The mechanism for the 3 x 3 distortion of Sn/ge (111)

S. de Gironcoli, S. Scandolo, G. Ballabio +2

We show that two distinct $3\times 3$ ground states, one nonmagnetic, metallic, and distorted, the other magnetic, semimetallic (or insulating) and undistorted, compete in $\alpha$-pha…