Abstract
Different stacking arrangements of layered crystals are studied with the use of the ab initio pseudopotential density-functional method. The total energies, lattice constants, electron energy band structures and density of states, as well as phonon frequencies are calculated for the possible bulk structures obtained by full relaxations starting from different initial atomic configurations of ABAB (or ABCABC)⋅⋅⋅ layer stacking. Two stable structures, one semiconductor and the other metal, are obtained, which have lower total energies comparing with those of the structures proposed previously. Our calculations show that except for these two structures, all the structures we studied, including the structures proposed previously, have imaginary phonon frequencies corresponding to the relative, parallel motion of the adjacent layers, indicating the instability of the layer stacking in these structures.
- Received 8 October 2002
DOI:https://doi.org/10.1103/PhysRevB.69.024110
©2004 American Physical Society