电子科技大学：《材料设计与计算 Materials Design and Computation》课程教学资源（课件讲稿）MDC 07 Surface calculations（1/2）

20200318-L心-C吸附模型邹剑p. 185432K O士传 传发奇看目 320/202011:5B29A 国了一条清地 Option 1:graphene single atom/molecule So far i only have response from the Group 1 and 4.And I just gave some commonts to the model of Group 4 that is relatively complete and beautiful.Hope that you could get 。 Option 2:experimental observations>physical/chemical some hints from my modification/questions. 3/20202012:32:57 questions>theory model>simulation procedure(step 1: 5 谢谢老师，我们后边再调整下白 structural optimization;step 2:xx properties;step 3:......) 2:50:31M P Group 2.pptx 727题 ⊙士传成助 转发在着三

 Option 1: graphene + single atom/molecule  Option 2: experimental observations → physical/chemical questions → theory model → simulation procedure (step 1: structural optimization; step 2: xx properties; step 3:……)

2D-thin films,surfaces... non-periodic in one direction Surface structures Surface energy Small molecules on surfaces Monolayer and other 2D structures ·Electronic features

 Surface structures  Surface energy  Small molecules on surfaces Monolayer and other 2D structures Electronic features 2D – thin films, surfaces... non-periodic in one direction

Surface structures ·Slab model;: Repetition of slab in z direction The interaction between non-periodic images must be separated by a sufficiently large Vacuum vacuum region; The thickness of the slab must be large enough. 7 Five-layer slab f.x oY今o blk-1

 Slab model;  The interaction between non-periodic images must be separated by a sufficiently large vacuum region;  The thickness of the slab must be large enough. Surface structures

Surface structures (001)Miller plane (111)Miller plane (110)Miller plane ● 的● ●a2 89● ● ● ● ● a ● a a fcc Conventional cell 久hc O0000 ①9④OOOO O00000O 0000000 (100) (111) (110)

Surface structures

Surface structures An asymmetric slab A symmetric slab-to to create size- cancel the artificial Repetition of sl dependent dipole electrostatic field to relax the top three Vacuum layers and keep the bottom two layers Vacuum d12 fixed at bulk positions. Relaxed layers d23 Fixed layers d2 brlk-lika Five-layer slab d23 d23 Relaxed layers Top 3 layers relaxed Vacuum

Surface structures to relax the top three layers and keep the bottom two layers fixed at bulk positions. An asymmetric slab – to create size￾dependent dipole A symmetric slab – to cancel the artificial electrostatic field

Surface structures V2O3(104)surfaces 4.8193A O-termination OV-termination top view side view terminablon 厚度：2.7128A 厚度：5.4255A V408 V8014 厚度：8.1383A V12020 厚度：710.8510 V16026 厚度：13.5638A 厚度：12.8041A V20030 V20O32 7.3226A

O-termination 厚度：2.7128 Å 厚度：5.4255 Å 厚度：8.1383 Å 厚度：10.8510 Å 厚度：13.5638 Å top view side view V4O8 V8O14 V12O20 V16O26 V20O32 V2O3 (104) surfaces 4.8193 Å 7.3226 Å 厚度：12.8041 Å V20O30 Surface structures OV-termination

Surface reconstruction unreconstructed Si(001)e e reconstructed Si(001) Top view Side view m

Surface reconstruction Top view Side view unreconstructed Si(001) reconstructed Si(001)

Surface reconstruction (a) (b tap Diagram of the Si(111)7x7reconstruction on Si(111)from the work of Brommer et al. Large solid circles denote adatoms.The size of the circle indicates the distance of the atoms from the top of the surface.The(7x7)unit cell is outlined

Surface reconstruction Diagram of the Si(111)-7×7 reconstruction on Si(111) from the work of Brommer et al. Large solid circles denote adatoms. The size of the circle indicates the distance of the atoms from the top of the surface. The (7×7) unit cell is outlined

Surface reconstruction 1×7S() 人 80 000000 。0 8

Surface reconstruction

Surface reconstruction 分() Corner Si Sqrt3 5*5 8 8 Adatom 8 8 Rest Si 88 8 0 0 0 Dimer Si 2*2

Rest Si Adatom Corner Si Dimer Si Sqrt 3 Surface reconstruction 2*2 5*5