Rotor Class Reference

Class Rotor represents a non-rigid quantum-mechanical rotor. More...

#include <rotor.h>

Public Member Functions
	Rotor ()
	Default Constructor.
virtual	~Rotor ()
	Destructor.
	Rotor (doublereal Bv, doublereal dipoleMoment=0.0, doublereal Dv=0.0, doublereal Hv=0.0)
	Full Constructor.
doublereal	energy_w (int J)
	The energy of the level with rotational quantum number J, in wavenumber units.
int	degeneracy (int J)
	The number of quantum states with the same J.
doublereal	partitionFunction (doublereal T, int cutoff=-1)
	The rotational partition function.
doublereal	frequency (int J_lower, int J_upper)
	The frequency at which radiation is absorbed by a transition from the lower to the upper state in wavenumber units.
doublereal	relPopulation (int J, doublereal T)
	Ratio of the population of all states with rotational quantum number J to the ground state population.
doublereal	population (int J, doublereal T)
doublereal	intensity (int J_lower, int J_upper, doublereal T)
	The spectral intensity of a rotational transition.

Protected Attributes
doublereal	m_Bv
doublereal	m_Dv
doublereal	m_Hv
doublereal	m_dipole

Detailed Description

Class Rotor represents a non-rigid quantum-mechanical rotor.

Definition at line 28 of file rotor.h.

Constructor & Destructor Documentation

Rotor ( )

inline

Default Constructor.

Definition at line 33 of file rotor.h.

virtual ~Rotor ( )

inlinevirtual

Destructor.

Definition at line 36 of file rotor.h.

Rotor	(	doublereal	Bv,
		doublereal	dipoleMoment = 0.0,
		doublereal	Dv = 0.0,
		doublereal	Hv = 0.0
	)

Full Constructor.

Constructor.

Parameters

Bv	Rotational constant, wavenumbers. permanent dipole moment.
Dv	Coefficient describing centrifugal effects on the bond length. For a rigid rotor, Bv = 0.
Hv	Coefficient describing higher-order vibration-rotation interactions. For a rigid rotor, Hv = 0.

Definition at line 24 of file rotor.cpp.

Member Function Documentation

doublereal energy_w

(

int

J

)

The energy of the level with rotational quantum number J, in wavenumber units.

\[ E(J) = J(J+1)B - [J(J+1)]^2 D + [J(J+1)]^3H \]

For a rigid rotor, only B is non-zero. The parameters B, D, and H are set in the constructor.

Definition at line 39 of file rotor.cpp.

Referenced by Rotor::frequency(), Rotor::partitionFunction(), and Rotor::relPopulation().

int degeneracy

(

int

J

)

The number of quantum states with the same J.

For a quantum-mechanical rotor, this is simply 2J+1.

Definition at line 49 of file rotor.cpp.

Referenced by Rotor::partitionFunction(), and Rotor::relPopulation().

doublereal partitionFunction	(	doublereal	T,
		int	cutoff = -1
	)

The rotational partition function.

If T/Trot > 100, then the classical value (T/Trot) is is returned. Otherwise, it is computed as a sum

\[ z = \sum_{J=0}^{J_{max}} (2J + 1) \exp(-E(J)/kT) \]

Definition at line 63 of file rotor.cpp.

References Cantera::Boltzmann, Rotor::degeneracy(), Rotor::energy_w(), and Cantera::wnum_to_J().

doublereal frequency	(	int	J_lower,
		int	J_upper
	)

The frequency at which radiation is absorbed by a transition from the lower to the upper state in wavenumber units.

Definition at line 95 of file rotor.cpp.

References Rotor::energy_w().

doublereal relPopulation	(	int	J,
		doublereal	T
	)

Ratio of the population of all states with rotational quantum number J to the ground state population.

Definition at line 86 of file rotor.cpp.

References Cantera::Boltzmann, Rotor::degeneracy(), Rotor::energy_w(), and Cantera::wnum_to_J().

Referenced by Rotor::intensity().

doublereal intensity	(	int	J_lower,
		int	J_upper,
		doublereal	T
	)

The spectral intensity of a rotational transition.

Definition at line 103 of file rotor.cpp.

References Rotor::relPopulation().

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

• rotor.h
• rotor.cpp