Hydrogen thermal motion in calcium hydroxide: Ca(OH)2

Calcium hydroxide, Ca(OH) 2 , M r =74, trigonal, P3m1, a=3.589 (8), c=4.911 (14) A, V=54.8 (4) A 3 , D x =2.26 cm -1 at room temperature, Z=1, λ=0.8330 (5) A, μ=1.195 cm -1 , F(000)=9.028 fm, final R=0.018, wR=0.019, for 105 unique reflections, at 80 K; R=0.025, wR=0.027, for 211 unique reflections, at room temperature. The structure of calcium hydroxide has been refined using neutron data collected at 80 K and at room temperature. Thermal motion of the H atom has been refined with anharmonic thermal-motion parameters at room temperature and at 80 K