This version of ATcT results was generated by additional expansion of version 1.122x  to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions , the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm-1 , as well as the study of the reversible reaction C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5 
The elements in their standard states are listed first; the listing order of the other species follows the actual order from the ATcT solution file, which roughly reflects the number of thermochemically-relevant determinations that include the species in question (highest first). The intent is to convey a very approximate indication of the robustness of the listed values, which is generally higher toward the top of the list and lower toward the bottom.
For species other than elements in their standard states, the Species Name acts as a link to the page itemizing the most important contributors to the provenance of its ATcT enthalpy of formation, other highly correlated chemical species, and high-leverage reactions in the Thermochemical Network.
(Please note that, as opposed to traditional sequential thermochemistry where the provenance of a given enthalpy of formation is typically a single measurement, the provenances of ATcT enthalpies of formation, which are obtained by analysing and solving a large Thermochemical Network, are normally quite distributed.)