# Database (rmgpy.data)¶

## General classes¶

Class/Function Description
Entry An entry in a database
Database A database of entries
LogicNode A node in a database that represents a logical collection of entries
LogicAnd A logical collection of entries, where all entries in the collection must match
LogicOr A logical collection of entries, where any entry in the collection can match
makeLogicNode() Create a LogicNode based on a string representation

## Thermodynamics database¶

Class Description
ThermoDepository A depository of all thermodynamics parameters for one or more species
ThermoLibrary A library of curated thermodynamics parameters for one or more species
ThermoGroups A representation of a portion of a database for implementing the Benson group additivity method
ThermoDatabase An entire thermodynamics database, including depositories, libraries, and groups

## Kinetics database¶

Class Description
DepositoryReaction A reaction with kinetics determined from querying a kinetics depository
LibraryReaction A reaction with kinetics determined from querying a kinetics library
TemplateReaction A reaction with kinetics determined from querying a kinetics group additivity or rate rules method
ReactionRecipe A sequence of actions that represent the process of a chemical reaction
KineticsDepository A depository of all kinetics parameters for one or more reactions
KineticsLibrary A library of curated kinetics parameters for one or more reactions
KineticsGroups A set of group additivity values for a reaction family, organized in a tree
KineticsRules A set of rate rules for a reaction family
KineticsFamily A kinetics database for one reaction family, including depositories, libraries, groups, and rules
KineticsDatabase A kinetics database for all reaction families, including depositories, libraries, groups, and rules

## Statistical mechanics database¶

Class Description
GroupFrequencies A set of characteristic frequencies for a group in the frequency database
StatmechDepository A depository of all statistical mechanics parameters for one or more species
StatmechLibrary A library of curated statistical mechanics parameters for one or more species
StatmechGroups A set of characteristic frequencies for various functional groups, organized in a tree
StatmechDatabase An entire statistical mechanics database, including depositories, libraries, and groups

## Statistical mechanics fitting¶

Class/Function Description
DirectFit DQED class for fitting a small number of vibrational frequencies and hindered rotors
PseudoFit DQED class for fitting a large number of vibrational frequencies and hindered rotors by assuming degeneracies for both
PseudoRotorFit DQED class for fitting a moderate number of vibrational frequencies and hindered rotors by assuming degeneracies for hindered rotors only
fitStatmechDirect() Directly fit a small number of vibrational frequencies and hindered rotors
fitStatmechPseudo() Fit a large number of vibrational frequencies and hindered rotors by assuming degeneracies for both
fitStatmechPseudoRotors() Fit a moderate number of vibrational frequencies and hindered rotors by assuming degeneracies for hindered rotors only
fitStatmechToHeatCapacity() Fit vibrational and torsional degrees of freedom to heat capacity data

## Exceptions¶

Exception Description
DatabaseError Raised when an error occurs while working with the database
InvalidActionError Raised when an error occurs while applying a reaction recipe
UndeterminableKineticsError Raised when the kinetics of a given reaction cannot be determined
StatmechFitError Raised when an error occurs while fitting internal degrees of freedom to heat capacity data