Elastic properties of solids at high pressure
This review examines the elastic response of solids under load. The definition of isothermal and adiabatic elastic constants of nth order (n ⩾ 2) for the loaded crystal is given. For the case of hydrostatic pressure, two techniques are proposed for calculating the second-, third- and fourth-order elastic constants from the energy—strain and stress—strain relations. As an example, using the proposed approach within the framework of the density functional theory, the second- to fourth-order elastic constants of bcc tungsten are calculated for the pressure range of 0—600 GPa.