Full-configuration-interaction study of the metal-insulator transition in model systems: Peierls dimerization in H n rings and chains

The Peierls dimerization with associated metal-insulator transition is studied in a model systems with ab initio methods. These are chains and rings HN of hydrogen atoms treated by full CI using a minimal STO-3G atomic orbital basis for N = 6 to N = 14. We describe and discuss in some detail the potential energy surface governing Peierls’ dimerization and study the localization tensor as the indicator of the metal-insulator transition. Results for linear chains and rings are compared.