Carbon-doped K4 nitrogen: A novel high energy density material

The structural stability of K4 nitrogen was studied by performing first-principles calculations. The total energy as a function of isotropic deformations and volume-conserving tetragonal and trigonal deformations was calculated. The total energy was a minimum under all three deformations, suggesting that K4 nitrogen is a mechanically stable phase. However, the results of phonon dispersion calculations indicated that it is dynamically unstable. Our results also indicated that structural stability can be maintained by doping the K4 nitrogen lattice with carbon, and that the resulting material will be a promising candidate as a high energy density material.