The statistical model of atom–diatom insertion reactions is combined with coupled-channel capture theory and used to calculate differential cross sections for the C(1D), N(2D), O(1D) S(1D) H2. In case C(1D) S(1D), resulting are found be in excellent agreement recent quantum reactive scattering calculations Honvault Launay. They therefore also good molecular beam experiments S(1D)+H2 reaction, contrast results earlier based on a less rigorous theory. However, because exact mechanical N(2D)...

The study of insertion atom–diatom reactions is usually complicated by the existence deep potential wells between reactants and products. large number bound resonance states to be properly described makes exact quantum mechanical calculations extremely demanding in terms numerical effort. In this type collision, process proceeds via formation an intermediate complex finite lifetime. application statistical methods provides a valid alternative investigate dynamics reaction. work, studies...

The state-to-state differential cross sections for some atom + diatom reactions have been calculated using a new wave packet code, MAD-WAVE3, which is described in detail and uses either reactant or product Jacobi coordinates along the propagation. In order to show accuracy efficiency of coordinate transformation required when coordinates, as recently proposed [ J. Chem. Phys. 2006 , 125 054102 ], method first applied H D(2) reaction benchmark, exact time-independent calculations are also...

A recently derived transmission-free absorbing potential is applied to the study of atom–diatom chemical reactions. This only depends on a single parameter—the width region—and its reflection properties are guaranteed improve as this parameter increased. Converged results can therefore be obtained very easily, we illustrate with time-dependent wave packet calculations H+H2,F+H2, and H+O2

In this paper, we report a combined experimental and theoretical study on the dynamics of N(2D) + H2 insertion reaction at collision energy 15.9 kJ mol(-1). Product angular velocity distributions have been obtained in crossed beam experiments simulated by using results quantum mechanical (QM) scattering calculations accurate ab initio potential surface (PES) Pederson et al. (J. Chem. Phys. 1999, 110, 9091). Since QM indicate that there is significant coupling between product translational...

We report extensive, accurate fully quantum, time-independent calculations of cross sections at low collision energies, and rate coefficients temperatures for the H⁺ + H₂(v = 0, j) → j') reaction. Different transitions are considered, especially ortho-para conversion (j 1 j' 0) which is key importance in astrophysics. This process appears to be very efficient dominant temperature, with a coefficient 4.15 × 10⁻¹⁰ cm³ molecule⁻¹ s⁻¹ 10 K. The quantum mechanical results also compared...

Prestellar cores form from the contraction of cold gas and dust material in dark clouds before they collapse to protostars. Several concurrent theories exist describe this but are currently difficult distinguish. One major difference is timescale involved forming prestellar cores: some advocate nearly free-fall speed via, e.g., rapid turbulence decay, while others can accommodate much longer periods let accumulate ambipolar diffusion. To tell between these theories, measuring age could...

We review the solvation of atomic, molecular or cluster ions in HNDs. After briefly discussing properties snowballs bulk helium we consider experimental conditions for efficient synthesis charged, doped show that observed conventional mass spectrometers originate from fission highly charged The ionization threshold HNDs with alkalis reveals minimum size required full immersion. abundance distributions HeNX± frequently reveal local anomalies magic numbers. demonstrate is approximately...

Recently, it was shown how the primary steps of solvation a single Na$^+$ ion, instantly created at surface nanometer-sized droplet liquid helium, can be followed atomic level [Albrectsen et al. Nature $\textbf{623}$, 319 (2023)]. This involved measuring, with femtosecond time resolution, gradual attachment individual He atoms to ion as well energy dissipated from local region ion. In current work, we provide more comprehensive and detailed description experimental findings dynamics, present...

The H+ + H2 exchange reaction has been studied theoretically by means of a different variety methods as an exact time independent quantum mechanical, approximate wave packet, statistical quantum, and quasiclassical trajectory approaches. Total state-to-state probabilities in terms the collision energy for values total angular momentum obtained with these are compared. dynamics is extensively at E(coll)=0.44 eV. Integral differential cross sections opacity functions this have calculated. In...

A statistical model based on the quasiclassical trajectory method is presented in this work for atom-diatom insertion reactions. The basic difference between and corresponding quantum (SQM) lies fact that trajectories instead of wave functions are propagated entrance exit channels. Other than two formulations entirely similar. In particular, it shown conservation parity can be taken into account a natural precise way (SQCT) model. Additionally, SQCT complies with principle detailed balance...

The H++D2(v=0,j=0)→HD+D+ reaction has been theoretically investigated by means of a time independent exact quantum mechanical approach, wave packet calculation within an adiabatic centrifugal sudden approximation, statistical model, and quasiclassical trajectory calculation. Besides probabilities as function collision energy at different values the total angular momentum, J, special emphasis made two specific energies, 0.1 0.524eV. occurrence distinctive dynamical behavior these energies is...

Helium trimer bound states are calculated by means of a variational method described in terms atom pair coordinates and distributed Gaussian basis functions for zero total angular momentum. To show the feasibility this method, we also apply it to calculation first vibrational levels Ar3 Ne3 clusters. Special emphasis is made on study possible Efimov behavior excited state found He34 trimer. Geometrical configurations ground these rare gas trimers have been exhaustively studied owing proper...

Helium trimer bound states are calculated with a variational method described in terms of pair atom coordinates and distributed Gaussian functions by assuming zero total angular momentum. With the two-body interaction potential used, weakly state for dimer only two found. Although strictly speaking first excited is not an Efimov state, we show that this presents several characteristics behavior which extensively discussed present work. Special emphasis placed on main geometrical...

In this paper we report a combined experimental and theoretical study on the dynamics of insertion reaction C(D1)+D2 at 15.5kJmol−1 collision energy. Product angular velocity distributions have been obtained in crossed beam experiments quasiclassical trajectory (QCT) rigorous statistical calculations performed recent accurate ab initio potential energy surface Bussery-Honvault, Honvault, Launay experiment. The molecular-beam results simulated using calculations. Good agreement between...

The H(+)+D(2) and D(+)+H(2) reactive collisions are studied using a recently proposed adiabatic potential energy surface of spectroscopic accuracy. dynamics is an exact wave packet method on the at energies below curve crossing occurring approximately 1.5 eV above threshold. It found that reaction very well described by statistical quantum for zero total angular momentum (J) as compared with ones, while higher J some discrepancies found. For >0 different centrifugal sudden approximations...

A detailed comparison of statistical models based on the quasiclassical trajectory (SQCT) and quantum mechanical (SQM) methods is presented in this work for C((1)D)+H(2), S((1)D)+H(2), O((1)D)+H(2) N((2)D)+H(2) insertion reactions. Reaction probabilities, integral (ICS) differential (DCS) cross sections at different levels product's state resolution are shown discussed these The agreement most cases excellent indicates that effect tunneling through centrifugal barrier negligible. However, if...

The dynamics of the O + OH reaction on ground state potential energy surface (PES) is investigated by means quasiclassical trajectory method and two statistical methods: phase space theory quantum method. Preliminary calculations with an exact are also reported. show evidence for a bottleneck inhibiting intramolecular transfer between O-H O-O bonds. As result, probability intermediate complex dissociating back toward reactants high, thereby yielding significantly lower than expected...

A first principles study of the dynamics $^{6}\mathrm{Li}({}^{2}S)+^{6}\mathrm{Li}^{174}\mathrm{Yb}({}^{2}{\ensuremath{\Sigma}}^{+}){\ensuremath{\rightarrow}}^{6}{\mathrm{Li}}_{2}{(}^{1}{\ensuremath{\Sigma}}^{+}) + ^{174}\mathrm{Yb}({}^{1}S)$ reaction is presented at cold and ultracold temperatures. The computations involve determination analytic fitting a three-dimensional potential energy surface for ${\mathrm{Li}}_{2}\mathrm{Yb}$ system quantum calculations varying complexities, ranging...

Coronene-doped helium clusters have been studied by means of classical and quantum mechanical (QM) methods using a recently developed He–C24H12 global potential based on the use optimized atom-bond improved Lennard-Jones functions. Equilibrium energies geometries at local minima for systems with up to 69 He atoms were calculated an evolutive algorithm basin-hopping approach compared results from path integral Monte Carlo (PIMC) calculations 2 K. A detailed analysis performed smallest sizes...

The vibrational predissociation of the HeBr2 van der Waals complex is studied by means both accurate and approximate three dimensional quantum mechanical calculations. Simple atom–atom potentials have been tested for matching experimental measurements at low Br2 excitations. fragmentation dynamics when bromine subunit close to its B state dissociation limit then explored compared with experiments. For intermediate states v, good agreement most data (spectral shifts, lifetimes, average...

This article presents a quasiclassical trajectory (QCT) method to determine the reaction probability as function of total angular momentum J for any given value initial rotational j. The proposed is based on discrete sampling and orbital momenta each development equations that have clear counterpart in quantum-mechanical (QM) case. reliability illustrated by comparing QCT time-dependent wave-packet QM results H+D2(υ=0,j=4,10) reaction. small discrepancies between both sets calculations, when...

Integral cross sections and thermal rate constants have been calculated for the N((2)D)+H(2) reaction its isotopic variants N((2)D)+D(2) two-channel N((2)D)+HD by means of quasiclassical trajectory statistical quantum-mechanical model methods on latest ab initio potential-energy surface [T.-S. Ho et al., J. Chem. Phys. 119, 3063 (2003)]. The effect rotational excitation diatom dynamics these reactions has investigated interesting discrepancies between classical calculations found. Whereas a...

A complete formulation of a statistical quasiclassical trajectory (SQCT) model is presented in this work along with detailed comparison results obtained the quantum mechanical (SQM) for H++D2 and H++H2 reactions. The basic difference between SQCT SQM models lies fact that trajectories instead wave functions are propagated entrance exit channels. Other than two formulations entirely similar both comply principle balance conservation parity. Reaction probabilities, integral differential cross...