CONTENTS
General Introduction. Problems on the Theoretical Treatment of Electronic Structures for Extended Aperiodic Systems by Quantum Chemical Calculations / p1
References / p6
Chapter1. Calculations of Polymer Systems with Local Aperiodic Part:Elongation Method with Supercell Method / p7
　1.1.Introduction / p8
　1.2.Method / p10
　1.3.Results and Discussion / p17
　1.4.Summary / p26
　References / p27
Chapter2. Electronic Structures of Large, Extended, Nonperiodic Systems:Cluster Series of Polymer and Molecular Stacking on Surface / p28
　2.1.Introduction / p29
　2.2.Method / p32
　2.3.Results and Discussion / p46
　2.4.Summary / p68
　References / p69
Chapter3. Interface and Local Defect States in a Polymer:Periodicity in Electronic States of a Nonperiodic Polymer / p70
　3.1.Introduction / p71
　3.2.Method / p75
　3.3.Results and Discussion / p84
　3.4.Summary / p105
　References / p106
Chapter4. Theoretical Approach for Locally Perturbed Periodic Systems:Development of Ab Initio Crystal Elongation Method / p107
　4.1.Introduction / p108
　4.2.Method / p112
　4.3.Results and Discussion / p120
　4.4.Summary / p130
　References / p131
General Conclusion. Progresses on the Theoretical Treatment of Electronic Structures for Extended Aperiodic Systems by Quantum Chemical Calculations / p133