COMPLEX DIAGONAL SHIFT FORMULA (CDSF) IN SCF ITERATIVE PROCESS

In this paper, we extend the diagonal shift formula (DSF) to complex diagonal shift formula (CDSF) in a complex field, and give the theoretical proof of convergence. Meanwhile, when the variable degenerates from complex to real, the CDSF will become DSF, which indicates that the former is indeed the extension of the latter. The CDSF has already been applied to MNDO/GIAO and INDO/GIAO calculations of NMR shielding constants which involve calculations of the complex Fock matrix. Overall convergence of iterative process manifests that the CDSF is an effective method of complex matrix iterations.