●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 UniversityPhysical 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