Structural properties and mechanical stability of monoclinic lithium disilicate

The structural, electronic and mechanical properties of monoclinic Li2Si2O5 are explored using density functional theory. Different exchange-correlation functionals are considered and the results are correlated to experimental data. The calculated electronic band structure and density of states indicate that monoclinic Li2Si2O5 has an insulating character with an indirect band gap of 4.98eV. Elastic stiffness coefficients and the bulk, shear and Young's moduli are also calculated. Our calculations predict that Li2Si2O5 is a ductile compound. We show that monoclinic Li2Si2O5 behaves as a specially orthotropic material, meaning that the structure can be masked by the orthorhombic form. (C)2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim