A comparative study of the anisotropy of lattice strain induced in the crystals of L-serine by cooling down to 100 K or by increasing pressure up to 4.4 GPa

The anisotropy of lattice strain in the crystals of L-serine (P2(1)2(1)2(1), at ambient conditions a = 5.615(1) angstrom, b = 8.589(2) angstrom, c = 9.346(2) angstrom) on cooling down to 100 K and with increasing hydrostatic pressure up to 4.4 GPa was compared with each other and also with the results previously obtained for the polymorphs of glycine. On cooling, the structure expanded slightly along the crystallographic a-direction, compression along the crystallographic b- and c-directions (normal to the chains of the serine zwitter-ions) was very similar. With increasing pressure, the same structure compressed in all the crystallographic directions, linear strain along c-axis was the largest, linear strain along a-axis - the smallest, linear compression along the b-axis with increasing pressure was slightly larger than that along the a-axis. The different anisotropy of lattice strain of the same structure on cooling and under pressure could be correlated with different response of intermolecular hydrogen bonds to these two scalar actions.