Dual-level dynamics

Dual-level dynamics " " refers to dynamics calculations that use two levels of electronic structure theory or two PEFs of different quality. In the VTST/MT context, such methods use a low-level method to calculate the MEP and gather some information along it followed by using a smaller... 

Dual-level direct dynamics of the hydroxyl radical reaction with ethane and haloethanes Toward a general reaction parameter method ... 

Our third generation direct dynamics scheme is called VTST with interpolated corrections (VTST-IC) or dual-level direct dynamics (DLDD) or triple-slash (///) dynamics. This approach involves three steps [49c] ... 

HL[HessL]///LL denotes a higher level of HL, except for the hessians which are calculated at level HessL, and a lower level of LL in a dual-level direct dynamics calculation. 

A. Femandez-Ramos, J. Rodriguez-Otero and M.A. Rfos, High level and dual level direct dynamics in the intramolecular proton transfer of hydrogenoxalate anion. Influence of tunneling and isotopic effect, J. Phys. Chem. A, 102 (1998) 2954. 

Both the dual-level descriptions and the NDDO-SRP approach have to be applied with care since they can lead to discontinuities and spurious minima in the PES function. Also, there are cases for which the reparametrization of a NDDO method is too difficult to provide more than just a qualitative insight into the reaction dynamics. Clearly, dual-level description and NDDO-SRP methods are only of limited value for a detailed investigation of reaction mechanism, energy transfer, and energy dissipation with the help of the RPH. 

Dual-Level Direct Dynamics Method for Reaction Rate Calculations with Inclusion of Multidimensional Tunneling Effects and Validation for the Reaction of H with trans-N2H2. 

Mapped Interpolation Scheme for Single-Point Energy Corrections in Reaction Rate Calculations and a Critical Evaluation of Dual-Level Reaction Path Dynamics Methods. 

Once we know the chemical nature of the allelopathic agents and their effects on plant growth dynamics, as well as on health and environment, we can apply genetic manipulation and biotechnology to develop toxin-resistant plants and to reduce the toxin levels frcm the donor plants. These approaches serve a dual purpose because they contribute to increased agricultural productivity and help to minimize the potential risks on health and environment. 

Another factor contributing to the asymmetry and breadth of absorption bands in crystal field spectra of transition metal ions is the dynamic Jahn-Teller effect, particularly for dissolved hexahydrated ions such as [Fe(H20)6]2+ and [Ti(H20)6]3+, which are not subjected to static distortions of a crystal structure. The degeneracies of the excited 5Eg and 2Eg crystal field states of Fe2+ and Ti3+, respectively, are resolved into two levels during the lifetime of the electronic transition. This is too short to induce static distortion of the ligand environment even when the cations occupy regular octahedral sites as in the periclase structure. A dual electronic transition to the resolved energy levels of the Eg excited states causes asymmetry and contributes to the broadened absorption bands in spectra of most Ti(m) and Fe(II) compounds and minerals (cf. figs 3.1,3.2 and 5.2). 

In Eq 1, sulfur compounds are combusted to sulfur monoxide (SO) and other products. In Eq 2, the second step of the mechanism, light energy (hv) in the blue region of the spectrum is emitted from the excited species resulting from the ozone reaction. The basic mechanism of the DP-SCD is the same as that described above, but two plasmas (flames) instead of one are provided to improve selectivity and the ability to measure lower sulfur levels without hydrocarbon interferences. A conceptual drawing of the flow dynamics used in the Dual Plasma burner is shown (Fig. 1). 

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