# arkane.PressureDependenceJob¶

class arkane.PressureDependenceJob(network, Tmin=None, Tmax=None, Tcount=0, Tlist=None, Pmin=None, Pmax=None, Pcount=0, Plist=None, maximumGrainSize=None, minimumGrainCount=0, method=None, interpolationModel=None, maximumAtoms=None, activeKRotor=True, activeJRotor=True, rmgmode=False, sensitivity_conditions=None, sensitivity_perturbation=0)

A representation of a pressure dependence job. The attributes are:

Attribute

Description

Tmin

The minimum temperature at which to compute $$k(T,P)$$ values

Tmax

The maximum temperature at which to compute $$k(T,P)$$ values

Tcount

The number of temperatures at which to compute $$k(T,P)$$ values

Pmin

The minimum pressure at which to compute $$k(T,P)$$ values

Pmax

The maximum pressure at which to compute $$k(T,P)$$ values

Pcount

The number of pressures at which to compute $$k(T,P)$$ values

Emin

The minimum energy to use to compute $$k(T,P)$$ values

Emax

The maximum energy to use to compute $$k(T,P)$$ values

maximumGrainSize

The maximum energy grain size to use to compute $$k(T,P)$$ values

minimumGrainCount

The minimum number of energy grains to use to compute $$k(T,P)$$ values

method

The method to use to reduce the master equation to $$k(T,P)$$ values

interpolationModel

The interpolation model to fit to the computed $$k(T,P)$$ values

maximumAtoms

The maximum number of atoms to apply pressure dependence to (in RMG jobs)

activeKRotor

A flag indicating whether to treat the K-rotor as active or adiabatic

activeJRotor

A flag indicating whether to treat the J-rotor as active or adiabatic

rmgmode

A flag that toggles “RMG mode”, described below

network

The unimolecular reaction network

Tlist

An array of temperatures at which to compute $$k(T,P)$$ values

Plist

An array of pressures at which to compute $$k(T,P)$$ values

Elist

An array of energies to use to compute $$k(T,P)$$ values

In RMG mode, several alterations to the k(T,P) algorithm are made both for speed and due to the nature of the approximations used:

• Densities of states are not computed for product channels

• Arbitrary rigid rotor moments of inertia are included in the active modes; these cancel in the ILT and equilibrium expressions

• k(E) for each path reaction is computed in the direction A -> products, where A is always an explored isomer; the high-P kinetics are reversed if necessary for this purpose

• Thermodynamic parameters are always used to compute the reverse k(E) from the forward k(E) for each path reaction

RMG mode should be turned off by default except in RMG jobs.

property Plist

The pressures at which the k(T,P) values are computed.

property Pmax

The maximum pressure at which the computed k(T,P) values are valid, or None if not defined.

property Pmin

The minimum pressure at which the computed k(T,P) values are valid, or None if not defined.

property Tlist

The temperatures at which the k(T,P) values are computed.

property Tmax

The maximum temperature at which the computed k(T,P) values are valid, or None if not defined.

property Tmin

The minimum temperature at which the computed k(T,P) values are valid, or None if not defined.

copy()

Return a copy of the pressure dependence job.

draw(output_directory, file_format='pdf')

Generate a PDF drawing of the pressure-dependent reaction network. This requires that Cairo and its Python wrapper be available; if not, the drawing is not generated.

You may also generate different formats of drawings, by changing format to one of the following: pdf, svg, png.

execute(output_file, plot, file_format='pdf', print_summary=True)

Execute a PressureDependenceJob

fit_interpolation_model(Tdata, Pdata, kdata, k_units)

Fit an interpolation model to a pressure dependent rate

fit_interpolation_models()

Fit all pressure dependent rates with interpolation models

generate_P_list()

Returns an array of pressures based on the interpolation model, minimum and maximum pressures Pmin and Pmax in Pa, and the number of pressures Pcount. For Chebyshev polynomials a Gauss-Chebyshev distribution is used; for all others a linear distribution on an logarithmic pressure domain is used. Note that the Gauss-Chebyshev grid does not place Pmin and Pmax at the endpoints, yet the interpolation is still valid up to these values.

generate_T_list()

Returns an array of temperatures based on the interpolation model, minimum and maximum temperatures Tmin and Tmax in K, and the number of temperatures Tcount. For Chebyshev polynomials a Gauss-Chebyshev distribution is used; for all others a linear distribution on an inverse temperature domain is used. Note that the Gauss-Chebyshev grid does not place Tmin and Tmax at the endpoints, yet the interpolation is still valid up to these values.

initialize()

Initialize a PressureDependenceJob

property maximum_grain_size

The maximum allowed energy grain size, or None if not defined.

plot(output_directory)

Plot pressure dependent rates

save(output_file)

Save the output of a pressure dependent job

save_input_file(path)

Save an Arkane input file for the pressure dependence job to path on disk.