdjacencyList()

Return a string containing each of the molecules’ adjacency lists.

toCantera()

Converts the RMG Species object to a Cantera Species object with the appropriate thermo data.

toChemkin()

Return the chemkin-formatted string for this species.