Carl Winstead

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The authors report results from computational studies of the interaction of low-energy electrons with the purine bases of DNA, adenine and guanine, as well as with the associated nucleosides, deoxyadenosine and deoxyguanosine, and the nucleotide deoxyadenosine monophosphate. Their calculations focus on the characterization of the pi* shape resonances(More)
Measured and calculated differential cross sections for elastic ͑rotationally unresolved͒ electron scattering from two primary alcohols, methanol ͑CH 3 OH͒ and ethanol ͑C 2 H 5 OH͒, are reported. The measurements are obtained using the relative flow method with helium as the standard gas and a thin aperture as the collimating target gas source. The relative(More)
Continuing attention has addressed incorportation of the electronically dynamical attributes of biomolecules in the largely static first-generation molecular-mechanical force fields commonly employed in molecular-dynamics simulations. We describe here a universal quantum-mechanical approach to calculations of the electronic energy surfaces of both small(More)
Recent measurements [R. Panajotovic, M. Jelisavcic, R. Kajita, T. Tanaka, M. Kitajima, H. Cho, H. Tanaka, and S. J. Buckman, J. Chem. Phys. 121, 4559 (2004)] and calculations [C. Trevisan, A. E. Orel, and T. N. Rescigno, Phys. Rev. A 70, 012704 (2004)] of the elastic electron cross section for C(2)F(4) differ materially from our earlier calculations [C.(More)
Total, elastic, and inelastic cross sections for positron and electron collisions with tetrahydrofuran We describe the development of a consistent set of low-energy electron collision cross sections for trifluoromethane, CHF 3. First-principles calculations are used to obtain key elastic and inelastic cross sections. These are combined with literature(More)
We report a combined experimental and theoretical investigation of dissociative electron attachment (DEA) to the nucleobase uracil. Using ion momentum imaging experiments employing a DEA reaction microscope we have measured 3-dimensional momentum distributions of specific anionic fragments following DEA to uracil by 6 eV electrons. From the measured anion(More)
We report calculated cross sections for elastic and electronically inelastic collisions of low-energy electrons with sulfur hexafluoride, SF(6). Elastic cross sections are computed within the fixed-nuclei approximation, with polarization effects incorporated. Inelastic cross sections for nine low-lying states are computed in a few-channel approximation. We(More)