Thermo Special Interest Group met on January 24, 2023 from 9:30 am till 11:30 am.
Agenda
- Errata & Clarifications on Thermodynamic and Physical Properties interface specification v1.1
Participants
AmsterCHEM (represented by Jasper van BATEN), BASF (represented by Sergej BLAGOV), KBC (represented by Richard SZCZEPANSKI), University of Cape Town (represented by Klaus MÖLLER), Michel PONS (Consultant as Chief Technology Officer).
Highlights
Thermo SIG worked on version 0.06 of the Errata & Clarifications specific to the specification of interface ICapeThermoCompounds within the Thermodynamic and Physical Properties interface specification v1.1.
Thermo SIG clarified the notion of “supported” for Physical Properties.
The clarification was brought in specifically in the notes accompanying the detailed description of method GetPDependentPropList, but is applicable to other methods that are providing lists of “supported” properties.
It is now recognized and stated that the information recovered by a client from a server implementing ICapeThermoCompounds is primarily about what is not supported rather than what is supported. “Support” for a Physical Property means that the method that gives access to the value of Physical Properties, succeeds in doing so for that Physical Property, at least for one Compound present in the list returned by GetCompoundList and, if adequate, at least for one temperature or one pressure value.
This clarification of the notion of support is needed to avoid seeing returned lists containing identifiers of Physical Properties that do not match this requirement, giving therefore false hope on what can be effectively provided by the software component implementing ICapeThermoCompounds.
A remark was also added on the expected behavior of GetPDependentPropList and the likes when implemented on a Material Object. If the call made on the Material Object to get its list of supported properties, is forwarded to a Property Package, this may introduce a bias in the information provided since it applies then to the list of Compounds supported by the Property Package rather than to the list of Compounds defined on the Material Object. The list of Compounds defined on the Material Object may be just a subset of the list of Compounds supported by the Property Package. So, for that subset, a Physical Property declared as supported at the Property Package level, may well not be “supported” at the Material Object level, as per the definition of support mentioned above.
It was also clearly emphasized that even if there is no Physical Property of some kind (constant, temperature-dependent, pressure-dependent) supported by the software component implementing ICapeThermoCompounds, the methods returning lists of each kind of Physical Properties, must not raise an exception.
Rather, they must return an empty list. While this is strictky speaking a modification of the interface specification, since the specification allowed for exception ECapeNoImpl to be returned by these methods, it is expected that no existing implementation of ICapeThermoCompounds returns such an exception, even if no property of some kind is supported. Therefore, removing from the specification the pôssibility to raise ECapeNoImpl is not considered as a game changer.
The next meeting of the Thermo SIG is scheduled for February 1, 2023 at 9:30 am.
