Intramolecular vibrational redistribution in the non-radiative excited state decay of uracil in the gas phase: an ab initio molecular dynamics study

2015 ◽  
Vol 17 (17) ◽  
pp. 11615-11626 ◽  
Author(s):  
Philippe Carbonniere ◽  
Claude Pouchan ◽  
Roberto Improta
Keyword(s):  
Molecular Dynamics ◽  
Excited State ◽  
Ab Initio ◽  
Gas Phase ◽  
Ground State ◽  
Md Simulations ◽  
Ab Initio Molecular Dynamics ◽  
State Decay ◽  
State Recovery

MD simulations provide the first atomistic insights into the IVR processes of photoexcited uracil soon after ground state recovery.

Ab Initio Molecular Dynamics Simulations of an Excited State of X-(H2O)3(X = Cl, I) Complex

2005 ◽  
Vol 109 (42) ◽  
pp. 9419-9423 ◽  
Author(s):  
M. Kołaski ◽  
Han Myoung Lee ◽  
Chaeho Pak ◽  
M. Dupuis ◽  
Kwang S. Kim
Keyword(s):  
Molecular Dynamics ◽  
Excited State ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Ab Initio Molecular Dynamics ◽  
Dynamics Simulations

Geometry of OH⋯O interactions in the liquid state of linear alcohols from ab initio molecular dynamics simulations

2020 ◽  
Vol 22 (12) ◽  
pp. 6690-6697 ◽  
Author(s):  
Aman Jindal ◽  
Sukumaran Vasudevan
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonding ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Liquid State ◽  
Crystalline State ◽  
Md Simulations ◽  
Ab Initio Molecular Dynamics ◽  
Linear Alcohols ◽  
Dynamics Simulations

Hydrogen bonding OH···O geometries in the liquid state of linear alcohols, derived from ab initio MD simulations, show no change from methanol to pentanol, in contrast to that observed in their crystalline state.

scholarly journals Ab initio molecular dynamics study of the interaction of plutonium with oxygen in the gas phase

RSC Advances ◽  
2017 ◽  
Vol 7 (57) ◽  
pp. 36038-36047
Author(s):  
QingQing Wang ◽  
WenLang Luo ◽  
XiaoLi Wang ◽  
Tao Gao
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Gas Phase ◽  
Ab Initio Molecular Dynamics ◽  
Surface Corrosion

There are two kinds of plutonium surface corrosion, one of which is oxidation between plutonium and oxygen or oxygen compounds.

Energetics and diffusion of liquid water and hydrated ions through nanopores in graphene: ab initio molecular dynamics simulation

2017 ◽  
Vol 19 (31) ◽  
pp. 20551-20558 ◽  
Author(s):  
Raúl Guerrero-Avilés ◽  
Walter Orellana
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Functional Theory ◽  
Hydrated Ions ◽  
And Diffusion

The energetics and diffusion of water molecules and hydrated ions (Na+, Cl−) passing through nanopores in graphene are addressed by dispersion-corrected density functional theory calculations and ab initio molecular dynamics (MD) simulations.

scholarly journals Full Assignment of Ab-Initio Raman Spectra at Finite Temperatures Using Wannier Polarizabilities: Application to Cyclohexane Molecule in Gas Phase

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1212
Author(s):  
Pouya Partovi-Azar ◽  
Thomas Kühne
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Gas Phase ◽  
Raman Spectra ◽  
Predictive Power ◽  
Ab Initio Molecular Dynamics ◽  
Spatial Spread ◽  
Wannier Functions ◽  
Different Types ◽  
Cross Correlations

We demonstrate how to fully ascribe Raman peaks simulated using ab initio molecular dynamics to specific vibrations in the structure at finite temperatures by means of Wannier functions. Here, we adopt our newly introduced method for the simulation of the Raman spectra in which the total polarizability of the system is expressed as a sum over Wannier polarizabilities. The assignment is then based on the calculation of partial Raman activities arising from self- and/or cross-correlations between different types of Wannier functions in the system. Different types of Wannier functions can be distinguished based on their spatial spread. To demonstrate the predictive power of this approach, we applied it to the case of a cyclohexane molecule in the gas phase and were able to fully assign the simulated Raman peaks.

scholarly journals Proton Transfer from a Photoacid to Water: First Principles Simulations and Fast Fluorescence Spectroscopy

2021 ◽  
Author(s):  
Alice R. Walker ◽  
Boning Wu ◽  
Jan Meisner ◽  
Michael D. Fayer ◽  
Todd J. Martinez
Keyword(s):  
Molecular Dynamics ◽  
Excited State ◽  
Fluorescence Spectroscopy ◽  
Proton Transfer ◽  
Ab Initio ◽  
Time Constant ◽  
Emission Wavelength ◽  
Ab Initio Molecular Dynamics ◽  
Long Distance ◽  
Hydrogen Bonded

Proton transfer reactions are ubiquitous in chemistry, especially in aqueous solutions. We investigate photo-induced proton transfer between the photoacid 8-hydroxypyrene-1,3,6- trisulfonate (HPTS) and water using fast fluorescence spectroscopy and ab initio molecular dynamics simulations. Photo-excitation causes rapid proton release from the HPTS hydroxyl. Previous experiments on HPTS/water described the progress from photoexcitation to proton diffusion using kinetic equations with two time constants. The shortest time constant has been interpreted as protonated and photoexcited HPTS evolving into an “associated” state, where the proton is “shared” between the HPTS hydroxyl and an originally hydrogen bonded water. The longer time constant has been interpreted as indicating evolution to a “solvent separated” state where the shared proton undergoes long distance diffusion. In this work, we refine the previous experimental results using very pure HPTS. We then use excited state ab initio molecular dynamics to elucidate the detailed molecular mechanism of aqueous excited state proton transfer in HPTS. We find that the initial excitation results in rapid rearrangement of water, forming a strong hydrogen bonded network (a “water wire”) around HPTS. HPTS then deprotonates in ≤3 ps, resulting in a proton that migrates back and forth along the wire before localizing on a single water molecule. We find a near linear relationship between emission wavelength and proton-HPTS distance over the simulated time scale, suggesting that emission wavelength can be used as a ruler for proton distance. Our simulations reveal that the “associated” state corresponds to a water wire with a mobile proton and that the diffusion of the proton away from this water wire (to a generalized “solvent-separated” state) corresponds to the longest experimental time constant.

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