Unveiling the strong coulomb interaction effect on electronic structures and mechanical properties of C 4 AF

Abstract There are works have reported the crystal structures and mechanical properties of ferrite cement (C 4 AF) at the atomic scale with deviation owing to the omission of the Coulomb interaction effect ( U eff ) between 3 d electrons of Fe in C 4 AF. In this work, the DFT+ U method was used to evaluate its effect on their electronic structures and mechanical properties of C 4 AF with two different phases I2mb (C 4 AF‐ I ) and Pnma (C 4 AF‐ P ). The FeO bonds of the two phases are all weaker and display U eff due to the presence of Fe ions. The mechanical properties of C 4 AF calculated using DFT+ U method significantly differ from those obtained without considering U eff , in which the former shows lower inferior mechanical properties than the latter. This work presents a comparative study the effect of Coulomb interaction to the internal electronic structures and mechanical properties, which will pave the way for designing high hydration reaction cement and high toughness materials.