Nonadiabatic nuclear dynamics of the ammonia cation studied by surface hopping classical trajectory calculations.

  title={Nonadiabatic nuclear dynamics of the ammonia cation studied by surface hopping classical trajectory calculations.},
  author={Andrey K. Belyaev and Wolfgang Domcke and Caroline Lasser and Giulio Trigila},
  journal={The Journal of chemical physics},
  volume={142 10},
The Landau-Zener (LZ) type classical-trajectory surface-hopping algorithm is applied to the nonadiabatic nuclear dynamics of the ammonia cation after photoionization of the ground-state neutral molecule to the excited states of the cation. The algorithm employs a recently proposed formula for nonadiabatic LZ transition probabilities derived from the adiabatic potential energy surfaces. The evolution of the populations of the ground state and the two lowest excited adiabatic states is calculated… 

Figures and Tables from this paper

Assessing the performance of trajectory surface hopping methods: Ultrafast internal conversion in pyrazine.

Nonadiabatic dynamics simulations with the widely used Tully's fewest switches surface hopping (FSSH) algorithm and a Landau-Zener-type TSH (LZSH) algorithm have been performed for the internal conversion dynamics of pyrazine, finding that the electronic population dynamics obtained with the LZSH method is in excellent agreement with that obtained by the FSSH method using a local diabatization algorithm.

Nonadiabatic dynamics of floppy hydrogen bonded complexes: the case of the ionized ammonia dimer.

The simulations showed that the ionized ammonia dimer is highly unstable and its decay rate is primarily driven by the position of the electron hole, which indicates that the minimum energy and vibrationally averaged structures are rather different.

Electron detachment of hydrogen anion in collisions with hydrogen molecule studied by surface hopping classical trajectory calculations.

The on-the-fly surface hopping classical trajectory algorithm is employed to study the electron detachment process in low-energy H- + H2 collisions and it is shown that the direct mechanism prevails at low collision energies, while the indirect mechanism makes a substantial contribution at relatively high collision energies.

Pragmatic Approach to Photodynamics: Mixed Landau-Zener Surface Hopping with Inter-system Crossing.

This work explores the performance of the recently reformulated Landau-Zener surface hopping (LZSH) approach and extends it for the simultaneous treatment of internal conversion and intersystem crossing events and argues that the accuracy of photodynamical simulations is in practice dominated by the electronic structure theory and it is legitimate to use the simplest and the most efficient technique.

Accuracy of trajectory surface-hopping methods: Test for a two-dimensional model of the photodissociation of phenol.

The accuracy of two TSH algorithms, Tully's fewest switching algorithm and an algorithm based on the Landau-Zener formula, has been critically evaluated in comparison with exact nonadiabatic quantum dynamics calculations for a model of the photoinduced hydrogen-atom dissociation reaction in phenol.

A fast and robust trajectory surface hopping method: Application to the intermolecular photodissociation of a carbon dioxide dimer cation (CO2)2.

The recently developed trajectory surface hopping method uses numerical time derivatives of adiabatic potential gradients to estimate the nonadiabatic transition probability and the hopping direction and gave similar results to the fewest switches algorithm at lower computational expense.

Ab Initio Nonadiabatic Surface-Hopping Trajectory Simulations of Photocatalytic Water Oxidation and Hydrogen Evolution with the Heptazine Chromophore.

Detailed insight into the interplay of various nonadiabatic electronic transitions, electron transfer, proton transfer, and vibrational energy relaxation is obtained and delineate for the first time a quantitatively supported scenario of water oxidation and hydrogen evolution with a molecular carbon nitride photocatalyst.

On the importance of initial conditions for excited-state dynamics.

A new technique is introduced, CW-sampling, to treat photodynamical processes initiated by absorption at the tail of the UV absorption spectrum, based on the ideas of importance sampling, combined with the quantum thermostat approachbased on the Generalized Langevin Equation that allows for efficient sampling of both position and momentum space.

Asymptotic analysis of diabatic surface hopping algorithm in the adiabatic and non-adiabatic limits

A BSTRACT . Surface hoppingalgorithms,as an importantclass ofquantumdynamics simulation algorithms for non-adiabatic dynamics, are typically performed in the adiabatic representation,which can break

Electronically nonadiabatic wave packet propagation using frozen Gaussian scattering.

An approach, which allows to employ the adiabatic wave packet propagation technique and semiclassical theory to treat the nonadiabatic processes by using trajectory hopping, and it is shown that photoabsorption spectrum is successfully reproduced by using a few hundreds of trajectories.

Photoionization-induced dynamics of ammonia: ab initio potential energy surfaces and time-dependent wave packet calculations for the ammonia cation.

An analytical anharmonic six-dimensional three-sheeted potential energy surface for the ground and first excited states of the ammonia cation has been developed which is tailored to model the

Landau-Zener type surface hopping algorithms.

A class of surface hopping algorithms is studied comparing two recent Landau-Zener (LZ) formulas for the probability of nonadiabatic transitions, which confirm the affinity of both the LZ probabilities, as well as the good approximation of the reference solution computed by solving the Schrödinger equation via a grid based pseudo-spectral method.

Surface-hopping modeling of photoinduced relaxation dynamics on coupled potential-energy surfaces

A mixed quantum-classical description of nonadiabatic photoreactions such as internal conversion and electron transfer is outlined. In particular the validity and limitations of Tully’s

Trajectory Surface Hopping Approach to Nonadiabatic Molecular Collisions: The Reaction of H+ with D2

An extension of the classical trajectory approach is proposed that may be useful in treating many types of nonadiabatic molecular collisions. Nuclei are assumed to move classically on a single

Trajectory Surface Hopping Study of the Li + Li2(X1Σg+) Dissociation Reaction

Trajectory surface hopping calculations are reported for the Li + Li2(X1Σg+) dissociation reaction over the range of translational energies 13 ≤ Etr/kcal mol-1 ≤ 80. Both potential energy surfaces

Molecular dynamics with electronic transitions

A method is proposed for carrying out molecular dynamics simulations of processes that involve electronic transitions. The time dependent electronic Schrodinger equation is solved self‐consistently

Semiclassical Theory of Electronic Transitions in Low Energy Atomic and Molecular Collisions Involving Several Nuclear Degrees of Freedom

A semiclassical theory is developed for describing electronic transitions in low energy atomic and molecular collisions, such as A+BC, that involve quantized nuclear degrees of freedom (i.e.,