Effects of two vibrational modes in the dissociative electron attachment to CF3Cl

We present a study of multimode effects in dissociative electron attachment to CF3Cl molecules using a time-independent version of the local complex potential theory. Symmetric stretch C-Cl vibrations v3 and symmetric deformation (or so-called umbrella) vibrations v2 are included. The neutral and anion potential energy surfaces are calculated using the second-order Møller-Plesset perturbation theory with an empirical adjustment of the vertical attachment energy. The final-state vibrational distribution in the CF3(v2) fragment is dominated by the v2=2 state. We also find an increase in the total cross section as compared with the one-dimensional calculations. This is explained by an increase in the anion survival probability

Visualization of the Differential Transition State Stabilization within the Active Site Environment

Abstract: Increasing interest in the enzymatic reaction mechanisms and in the nature of catalytic effects in enzymes causes the need of appropriate visualization methods. A new interactive method to investigate catalytic effects using differential transition state stabilization approach (DTSS) [1, 2] is presented. The catalytic properties of the active site of cytidine deaminase (E.C. 3.5.4.5) is visualized in the form of differential electrostatic properties. The visualization was implemented using scripting interface of VMD [3]. Cumulative Atomic Multipole Moments (CAMM) [4,5,6] were utilized for efficient yet accurate evaluation of the electrostatic properties. The implementation is efficient enough for interactive presentation of catalytic effects in the active site of the enzyme due to transition state or substrate movement. This system of visualization of DTTS approach can be potentially used to validate hypotheses regarding the catalytic mechanism or to study binding properties of transition state analogues