First-principles atomic level stresses: application to a metallic glass under shear

<jats:title>Abstract</jats:title> <jats:p>Unlike crystalline alloys, metallic glasses (MGs) do not possess distinctive defects but exhibit a highly heterogeneous response to shear deformation. The difficulties in describing such non-uniform behaviour hamper the prediction of the mechanical properties of MGs. Using the first-principles athermal quasi-static shear simulation on a CuZr glass, we investigate the mechanical responses of various atomic-level parameters, such as the first-principles atomic stresses and electronic properties (an atomic charge, chemical bonds, etc), and their correlations. We find that the atomic von Mises stress is correlated with a <jats:inline-formula> <jats:tex-math> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi>D</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>min</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="mrxacf2daieqn1.gif" xlink:type="simple"/> </jats:inline-formula> parameter, which is commonly employed and also serves as a unique measure of the degree of non-uniform responses. We also show little correlation between the mechanical and electronic properties during the relaxation process, while we perceive a high correlation between the change in chemical and topological bonds. We discuss the physical insights behind these correlations.</jats:p>