 Crystal Structures by R. W. G. Wyckoff

Second edition, volume1, 1963. The magnesium parameters reproduced in Crystallography Open Database entry9008506 are $a=0.320927\mathrm{nm}$ and $c=0.521033\mathrm{nm}$: www.crystallography.net/cod/9008506.html . These independently documented values do not identify which data-book edition accompanied an examination.