The stability of atomic intercalated carbon $K_{ 4}$ crystals, XC$_{ 2}$ (X=H, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ga, Ge, As, Se, Br, Rb or Sr) is evaluated by geometry optimization and frozen phonon analysis based on first principles calculations. Although C $K_{ 4}$ is unstable, NaC$_{ 2}$ and MgC$_{ 2}$ are found to be stable. It is shown that NaC$_{ 2}$ and MgC$_{ 2}$ are metallic and semi conducting, respectively.
Categories: cond-mat.mtrl-sci