Electron densities in hydrogen bonds; lizardite-1T

The interlayer O-H...O contact in lizardite is chosen as an example of the simple strong hydrogen bond. Details of the electron density distribution demonstrate that the interatomic region of the hydrogen bond is considerably depleted in electron density. This partial positive charge near the H atom situated between two electronegative atoms is characteristic of an effective hydrogen bond. A comparison of electron densities within hydrogen bonds in lizardite and brucite shows that the former represents a simple dipole-to-ion interaction, whereas the latter shows dipole-to-dipole interaction in a head-to-tail arrangement. The total energy of the hydrogen bond is 28.121 and 4.203-5.728 Kj/mol for lizardite and brucite, respectively. The evaluation of the deformation of the electron density due to interlayer bonding qualitatively accounts for the shifts in OH stretching frequencies in IR spectra.