L. Desgranges et al., INTERLAYER INTERACTIONS IN M(OH)(2) - A NEUTRON-DIFFRACTION STUDY OF MG(OH)(2), Acta crystallographica. Section B, Structural science, 52, 1996, pp. 82-86
Magnesium hydroxide, Mg(OH)(2) M(r) = 58.3, trigonal, <P(3)over bar m1
>, a = 3.148 (1), c = 4.779 (2) Angstrom, V = 41.015 Angstrom(3), D-x
= 2.36 g cm(-3) at room temperature; a = 3.145 (1), c = 4.740 (2) Angs
trom, V = 40.602 Angstrom(3), D-x = 2.39 g cm(-3) at 70 K; Z = 1, lamb
da = 0.8330 (5) Angstrom, mu = 1.78 cm(-1), F(000) = 9.503 fm; final R
= 2.42, wR = 2.40, S = 3.22 for 82 unique reflections at room tempera
ture; R = 1.84, wR = 1.82, S = 2.54 for 81 unique reflections at 70 K.
Refinements have been carried out using anisotropic thermal coefficie
nts for all atoms. To interpret the very large thermal motion of the H
atom, subsequent refinements have been carried out with an anharmonic
model and with a three-site split-atom model, and results are compare
d with those previously reported for Ca(OH)(2). By comparing the inter
atomic distances O ... O, H ... H and H ... O in the interlayer spacin
g of Mg(OH)(2) and Ca(OH)(2), as well as their temperature dependence,
the nature and the strength of interlayer interactions in both compou
nds are discussed.