Negative linear compressibility from rotating rigid units

The possibility of achieving the anomalous property of negative linear compressibility through a mechanism involving the rotations of rigid units is presented and discussed through analytical modelling. It is shown that some rotating rigid units with particular geometric features and connectivities will expand rather than contract in certain directions when a hydrostatic pressure is applied. The conditions required for this anomalous property to be achieved via rotations are elucidated in terms of specific geometric and structural requirements as well as their Poisson's ratio and stiffness properties. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim