●a Chapter vil solid State or if you dont start from an atom 20218/21 Chemistry Departme nt of Fudan University 16
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 16 - or if you don’t start from an atom
●a Chapter vil solid State This is not a unit cell even though they are all the same -empty space is not allowed 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 17 This is NOT a unit cell even though they are all the same - empty space is not allowed!
●a Chapter vil solid State In 2D. this is a unit cell In 3D. it is Not 20218/21 Chemistry Departme nt of Fudan University 18
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 18 In 2D, this IS a unit cell In 3D, it is NOT
●a Chapter vil solid State Translation Tmnp=ma+nb pc Unit Cell choice By convention the unit cell is chosen so that it is as sma∥ as possibl/ e while reflecting the fu∥ symmetry of the lattice 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 19 Translation T ma nb pc mnp = + + Unit Cell choice By convention the unit cell is chosen so that it is as small as possible while reflecting the full symmetry of the lattice
●a Chapter vil solid State Definitions 1. The unit cell which shows the full symmetry of the structure " The smallest repeat unit of a crystal structure in 3 1 The unit cell is a box With ·3 sides-a.b.c 3 angles-α,β,y y X 20218/21 Chemistry Departme nt of Fudan University
Physical ChemistryI Chapter VII Solid State 2021/8/21 Chemistry Department of Fudan University 20 Definitions 1. The unit cell “The smallest repeat unit of a crystal structure, in 3D, which shows the full symmetry of the structure” The unit cell is a box with: • 3 sides - a, b, c • 3 angles - , ,