<div>Both the computation of, and the uncertainties associated, with gas-phase molar
formation enthalpies are now quite well established for systems comprised of tens of
‘heavy’ atoms chosen from the commonest elements. The same cannot be said for
derived thermochemical quantities such as entropy, heat capacity and an enthalpy
function. Whilst the application of well known statistical thermodynamic relations is
mostly understood, the determination of the uncertainty with which such values can
be obtained has been little studied — apart, that is, for a general protocol devised by
Goldsmith et al. [J. Phys. Chem. A, 2012, 116, 9033–9057]. Specific examples from
that work are explored here and it is shown that their estimates are overly pessimistic.
It is also evident that for some species the calculated thermochemical parameters show
very little variation with either the level of theory, or basis set, or treatment of vibrational modes — this renders the inclusion of such species in databases designed to
validate new methods of limited value.<br></div>
VII. On the determination of the heat-capacity of a thermometer