Resonating Hartree-Fock approach for electrons confined in two dimentional square quantum dots

We studied the applicability of the resonating unrestricted Hartree-Fock (res-UHF) approach for configuration interaction (CI) by considering the electronic structure of two electrons confined in a two-dimensional (2D) square quantum dot (SQD). The UHF solutions for the SQD are nonorthogonal mutually but are appropriate for the basis functions for the res-UHF CI calculation because they represent the conceivable electron-spin configurations rationally. Consequently, the res-UHF CI using these UHF non-orthogonal solutions has an advantage for narrowing down the number of employed Slater determinants, although at the expense of the orthogonality among the Slater bases.