Represents a single nuclear reaction from a specific data source. More...

#include <reaction.h>

Inheritance diagram for gridfire::Reaction:

Public Member Functions
virtual	~Reaction ()=default
	Virtual destructor for correct polymorphic cleanup.

virtual double	calculate_rate (double T9, double rho, double Ye, double mue, const std::vector< double > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const=0
	Compute the temperature- and composition-dependent reaction rate.

virtual CppAD::AD< double >	calculate_rate (CppAD::AD< double > T9, CppAD::AD< double > rho, CppAD::AD< double > Ye, CppAD::AD< double > mue, const std::vector< CppAD::AD< double > > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const=0
	AD-enabled reaction rate for algorithmic differentiation.

virtual std::string_view	id () const=0
	A stable, unique identifier for this reaction instance.

virtual const std::vector< fourdst::atomic::Species > &	reactants () const=0
	Ordered list of reactant species.

virtual const std::vector< fourdst::atomic::Species > &	products () const=0
	Ordered list of product species.

virtual bool	contains (const fourdst::atomic::Species &species) const=0
	True if the species appears as a reactant or a product.

virtual bool	contains_reactant (const fourdst::atomic::Species &species) const=0
	True if the species appears among the reactants.

virtual bool	contains_product (const fourdst::atomic::Species &species) const=0
	True if the species appears among the products.

virtual bool	is_reverse () const=0
	Whether this object represents a reverse (backward) rate.

virtual std::unordered_set< fourdst::atomic::Species >	all_species () const=0
	Set of all unique species appearing in the reaction.

virtual std::unordered_set< fourdst::atomic::Species >	reactant_species () const=0
	Set of unique reactant species.

virtual std::unordered_set< fourdst::atomic::Species >	product_species () const=0
	Set of unique product species.

virtual size_t	num_species () const=0
	Number of unique species involved in the reaction.

virtual std::unordered_map< fourdst::atomic::Species, int >	stoichiometry () const=0
	Full stoichiometry map for this reaction.

virtual int	stoichiometry (const fourdst::atomic::Species &species) const=0
	Stoichiometric coefficient for a particular species.

virtual uint64_t	hash (uint64_t seed) const=0
	Stable content-based hash for this reaction.

virtual double	qValue () const=0
	Q-value of the reaction (typically MeV), positive if exothermic.

virtual double	calculate_energy_generation_rate (const double T9, const double rho, const double Ye, double mue, const std::vector< double > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const
	Convenience: energy generation rate from this reaction (double version).

virtual CppAD::AD< double >	calculate_energy_generation_rate (const CppAD::AD< double > &T9, const CppAD::AD< double > &rho, const CppAD::AD< double > &Ye, const CppAD::AD< double > &mue, const std::vector< CppAD::AD< double > > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const
	Convenience: AD-enabled energy generation rate (AD version).

virtual double	calculate_log_rate_partial_deriv_wrt_T9 (double T9, double rho, double Ye, double mue, const fourdst::composition::Composition &comp) const=0
	Logarithmic partial derivative of the rate with respect to temperature.

virtual ReactionType	type () const=0
	Category of this reaction (e.g., REACLIB, WEAK, LOGICAL_REACLIB).

virtual std::unique_ptr< Reaction >	clone () const=0
	Polymorphic deep copy.

Friends
std::ostream &	operator<< (std::ostream &os, const Reaction &r)

Detailed Description

Represents a single nuclear reaction from a specific data source.

This class encapsulates all properties of a single nuclear reaction as defined in formats like REACLIB, including reactants, products, Q-value, and rate coefficients from a particular evaluation (source).

Example:

// Assuming species and rate coefficients are defined
Reaction p_gamma_d(
    "H_1_H_1_to_H_2", "p(p,g)d", 1, {H_1, H_1}, {H_2}, 5.493, "st08", rate_coeffs
);
double rate = p_gamma_d.calculate_rate(0.1); // T9 = 0.1

Constructor & Destructor Documentation

◆ ~Reaction()

virtual gridfire::reaction::Reaction::~Reaction ( )

virtualdefault

Virtual destructor for correct polymorphic cleanup.

Member Function Documentation

◆ all_species()

virtual std::unordered_set< fourdst::atomic::Species > gridfire::reaction::Reaction::all_species ( ) const

nodiscardpure virtual

Set of all unique species appearing in the reaction.

Returns: Unordered set of all reactants and products (no duplicates).

◆ calculate_energy_generation_rate() [1/2]

virtual CppAD::AD< double > gridfire::reaction::Reaction::calculate_energy_generation_rate	(	const CppAD::AD< double > &	T9,
		const CppAD::AD< double > &	rho,
		const CppAD::AD< double > &	Ye,
		const CppAD::AD< double > &	mue,
		const std::vector< CppAD::AD< double > > &	Y,
		const std::unordered_map< size_t, fourdst::atomic::Species > &	index_to_species_map ) const

inlinenodiscardvirtual

Convenience: AD-enabled energy generation rate (AD version).

Default implementation multiplies the AD rate by the reaction Q-value. Electron quantities (Ye, mue) are ignored in this default, so override if they contribute.

Parameters

T9	Temperature in GK as CppAD::AD<double>.
rho	Mass density as CppAD::AD<double>.
Ye	Electron fraction as CppAD::AD<double> (ignored by default).
mue	Electron chemical potential as CppAD::AD<double> (ignored by default).
Y	Composition vector as CppAD::AD<double> values.
index_to_species_map	Mapping from state-vector index to Species.

Returns: Energy generation rate as CppAD::AD<double>.

◆ calculate_energy_generation_rate() [2/2]

virtual double gridfire::reaction::Reaction::calculate_energy_generation_rate	(	const double	T9,
		const double	rho,
		const double	Ye,
		double	mue,
		const std::vector< double > &	Y,
		const std::unordered_map< size_t, fourdst::atomic::Species > &	index_to_species_map ) const

inlinenodiscardvirtual

Convenience: energy generation rate from this reaction (double version).

Default implementation multiplies the scalar rate by the reaction Q-value. Electron quantities (Ye, mue) are ignored in this default, so override in derived classes if needed. Sign convention follows qValue().

Parameters

T9	Temperature in GK (10^9 K).
rho	Mass density (g cm^-3).
Ye	Electron fraction (ignored by default implementation).
mue	Electron chemical potential (ignored by default implementation).
Y	Composition vector.
index_to_species_map	Mapping from state-vector index to Species.

Returns: Energy generation rate, typically rate * qValue().

◆ calculate_log_rate_partial_deriv_wrt_T9()

virtual double gridfire::reaction::Reaction::calculate_log_rate_partial_deriv_wrt_T9	(	double	T9,
		double	rho,
		double	Ye,
		double	mue,
		const fourdst::composition::Composition &	comp ) const

nodiscardpure virtual

Logarithmic partial derivative of the rate with respect to temperature.

Implementations return d(ln rate)/d(ln T9) or an equivalent measure (as documented by the concrete class), evaluated at the provided state.

Parameters

T9	Temperature in GK (10^9 K).
rho	Mass density (g cm^-3).
Ye	Electron fraction.
mue	Electron chemical potential.
comp	Composition object providing composition in a convenient form.

Returns: The logarithmic temperature derivative of the rate.

◆ calculate_rate() [1/2]

virtual CppAD::AD< double > gridfire::reaction::Reaction::calculate_rate	(	CppAD::AD< double >	T9,
		CppAD::AD< double >	rho,
		CppAD::AD< double >	Ye,
		CppAD::AD< double >	mue,
		const std::vector< CppAD::AD< double > > &	Y,
		const std::unordered_map< size_t, fourdst::atomic::Species > &	index_to_species_map ) const

nodiscardpure virtual

AD-enabled reaction rate for algorithmic differentiation.

This overload mirrors calculate_rate(double, ...) but operates on CppAD types to enable derivative calculations w.r.t. its inputs.

Parameters

T9	Temperature in GK as CppAD::AD<double>.
rho	Mass density as CppAD::AD<double>.
Ye	Electron fraction as CppAD::AD<double>.
mue	Electron chemical potential as CppAD::AD<double>.
Y	Composition vector as CppAD::AD<double> values.
index_to_species_map	Mapping from state-vector index to Species, used to interpret Y.

Returns: The reaction rate as a CppAD::AD<double> value.

◆ calculate_rate() [2/2]

virtual double gridfire::reaction::Reaction::calculate_rate	(	double	T9,
		double	rho,
		double	Ye,
		double	mue,
		const std::vector< double > &	Y,
		const std::unordered_map< size_t, fourdst::atomic::Species > &	index_to_species_map ) const

nodiscardpure virtual

Compute the temperature- and composition-dependent reaction rate.

This is the primary interface used by the network to obtain the rate of a single reaction at the given thermodynamic state and composition. The exact units and normalization are defined by the concrete implementation (e.g., REACLIB typically provides NA<sigma v> with units depending on the reaction order). Implementations may use density/electron properties for weak processes or screening, and the composition vector for multi-body reactions.

Parameters

T9	Temperature in GK (10^9 K).
rho	Mass density (g cm^-3). May be unused for some reaction types.
Ye	Electron fraction. May be unused depending on the reaction type.
mue	Electron chemical potential. May be unused depending on the reaction type.
Y	Composition vector (molar abundances or number fractions) indexed consistently with index_to_species_map.
index_to_species_map	Mapping from state-vector index to Species, used to interpret Y.

Returns: The reaction rate for the forward direction, with units/normalization defined by the specific model (implementation must document its convention).

◆ clone()

virtual std::unique_ptr< Reaction > gridfire::reaction::Reaction::clone ( ) const

nodiscardpure virtual

Polymorphic deep copy.

Returns: A std::unique_ptr owning a new Reaction equal to this one.

◆ contains()

virtual bool gridfire::reaction::Reaction::contains ( const fourdst::atomic::Species & species ) const

nodiscardpure virtual

True if the species appears as a reactant or a product.

Parameters

species Species to test.

Returns: Whether the species participates in the reaction (either side).

◆ contains_product()

virtual bool gridfire::reaction::Reaction::contains_product ( const fourdst::atomic::Species & species ) const

nodiscardpure virtual

True if the species appears among the products.

Parameters

species Species to test.

Returns: Whether the species is a product.

◆ contains_reactant()

virtual bool gridfire::reaction::Reaction::contains_reactant ( const fourdst::atomic::Species & species ) const

nodiscardpure virtual

True if the species appears among the reactants.

Parameters

species Species to test.

Returns: Whether the species is a reactant.

◆ hash()

virtual uint64_t gridfire::reaction::Reaction::hash ( uint64_t seed ) const

nodiscardpure virtual

Stable content-based hash for this reaction.

Intended for use in caches, sets, and order-independent hashing of Reaction collections. Implementations should produce the same value across processes for the same content and seed.

Parameters

seed	Seed value to initialize/mix into the hash.

Returns: 64-bit hash value.

◆ id()

virtual std::string_view gridfire::reaction::Reaction::id ( ) const

nodiscardpure virtual

A stable, unique identifier for this reaction instance.

Returns: String view of the reaction ID (stable across runs and suitable for lookups).

◆ is_reverse()

virtual bool gridfire::reaction::Reaction::is_reverse ( ) const

nodiscardpure virtual

Whether this object represents a reverse (backward) rate.

Implementations may pair forward/reverse rates for detailed balance. This flag indicates that the parameterization corresponds to the reverse direction.

Returns: True for a reverse rate, false for a forward rate.

◆ num_species()

virtual size_t gridfire::reaction::Reaction::num_species ( ) const

nodiscardpure virtual

Number of unique species involved in the reaction.

Returns: Count of distinct species across reactants and products.

◆ product_species()

virtual std::unordered_set< fourdst::atomic::Species > gridfire::reaction::Reaction::product_species ( ) const

nodiscardpure virtual

Set of unique product species.

Returns: Unordered set of product species (no duplicates).

◆ products()

virtual const std::vector< fourdst::atomic::Species > & gridfire::reaction::Reaction::products ( ) const

nodiscardpure virtual

Ordered list of product species.

Multiplicity is represented by duplicates if applicable.

Returns: Const reference to the vector of products.

◆ qValue()

virtual double gridfire::reaction::Reaction::qValue ( ) const

nodiscardpure virtual

Q-value of the reaction (typically MeV), positive if exothermic.

Returns: Reaction Q-value used for energy accounting.

◆ reactant_species()

virtual std::unordered_set< fourdst::atomic::Species > gridfire::reaction::Reaction::reactant_species ( ) const

nodiscardpure virtual

Set of unique reactant species.

Returns: Unordered set of reactant species (no duplicates).

◆ reactants()

virtual const std::vector< fourdst::atomic::Species > & gridfire::reaction::Reaction::reactants ( ) const

nodiscardpure virtual

Ordered list of reactant species.

Multiplicity is represented by duplicates, e.g., (p, p) would list H1 twice.

Returns: Const reference to the vector of reactants.

◆ stoichiometry() [1/2]

virtual std::unordered_map< fourdst::atomic::Species, int > gridfire::reaction::Reaction::stoichiometry ( ) const

nodiscardpure virtual

Full stoichiometry map for this reaction.

Coefficients are negative for reactants and positive for products; multiplicity is reflected in the magnitude (e.g., 2H -> He gives H: -2, He: +1).

Returns: Map from Species to integer stoichiometric coefficient.

◆ stoichiometry() [2/2]

virtual int gridfire::reaction::Reaction::stoichiometry ( const fourdst::atomic::Species & species ) const

nodiscardpure virtual

Stoichiometric coefficient for a particular species.

Parameters

species Species for which to query the coefficient.

Returns: Negative for reactants, positive for products, zero if absent.

◆ type()

virtual ReactionType gridfire::reaction::Reaction::type ( ) const

nodiscardpure virtual

Category of this reaction (e.g., REACLIB, WEAK, LOGICAL_REACLIB).

Returns: Enumerated reaction type for runtime dispatch and filtering.

Friends And Related Symbol Documentation

◆ operator<<

std::ostream & operator<<	(	std::ostream &	os,
		const Reaction &	r )

friend

The documentation for this class was generated from the following file:

src/include/gridfire/reaction/reaction.h

Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ ~Reaction()

Member Function Documentation

◆ all_species()

◆ calculate_energy_generation_rate() [1/2]

◆ calculate_energy_generation_rate() [2/2]

◆ calculate_log_rate_partial_deriv_wrt_T9()

◆ calculate_rate() [1/2]

◆ calculate_rate() [2/2]

◆ clone()

◆ contains()

◆ contains_product()

◆ contains_reactant()

◆ hash()

◆ id()

◆ is_reverse()

◆ num_species()

◆ product_species()

◆ products()

◆ qValue()

◆ reactant_species()

◆ reactants()

◆ stoichiometry() [1/2]

◆ stoichiometry() [2/2]

◆ type()

Friends And Related Symbol Documentation

◆ operator<<