@article {31,
	title = {A new low-energy crystal structure for silicon},
	journal = {Phys. Rev. Lett.},
	volume = {67},
	year = {1991},
	pages = {715},
	author = {L. L. Boyer and E. Kaxiras and J.L. Feldman and J.Q. Broughton and M.J. Mehl}
}
