●a Chapter vil solid State STM下的S晶体 来自于巴基斯坦的黄玉晶体 来自于加拿大魁北克的钙柱石(黄)和透辉石(蓝) 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 6 STM下的Si晶体 来自于巴基斯坦的黄玉晶体 来自于加拿大魁北克的钙柱石（黄）和透辉石（蓝）
●a Chapter vil solid State Early ideas a crystal has flat faces that are at chatacteristic angles to each other o Crystals have symmetry(Kepler)and long range order Spheres and small shapes can be packed to produces regular shapes(Hooke Hauy) 器 灤* 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 7 Early ideas ❖ A crystal has flat faces that are at chatacteristic angles to each other ❖ Crystals have symmetry (Kepler) and long range order ❖ Spheres and small shapes can be packed to produces regular shapes (Hooke, Hauy) ?
●a Chapter vil solid State Group discussion Kepler wondered why snowflakes have 6 corners, never 5 or 7. By considering the packing of polygons in 2 dimensions, demonstrate why pentagons and heptagons shouldn t occur. Empty space not allowed 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 8 Group discussion Kepler wondered why snowflakes have 6 corners, never 5 or 7. By considering the packing of polygons in 2 dimensions, demonstrate why pentagons and heptagons shouldn’t occur. Empty space not allowed
●a Chapter vil solid State All M C Escher works(c)Cordon Art-Baarn-the Netherlands All rights reserved 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 9 All M.C. Escher works (c) Cordon Art-Baarn-the Netherlands. All rights reserved
●a Chapter vil solid State UNIT CELL The LATTICE NP, BASIS/ MOTIF smallest component of the crystal, which when stacked together with pure translational repetition reproduces the CRYSTAL STRUCTURE whole crystal Primitive Cell: simplest cell, contain one lattice point Not necessary have the crystal symmetry 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 10 Primitive Cell: simplest cell, contain one lattice point Not necessary have the crystal symmetry UNIT CELL = The smallest component of the crystal,which when stacked together with pure translational repetition reproduces the whole crystal