Complex Energies and Transition-Dipoles for the Uracil anion Shape-type Resonances from stabilization curves via Padé

Abstract

Absorption of slow moving electrons by neutral ground state nucleobases have been known to produce resonance, metastable, states. There are indications that such metastable states may play a key-role in DNA/RNA damage. Therefore, herein, we present an ab-initio, non-Hermitian investigation of the resonance positions and decay rates of the low lying shape-type states of the uracil anion. In addition, we calculate the complex transition dipoles between these resonance states. We employ the resonance via Padé (RVP) method to calculate these complex properties from real stabilization curves by analytical dilation into the complex plane. This method has al-ready been successfully applied to many small molecular systems and herein we present the first application of RVP to a medium-size system. The presented resonance energies are converged with respect to the size of the basis set and compared with previous theoretical works and experimental findings. Complex transition dipoles between the shape-type resonances are computed using the energy-converged basis set. The ability to calculate ab-initio energies and lifetimes of biologically relevant systems opens the door for studying reactions of such systems in which autoionization takes place. While the ability to also calculate their complex transition dipoles open the door for studying photo induced dynamics of such biological molecules.

Tuning quantum–classical correspondence for atomic and molecular systems in a cavity

“…One may think here e.g. of molecular anions such as molecular nitrogen anion [33] in its ground state, or uracil anion in its ground and excited states which we studied recently [34], or exotic atomic anions such as positronium negative anion that were observed in bombardment of slow positrons onto a Na-coated W surface [35]. Note however that, based on our above derivation for the weak coupling regime, as is increased the coupling between the bound states and resonances with the continuum of the molecules will be increased.…”