Effects of H on Electronic Structure and Ideal Tensile Strength of W: A First-Principles Calculation

We investigate the structure, energetics, and the ideal tensile strength of tungsten (W) with hydrogen (H) using a first-principles method. Both density of states (DOS) and the electron localization function (ELF) reveal the underlying physical mechanism that the tetrahedral interstitial H is the most energetically favorable. The first-principles computational tensile test (FPCTT) shows that the ideal tensile strength is 29.1 GPa at the strain of 14% along the 001 direction for the intrinsic W, while it decreases to 27.1 GPa at the strain of 12% when one impurity H atom is embedded into the bulk W. These results provide a useful reference to understand W as a plasma facing material in the nuclear fusion Tokamak.