Mechanical and Magnetic Properties of Rh and RhH: First-Principles Calculations

Mechanical and magnetic properties of Rh in bcc, fcc structures and RhH in cubic structure are investigated by using first-principles calculations. Theoretical strengths of these structures are given for the first time. The results show that the NaCl-type cubic RhH has a lower bulk modulus and a theoretical strength larger than those of Rh in bcc and fcc structures. A strong magneto-volume effect of a transition from ``low magnetic moment-low cell volume'' to ``high magnetic moment-large cell volume'' is also found for both the bcc and fcc Rh structures as well as RhH.