Positron binding energies (PBEs) of 41 polyatomic molecules were calculated using the positron-electron correlation-polarization potential (CPP) approach and compared with experimentally measured values. In this approach, the short-range positron-electron potential is modeled using the density-functional expression, whereas the long-range potential is approximated by the attractive polarization potential. The positron-electron CPP model based on local-density approximation yields larger PBEs than experimental values; however, the calculated values can be substantially improved by introducing generalized gradient approximation. We also investigated the conformational dependence of PBEs for representative molecules.
We present the results of quantum wave packet calculations performed to analyze the experimental transition-state spectra for the OH + H2O and OD + D2O reactions based on photodetachment of...
The positron binding
abilities of proline and its hydrated clusters were theoretically
studied using multicomponent molecular orbital (MC_MO) calculations.
Low-lying equilibrium structures of the neutral proline·(H2O)
n
(n = 0–2)
clusters were systematically explored with the aid of global reaction
route mapping code. The positron binding energies were then calculated
for the equilibrium structures. We found that the zwitterionic forms
generally displayed high positron binding energies owing to their
highly polar nature. We also found that nonzwitterionic forms can
exhibit high positron binding energies if the addition of water significantly
increases the total electric dipole moment. These results demonstrate
that the most stable positron-bound proline·(H2O)
n
(n = 1 and 2) structures
are more stable than the most stable neutral structures, which implies
that the attachment of a positron to a neutral hydrated proline cluster
can induce structural changes if the positron–electron annihilation
lifetime is sufficiently long relative to the time scale of nuclear
motion. We also examined the influence of positron binding on the
energy profiles of the proton transfer reactions from the nonzwitterionic
form to the zwitterionic form.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.