Polyrate Enhancements:
A note on the status of recent enhancements to Polyrate
Major enhancements in version 2017C:

In the SSQRRK utility code, a new approximation for treating unimolecular isomerization reaction has been added; the FE factor now can be evaluated via numerical integration instead of using the approximated analytical formula.
Major enhancements for version 20162A:

A utility code for computing pressuredependent rate constants by using SSQRRK theory is added, which is able to include the variational effects, multidimensional tunneling, and various vibrational and torsional anharmonicity into the computed pressuredependent rate constants and the SSQRRK microcanonical rate constants.
Major enhancements for version 2016:

The torsional anharmonicity can be computed along the reaction coordinate based on the singlestructure MST(C) (MST method with coupled torsional potentials) formalism.

The number of states calculation that is required for μVT is now programmed much more efficiently by the extended BeyerSchwinehart method. Now there is no significant difference between CVT and μVT as far as computational cost.
Major enhancements for version 2010:
 One new keyword "FREQINCR" is added to raise low frequencies to a certain
number (e.g., 50 or 100 cm^{1}) to approximately account for anharmonicity.
 In rate calculations for barrierless association reactions by VRCVTST, the reverse
reaction (dissociation) rate is also calculated by the equilibrium constant and the
association rate.

The SPRNG 2.0 package is included in the Polyrate distribution.
 In VRCVTST calculations, in calculating the total number of available states, the integrat
ion over the projection on the principal axis (K) of the total angular momentum J
is calculated analytically.
 Several methods for treating torsions, in particular the RPG, AS, SRPG, and SAS methods,
are implemented.
A summary of major enhancements from versions 7.2 to 2008:

Variable reaction coordinate variational transition state theory with multifaceted
dividing surfaces for barrierless association reactions was implemented, and the code
was parallized using MPI: 2008

Default unit changed from Bohr to Angstrom in the input (fu5) and output (fu6) files: 9.7

Compatibility with the gnu fortran compiler: 9.4

Interpolated LCG algorithm (ILCG): 8.9

Version 4 of largecurvature tunneling approximation (LCT4): 8.5

Nonequilibrium solvation calculations: 8.2

IVTSTM through the hooks: 8.0

Variational reaction path (VRP) algorithm: 8.0

Variational transition state theory with interpolated single point energies
(VTSTISPE): 8.0

Interpolated variational transition state theory by mapping (IVTSTM),
an IVTST method which allows arbitrary numbers of points along the reaction
path, arbitrary numbers of points at which Hessians are computed, and leads
to faster convergence of direct dynamics calculations: 7.8

RODS algorithm for ReOrienting the Dividing Surface to allow VTST calculations
with larger step sizes: 7.8

Redundant internal coordinates: 7.4

Ability to optimize the reactants, the products, and the saddle point in
separate runs: 7.4

Curvilinear coordinates available for all standard types (stretches, nondegenerate
bends, torsions, and degenerate bends): 7.2

ICL and Eckart options for VTSTIC method: 7.2