Search results for "Rectangular potential barrier"

showing 2 items of 22 documents

Noise driven translocation of short polymers in crowded solutions

2008

In this work we study the noise induced effects on the dynamics of short polymers crossing a potential barrier, in the presence of a metastable state. An improved version of the Rouse model for a flexible polymer has been adopted to mimic the molecular dynamics by taking into account both the interactions between adjacent monomers and introducing a Lennard-Jones potential between all beads. A bending recoil torque has also been included in our model. The polymer dynamics is simulated in a two-dimensional domain by numerically solving the Langevin equations of motion with a Gaussian uncorrelated noise. We find a nonmonotonic behaviour of the mean first passage time and the most probable tran…

Statistics and ProbabilityPhysicschemistry.chemical_classificationQuantitative Biology::BiomoleculesStatistical Mechanics (cond-mat.stat-mech)Thermal fluctuationsEquations of motionFOS: Physical sciencesdynamics (theory) mechanical properties (DNA RNA membranes bio-polymers) (theory) Brownian MotionStatistical and Nonlinear PhysicsContext (language use)PolymerNoise (electronics)Condensed Matter::Soft Condensed MatterMolecular dynamicschemistryChemical physicsRectangular potential barrierStatistics Probability and UncertaintyFirst-hitting-time modelCondensed Matter - Statistical Mechanics
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Towards a converged barrier height for the entrance channel transition state of the N(2D)+CH4 reaction and its implication for the chemistry in Titan…

2011

Abstract The N( 2 D) + CH 4 reaction appears to be a key reaction for the chemistry of Titan’s atmosphere, opening the door to nitrile formation as recently observed by the Cassini–Huygens mission. Faced to the controversy concerning the existence or not of a potential barrier for this reaction, we have carried out accurate ab initio calculations by means of multi-state multi-reference configuration interaction (MS-MR-SDCI) method. These calculations have been partially corrected for the size-consistency errors (SCE) by Davidson, Pople or AQCC corrections. We suggest a barrier height of 3.86 ± 0.84 kJ/mol, including ZPE, for the entrance transition state, in good agreement with the experime…

chemistry.chemical_compoundsymbols.namesakeNitrilechemistryAb initio quantum chemistry methodssymbolsGeneral Physics and AstronomyRectangular potential barrierPhysical and Theoretical ChemistryAtomic physicsConfiguration interactionTitan (rocket family)Entrance channelChemical Physics Letters
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