(* GaAs4.m *) (* Two (110) planes, illustrating the surface relaxation of the first and second layers. Relaxation atomic positions taken from LEED studies (Phys Rev B, 42, 8592 (1990)) *) (* Alastair McLean *) (* mclean@mnbsun.phy.queensu.ca *) (* 12 February 1992 *) (* Copyright 1992 Permission is granted to modify and/or make copies of this file for any purpose other than direct profit, or as part of a commercial product, provided this copyright notice is left intact. *) Picture = Graphics3D[ {PointSize[0.035], (* This is the third layer down *) (* As atoms *) GrayLevel[0.0], Point[{0.0, 0.0, 0.0}], Point[{0.7, 0.0, 0.0}], Point[{1.4, 0.0, 0.0}], Point[{2.1, 0.0, 0.0}], Point[{0.0, 1.0, 0.0}], Point[{0.7, 1.0, 0.0}], Point[{1.4, 1.0, 0.0}], Point[{2.1, 1.0, 0.0}], (* bonds in the first layer *) {Line[{{0.0, 0.0, 0.0}, {0.35, 0.23, 0.01}}]}, {Line[{{0.35, 0.23, 0.01}, {0.7, 0, 0}}]}, {Line[{{0.7, 0, 0}, {1.05, 0.23, 0.01}}]}, {Line[{{1.05, 0.23, 0.01}, {1.4, 0.0, 0.0}}]}, {Line[{{1.4, 0.0, 0}, {1.75, 0.23, 0.01}}]}, {Line[{{1.75, 0.23, 0.01}, {2.1, 0.0, 0}}]}, {Line[{{0.00, 1.0, 0.0}, {0.35, 1.23, 0.01}}]}, {Line[{{0.35, 1.23, 0.01}, {0.7, 1.0, 0}}]}, {Line[{{0.70, 1.0, 0}, {1.05, 1.23, 0.01}}]}, {Line[{{1.05, 1.23, 0.01}, {1.4, 1.0, 0.0}}]}, {Line[{{1.40, 1.0, 0}, {1.75, 1.23, 0.01}}]}, {Line[{{1.75, 1.23, 0.01}, {2.1, 1.0, 0}}]}, (* Ga atoms *) GrayLevel[0.6], Point[{0.35, 0.23, 0.01}], Point[{1.05, 0.23, 0.01}], Point[{1.75, 0.23, 0.01}], Point[{0.35, 1.23, 0.01}], Point[{1.05, 1.23, 0.01}], Point[{1.75, 1.23, 0.01}], (* This is the second layer down *) (* As atoms *) GrayLevel[0.0], Point[{0.35, 0.50, 0.47}], Point[{1.05, 0.50, 0.47}], Point[{1.75, 0.50, 0.47}], Point[{0.35, 1.50, 0.47}], Point[{1.05, 1.50, 0.47}], Point[{1.75, 1.50, 0.47}], (* bonds in the second layer *) {Line[{{0.00, 0.73, 0.35}, {0.35, 0.50, 0.47}}]}, {Line[{{0.35, 0.50, 0.47}, {0.70, 0.73, 0.35}}]}, {Line[{{0.70, 0.73, 0.35}, {1.05, 0.50, 0.47}}]}, {Line[{{1.05, 0.50, 0.47}, {1.40, 0.73, 0.35}}]}, {Line[{{1.45, 0.73, 0.35}, {1.75, 0.50, 0.47}}]}, {Line[{{1.75, 0.50, 0.47}, {2.10, 0.73, 0.35}}]}, {Line[{{0.00, 1.73, 0.35}, {0.35, 1.50, 0.47}}]}, {Line[{{0.35, 1.50, 0.47}, {0.70, 1.73, 0.35}}]}, {Line[{{0.70, 1.73, 0.35}, {1.05, 1.50, 0.47}}]}, {Line[{{1.05, 1.50, 0.47}, {1.40, 1.73, 0.35}}]}, {Line[{{1.40, 1.73, 0.35}, {1.75, 1.50, 0.47}}]}, {Line[{{1.75, 1.50, 0.47}, {2.10, 1.73, 0.35}}]}, (* Ga atoms *) GrayLevel[0.6], Point[{0.00, 0.73, 0.35}], Point[{0.70, 0.73, 0.35}], Point[{1.40, 0.73, 0.35}], Point[{2.10, 0.73, 0.35}], Point[{0.00, 1.73, 0.35}], Point[{0.70, 1.73, 0.35}], Point[{1.40, 1.73, 0.35}], Point[{2.10, 1.73, 0.35}], (* third layer-second layer bonds *) GrayLevel[0.0], {Line[{{0.35, 0.23, 0.01}, {0.35, 0.50, 0.47}}]}, {Line[{{1.05, 0.23, 0.01}, {1.05, 0.50, 0.47}}]}, {Line[{{1.75, 0.23, 0.01}, {1.75, 0.50, 0.47}}]}, {Line[{{0.35, 1.23, 0.01}, {0.35, 1.50, 0.47}}]}, {Line[{{1.05, 1.23, 0.01}, {1.05, 1.50, 0.47}}]}, {Line[{{1.75, 1.23, 0.01}, {1.75, 1.50, 0.47}}]}, {Line[{{0.00, 0.73, 0.35}, {0.0, 1.0, 0.0}}]}, {Line[{{0.70, 0.73, 0.35}, {0.7, 1.0, 0.0}}]}, {Line[{{1.40, 0.73, 0.35}, {1.4, 1.0, 0.0}}]}, {Line[{{2.10, 0.73, 0.35}, {2.1, 1.0, 0.0}}]} }] Null