Quantum dynamics calculation of the annihilation spectrum for positron–proline scattering

Publication date: Available online 1 December 2018Source: Computational and Theoretical ChemistryAuthor(s): Yutaro Sugiura, Kento Suzuki, Shoichi Koido, Toshiyuki Takayanagi, Yukiumi Kita, Masanori TachikawaAbstractThe annihilation spectrum for positron scattering by the amino acid proline was calculated using local complex potential theory combined with the time-dependent quantum wave packet method. Two nuclear degrees of freedom associated with the motion of the carboxyl group proton were considered in the dynamics. The positronic potential energy surface and positron–electron contact densities were calculated using ab initio multi-component molecular orbital theory. The calculated annihilation spectrum contained several vibrational resonance peaks, which allowed the positron binding energies to be estimated. We also observed a resonance with a very small contribution of zwitterionic proline via proton transfer.Graphical abstract

Source: Computational and Theoretical Chemistry - December 1, 2018 Category: Chemistry Source Type: research