Phonon dispersion curves for three new MoS₂ type monolayers.

Using ab initio calculations based on density functional theory, we obtained new structures for MoS₂ type monolayers: NbS₂, MoP₂ and NbP₂, not previously reported in the literature. These proposed structures were relaxed to their minimum energy configuration. Then, we calculated the phonon dispersion curves for each one of them. We exhibit the differences with respect of MoS_2. The Quantum-Espresso package [1] was used with norm conserving pseudo potentials.

[1] Giannozzi P, Baroni S, Bonini N, Calandra M, Car R, Cavazzoni C, et al. Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials. J Phys Condens Matter 2009; 21: 395502-19.