Molecular dynamics simulations of energy dissipation and non-thermal diffusion on amorphous solid water

2018 ◽  
Vol 20 (8) ◽  
pp. 5569-5577 ◽  
Author(s):  
A. Fredon ◽  
H. M. Cuppen

Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst.

2020 ◽  
Vol 22 (14) ◽  
pp. 7552-7563 ◽  
Author(s):  
Germán Molpeceres ◽  
Johannes Kästner

We present a method based on ab initio molecular dynamics to study the adsorption dynamics of adsorbates on interstellar surfaces.


2016 ◽  
Vol 52 (16) ◽  
pp. 3403-3405 ◽  
Author(s):  
Said Jalife ◽  
Sukanta Mondal ◽  
Jose Luis Cabellos ◽  
Gerardo Martinez-Guajardo ◽  
Maria A. Fernandez-Herrera ◽  
...  

Born–Oppenheimer molecular dynamics simulations and high-level ab initio computations predict that the cage-opening rearrangement of the cubyl cation to the 7H+-pentalenyl cation is feasible in the gas phase.


2008 ◽  
Vol 77 (8) ◽  
Author(s):  
Sébastien Rives ◽  
Alain Catherinot ◽  
Frédéric Dumas-Bouchiat ◽  
Corinne Champeaux ◽  
Arnaud Videcoq ◽  
...  

2017 ◽  
Vol 12 ◽  
pp. 23-37 ◽  
Author(s):  
Riccardo Ferrando

The diffusion of atoms in nanoparticles can be studied computationally by Molecular Dynamics simulations, a simulation method which allow to follow the actual trajectories of the diffusing atoms. Here we focus on the simulation of diffusion in metallic nanoparticles, first considering the case of single impurity atoms in matrix clusters, and then on the simulation of the growth in gas phase. We show that diffusion of atoms in nanoparticles can take place by a variety of different mechanisms, which very often involve collective displacements. These collective displacements are facilitated in the vicinity of the cluster surface, which, in small nanoparticles, includes a large portion of the nanoparticle itself.


2014 ◽  
Vol 126 (14) ◽  
pp. 3737-3740 ◽  
Author(s):  
Sander Jaeqx ◽  
Jos Oomens ◽  
Alvaro Cimas ◽  
Marie-Pierre Gaigeot ◽  
Anouk M. Rijs

2016 ◽  
Vol 195 ◽  
pp. 237-251 ◽  
Author(s):  
Rafał Szabla ◽  
Robert W. Góra ◽  
Mikołaj Janicki ◽  
Jiří Šponer

Photochemically created πσ* states were classified among the most prominent factors determining the ultrafast radiationless deactivation and photostability of many biomolecular building blocks. In the past two decades, the gas phase photochemistry of πσ* excitations was extensively investigated and was attributed to N–H and O–H bond fission processes. However, complete understanding of the complex photorelaxation pathways of πσ* states in the aqueous environment was very challenging, owing to the direct participation of solvent molecules in the excited-state deactivation. Here, we present non-adiabatic molecular dynamics simulations and potential energy surface calculations of the photoexcited imidazole–(H2O)5 cluster using the algebraic diagrammatic construction method to the second-order [ADC(2)]. We show that electron driven proton transfer (EDPT) along a wire of at least two water molecules may lead to the formation of a πσ*/S0 state crossing, similarly to what we suggested for 2-aminooxazole. We expand on our previous findings by direct comparison of the imidazole–(H2O)5 cluster to non-adiabatic molecular dynamics simulations of imidazole in the gas phase, which reveal that the presence of water molecules extends the overall excited-state lifetime of the chromophore. To embed the results in a biological context, we provide calculations of potential energy surface cuts for the analogous photorelaxation mechanism present in adenine, which contains an imidazole ring in its structure.


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