Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1516483 | Journal of Physics and Chemistry of Solids | 2012 | 4 Pages |
The mechanical stabilities of K4 carbon and K4-like NaC2 have been studied by performing first-principle calculations. Total energies as functions of isotropic deformations and volume-conserving tetragonal and trigonal deformations have been calculated. For K4 carbon, the total energy shows a minimum for isotropic and trigonal deformations, but exhibits maxima for tetragonal deformation. In contrast, the total energy of K4-like NaC2 shows a minimum under all three deformations. These results indicate that K4 carbon is not a metastable phase, but that K4-like NaC2 is a metastable phase. In addition, the heat of formation of K4-like NaC2 is discussed.
► Mechanical stability of K4 carbon and K4-like NaC2 has been studied. ► K4 carbon is not a metastable phase. ► K4-like NaC2 is a metastable phase.