Neutron Diffraction Study of Calcium Hydroxide

Single crystal neutron diffraction measurements on Ca(OH)2 at 20°C and —140°C confirm the x-ray structure and the hydrogen positions previously postulated. Refinement of the neutron data by Fourier and least squares procedures yields a detailed description of the thermal motions. The amplitudes of the motion of the hydrogen atoms are compared with those deduced from infrared and Raman studies. The O–H distance, after allowance for asymmetric thermal motion, is 0.984 A.