Pseudo-Jahn-Teller Effect in Ferrohemoglobin Due to (3d)⁶–(3d)⁵(4p) Interaction by an A_2u Vibrational Mode

Abstract

The triggering mechanism at the transition from the T-conformation to R-conformation in the Hemoglobin is attributed to the pseudo-Jahn-Teller effect resulting from the intra-atomic (3d)⁶–(3d)⁵(4p) interaction by an A_2u vibrational mode. The general formula for this effect in ion-porphyrins as well as metalloporphyrins is given by the closure approximation. The explicit adiabatic potentials of the iron for the tertiary two conformations (t- and r-conformation) are given.