Low-energy electron scattering by H2O, H2S, H2Se, and H2Te

Abstract

Articles you may be interested in Dissociative recombination of H + ( H 2 O ) 3 and D + ( D 2 O ) 3 water cluster ions with electrons: Cross sections and branching ratiosWe report elastic differential, integral, and momentum transfer cross-sections for H 2 X molecules ͑X: O, S, Se, and Te͒ obtained at the static exchange level of approximation. The energy range considered was from 2 up to 30 eV for H 2 O and from 5 up to 30 eV for the other molecules. Our calculations were performed with the Schwinger multichannel method with pseudopotentials ͓M. H. F. Bettega, L. G. Ferreira, and M. A. P. Lima, Phys. Rev. A 47, 1111 ͑1993͔͒, combined with a Born closure procedure in order to account for the long-range potential due to the permanent dipole moment of the targets. Our calculated cross-sections for H 2 O and H 2 S are in good agreement with other theoretical results. Agreement with available experimental data is also encouraging. It was found that molecular size plays a crucial role in the scattering process. The influence of heavy and H atoms in the collisions is also discussed. For the integral cross-sections of the heavier molecules we also investigated incident energies below 5 eV, looking for possible shape resonances. Through the symmetry decomposition of the integral cross-sections and the eigenphase sum analysis, we found shape resonances for H 2 S, H 2 Se, and H 2 Te at the B 2 symmetry. For H 2 Te, we have also found a shape resonance at the A 2 symmetry. For all molecules a very broad structure was found at the A 1 symmetry. This is the first work to report such resonances for H 2 Se and H 2 Te.

Calculation of electron-impact rotationally elastic total cross sections for NH3, H2S, and PHLimbachiya1, Vinodkumar2, Mason3 2011Phys. Rev. A363180View full textAdd to dashboardCite

“…Solid line (black), present TCS using the Qmol formaliam); dash line (blue), recent TCS using the SCOP formalism; stars, experimental results of Zecca et al [9]; open diamonds, experimental results of Szmytkowski et al [22]; open circles, experimental results of Jones et al [5]; filled squares, experimental results of Gulley et al [20]. [27]; light pink dotted line, theoretical data of Gupta and Baluja [24]; dash-dot-dot line, theoretical data of Jain and Baluja [26]; long dash-dot line, theoretical data of Varella et al [23]; short-dash-dot, theoretical data of Lengsfield et al [25].…”

“…Electron-impact total cross sections for H 2 S have been measured at low energies by Jones et al (0.02-10 eV) [5], Gulley et al (1-30 eV) [20], and Sokolov and Sokolova (0-10 eV) [21], and at low to high energy by Szmytkowski et al (6-370 eV) [22] and Zecca et al (75-4000 eV) [9]. Low-energy calculations were carried out by Varella et al (5-30 eV) [23] using the Schwinger multichannel method and by Gupta and Baluja (0.025-15 eV) [24] using the R-matrix code. Lengsfield et al [25] have also reported data in the energy range 1-30 eV.…”

Recent advances in the application of the Schwinger multichannel method with pseudopotentials to electron-molecule collisions

“…(51)). For high-symmetry target molecules [55,56] an advantage may be taken from rotational selection rules, so this procedure can be stated on more rigorous grounds (see Sect. 2.2.5).…”

“…First, equation (55) provides a means to estimate the rotational excitation cross sections (for any Γ → Γ transition, not only from the ground state). Second, the RSDCS in equation (57) is particularly useful for highly symmetric targets [55,56] that impose stringent selection rules for dipole-allowed 0 → Γ rotational excitations. As a result, the Born-closure procedure (Eq.…”

Elastic electron scattering from the DNA bases cytosine and thymine

“…Experimental elastic differential cross sections (DCSs) for electron scattering from water have been known for some time [6] and are commonly used in track structure simulations. Only recently have measurements appeared concerning more complex biological molecules, such as formic acid [7], variations of the tetrahydrofuran ring [8,9], alanine [10], and pyrimidine [11].…”