Elastic electron scattering by fullerene, C60

We report cross sections for elastic scattering of low-energy electrons by fullerene, C60, calculated within the static-exchange approximation. The calculations are carried out via the Schwinger multichannel (SMC) method, equivalent in this case to the standard Schwinger variational principle. Combining the high parallel efficiency of the SMC method with a quadrature specially adapted to the high symmetry of C60 facilitates the most demanding step of the calculation and so permits the use of a large basis set. We analyze the structure of the cross section with reference to a simple spherical-shell model, and we compare our results to prior measurements and calculations

Electron scattering in ethene: Excitation of the ã 3B1u state, elastic scattering, and vibrational excitation

Experimental and calculated absolute differential cross sections for the scattering of low-energy electrons from ethene are presented. Emphasis is on the excitation of the ã 3B1u 3(pi,pi*) state, but selected elastic and vibrational excitation cross sections are also given. In contrast to earlier calculations, which were nearly a factor of 2 too large, the present calculation agrees very well with the experimental triplet excitation cross section in the threshold region. The improvement is due primarily to the inclusion of target polarization, which results in proper positioning of the pi* resonance, whose high-energy tail dominates the triplet state excitation near threshold. The present experimental elastic cross sections agree very well with recent calculations taking into account target polarization

Absolute angle-differential elastic cross sections for electron collisions with diacetylene

We report measured and calculated differential elastic cross sections for collisions of low-energy electrons with diacetylene (1,3-butadiyne). A generally satisfactory agreement between theory and experiment has been found. The calculated cross sections provide interesting insight into the underlying resonant structure

Vibrational excitation of water by electron impact

Experimental and calculated differential cross sections (DCSs) for electron-impact excitation of the (010) bending mode and unresolved (100) symmetric and (001) antisymmetric stretching modes of water are presented. Measurements are reported at incident energies of 1–100 eV and scattering angles of 10°–130° and are normalized to the elastic-scattering DCSs for water determined earlier by our group. The calculated cross sections are obtained in the adiabatic approximation from fixed-nuclei, electronically elastic scattering calculations using the Schwinger multichannel method. The present results are compared to available experimental and theoretical data

Low-energy electron scattering by C_2HF_5

We report elastic and electronically inelastic cross sections for low-energy electron scattering by pentafluoroethane, C_2HF_5. Our calculations were performed using the Schwinger multichannel method. For elastic scattering, we calculated integral, differential, and momentum transfer cross sections for energies from 5 to 50 eV. In the inelastic case, we obtained integral and differential cross sections for electron-impact excitation of the 1 1,3A[prime] and 2 1,3A[prime] excited states at the three-channel level of approximation. At higher energies, the elastic differential cross sections are quite similar to existing theoretical results for C_2F_6. Limited electronic-structure calculations were carried out to explore the dissociation behavior of the excited states

Low-energy electron scattering from C_4H_9OH isomers

We present differential, integral, and momentum-transfer cross sections for elastic scattering of low-energy electrons by three butanol isomers, isobutanol, t-butanol, and 2-butanol. Our results were calculated with the Schwinger multichannel method in the static-exchange plus polarization approximation for collision energies from 1 to 50 eV. The present results are compared with previous calculations and measurements for the remaining C_4H_9OH isomer, n-butanol [Khakoo et al., Phys. Rev. A 78, 062714 (2008)]. Distinctive behavior is observed in the differential cross sections at collision energies between 5 and 10 eV. In particular, whereas n-butanol exhibits an f-wave scattering pattern, the other isomers exhibit d-wave behavior. A similar pattern is found in the related alkanes when comparing straight-chain versus branched isomers. We discuss the possible connection of this behavior to shape resonances that influence the scattering

Low-energy electron scattering by N2O

We present elastic integral, differential, and momentum-transfer cross sections for electron collisions with N2O. We show that, with a slight modification of a method of incorporating polarization effects proposed recently by us [Winstead, McKoy, and Bettega, Phys. Rev. A 72, 042721 (2005)] along with a flexible one-particle basis set, we can reproduce features in the experimental data that were not reproduced by earlier calculations. We also find evidence of a Ramsauer-Townsend minimum, which our calculation places at about 0.2 eV

Elastic scattering of low-energy electrons by benzene

We present elastic cross sections obtained from ab initio calculations for low-energy electron scattering by benzene, C6H6. The calculations employed the Schwinger multichannel method as implemented for parallel computers within both the static-exchange and static-exchange-polarization approximations. We compare our results with other theoretical calculations and with available experimental data. In general, agreement is good

The Relation Between Parenting Beliefs, Behaviors, and Acculturation on the Social Skills of Prekindergarten Hispanic Children

Research shows that social skills are a critical component of children’s development and related to children’s academic success. Conversely, problem behaviors are correlated to negative outcomes later in life for children such as lower academic achievement and juvenile and adult criminality. Certain parenting beliefs and behaviors have been found to relate to fewer problem behaviors in children, and an increase in social skills. However, existing research has focused mostly on the parenting behaviors and social outcomes in children using Anglo-American samples. Little is known about the relation of parenting behaviors and beliefs to the development of social skills in Hispanic families. Using the HOME (Home Observation for Measurement of the Environment), the Parental Modernity Scale, and the Bidimensional Acculturation Scale (BAS), measures of the relation and predictive ability of parenting behaviors, beliefs and acculturation to social skills in children as measured by the Social Skills Rating System (SSRS) are calculated. Findings suggest that the progressive subscale scores from the parental modernity scale and the family companionship subscale from the HOME are predictive of higher scores on the SSRS socials skills scale in prekindergarten Hispanic children. Acculturation was not related to higher social skills scores or fewer problem behaviors in children. The results are discussed in light of previous research and existing knowledge on what the results mean for the parenting behaviors and beliefs of Hispanics. (75 pages