Table 5.

Compilation of existing measurements of the molar volume of solid deuterium.

References	Sample (% para)	Temperature	Measured molar volume (cm3/mole)	Molar volume corrected to 18.7 Ka (cm3/mole)
Mucker et al. (1965) [62]	33%	13 K	20.08 (±0.12)b	20.39±0.12
neutron powder diffraction	2%	13 K	20.08 (±0.12)b	20.41±0.12
Schuch and Mills (1966) [60]	33 – 65%c	1..5 K	19.80±0.20d	20.28±0.20
x-ray powder diffraction
Bostanjoglo and Kleinschmidt (1967)	33%	4.2 K	19.90±0.11	20.37±0.11
[61] electron powder diffraction
Mucker et al. (1968) [63]	3%	12.9 K	20.02 (±0.12)e	20.33±0.12
neutron powder diffraction	33%	10.2 K	19.91 (±0.12)e	20.33±0.12
	63%	2.0 K	19.74 (±0.12)e	20.32±0.12
	80%	10.5 K	19.84 (±0.12)e	20.37±0.12
	80%	4.2 K	19.85 (±0.12)e	20.46±0.12
Nielsen (1973) [64]	2%	5.0 K	19.94 (±0.03)f	20.39±0.04
single-crystal neutron diffraction
Yarnell et al. (1975) [65]	2%	4.2 K	19.994±0.013	20.45±0.03
neutron powder diffraction

^aThis calculation is done in three steps. First, the measured molar volume is corrected according to the prescription of Driessen et al. [14] to the value corresponding to zero percent para at the same temperature. Next, the temperature correction is made to 18.7 K using the analytic expression for the linear thermal expansion by Nielsen [64]. Finally, the o-D₂ volume is corrected at 18.7 K to that of n-D₂ again according to reference [14]. We assume a error of ±0.03 cm³/mole for this calculation. The accuracy limit in column 5 is taken as the square root of the sum of the squares of the error limit in column 4 and the assumed error in the temperature correction.

^bEstimated error assumes ±0.005 A uncertainty in a and ±0.005 in c/a.

^cNo trend was observed in the hcp molar volume with para concentration.

^dWe set the uncertainty limit equal to the observed data scatter.

^eThe ±0.6% volume error was calculated from the quoted ±0.2% uncertainty in the nearest neighbor distance.

^fThe ±0.15% volume error was calculated with an assumed 0.05% uncertainty for the lattice parameter measurements.