A picture of the quantum mechanical coordination along the (110)-plane in brucite is shown below.
Each hydroxy group shares a face with the hydroxy group of the next layer. The (3, -1) bond critical point lies between two the two hydrogen atoms of each hydroxy group.
Again this gives a coordination number of 4 for hydrogen. You get the same coordination number for Ca(OH)2 using a STO 3G basis set.
Last Updated: 26 October 1996