## 3 Results and Discussion  
### Molar Volumes  
_Solute._ Literature in the HSP context persistently quotes a molar volume of 124.85 cm\({}^{3}\) for LAA. Tracing the source, it becomes evident that this value originates from melt density data that were interpolated to 192 \({}^{\circ}\)C [13; 14]. Apparently, this volume refers to the amorphous-liquid state at a temperature far beyond 25 \({}^{\circ}\)C, suggesting substantial overestimation. To arrive at a less questionable figure, more reliable data were searched. From X-ray crystallographic unit cell dimensions by [PERSON], a value of 103.67 cm\({}^{3}\) at room temperature was derived [15]. Particle density at 25 \({}^{\circ}\)C gave 106.74 cm\({}^{3}\) with the particle purity and crystallinity both unknown [12; 14]. As HSP values generally relate to the liquid state, it is instructive to look also at the LAA partial molar volume (apparent molar volume at infinite dilution) in the solution. By linearly extrapolating aqueous LAA solution density to zero molality at 25 \({}^{\circ}\)C, one obtains partial molar volumes ranging from 102.38 to 106.49 cm\({}^{3}\) (\(n=9\)) with a median (mean) of 105.40 (105.04) cm\({}^{3}\)[16; 17; 18; 19]. All these data point at a molar volume of about 104 cm\({}^{3}\) for highly ordered solid LAA at 25 \({}^{\circ}\)C.  
In [13; 14], the temperature dependence of melt density above 192 \({}^{\circ}\)C is approximated by a modified Rackett equation. Extending this relation way down to 25 \({}^{\circ}\)C yields an estimate for the molar volume of supercooled liquid LAA of 109.85 cm\({}^{3}\), which is about 6% larger compared with the crystalline state. Since the coefficients of the approximate formula lack any indication as to their accuracy, this value should be considered tentative albeit, for instance, analogous polymer data suggest it to be reasonable. Plausibility is corroborated by the fact that, at 25 \({}^{\circ}\)C, amorphous (rubbery or glassy) polymers possess molar volumes that exceed their crystalline counterparts typically by up to 10% [7] (pp. 77-85). The foregoing results are summarized in Table 1, and it is proposed that 109.9 cm\({}^{3}\)/mol might be taken as the most probable value for \(V_{1}\) (25 \({}^{\circ}\)C), while presuming an error of about \(\pm\)4% seems reasonable.  
_Solvents._ All experimental solvent data published [5; 8; 9] relate to liquid phases at temperatures of either 20 \({}^{\circ}\)C or 25 \({}^{\circ}\)C, except methyl hydroperoxide. Values at 20 \({}^{\circ}\)C were also considered adequate since any discrepancies that might arise were rated insignificant within the scope of this study. The only experimental information on methyl hydroperoxide relates to its liquid density at 15 \({}^{\circ}\)C. Reference [12] lists 1.9967 g/cm\({}^{3}\), whereas the traced original source [20; 21] specifies 0.9967 g/cm\({}^{3}\), suggesting a typographic error on data transfer in the past. This drastically impacts \(V_{2}\) (15 \({}^{\circ}\)C), which is 48.2 cm\({}^{3}\) instead of the commonly cited 24.1 cm\({}^{3}\). For 20 \({}^{\circ}\)C, only the calculated theoretical density (0.982 g/cm\({}^{3}\)) is available, leading to \(V_{2}\) (20 \({}^{\circ}\)C) = 48.9 cm\({}^{3}\)[21]. In the absence of further data, this value was adopted for subsequent evaluation.