### Abstract

Different computational methods are employed to evaluate elastic (rotationally summed) integral and differential cross sections for low energy (below about 10 eV) positron scattering off gas-phase C_{2}H_{2} molecules. The computations are carried out at the static and static-plus-polarization levels for describing the interaction forces and the correlation-polarization contributions are found to be an essential component for the correct description of low-energy cross section behavior. The local model potentials derived from density functional theory (DFT) and from the distributed positron model (DPM) are found to produce very high-quality agreement with existing measurements. On the other hand, the less satisfactory agreement between the R-matrix (RM) results and measured data shows the effects of the slow convergence rate of configuration-interaction (CI) expansion methods with respect to the size of the CI-expansion. To contrast the positron scattering findings, results for electron-C_{2}H_{2} integral and differential cross sections, calculated with both a DFT model potential and the R-matrix method, are compared and analysed around the shape resonance energy region and found to produce better internal agreement.

Original language | English |
---|---|

Pages (from-to) | 425-434 |

Number of pages | 10 |

Journal | Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms |

Volume | 266 |

Issue number | 3 |

DOIs | |

State | Published - Feb 2008 |

### Keywords

- 31.25.v
- 34.80.Bm
- 34.85.+x
- Computed angular distributions for e/e scattering
- Electron-molecule scattering
- Molecular gases
- Positron-molecule scattering
- Quantum calculations

## Fingerprint Dive into the research topics of 'Correlation-polarization effects in electron/positron scattering from acetylene: A comparison of computational models'. Together they form a unique fingerprint.

## Cite this

*Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms*,

*266*(3), 425-434. https://doi.org/10.1016/j.nimb.2007.12.019