The effect of structural degrees of freedom on bonding and strength characteristics of molybdenum disilicide

Tensile test in MoSi2 with C11b structure along the [001] direction is simulated from first principles using the full-potential linearized augmented plane wave method. A full relaxation of all external and internal structural parameters is performed, and influence of each relaxation process on energetics, strength and behavior of interatomic bonds is investigated in detail. It turns out that for a correct description of the phenomena studied, as e.g. tension–compression asymmetry or the behavior of the interatomic bonds, full relaxation of all structural parameters must be performed.