A5010781133- Spectroscopy and Quantum Chemical Studies
- Photochemistry and Electron Transfer Studies
- Advanced Chemical Physics Studies
- Protein Structure and Dynamics
- Molecular Junctions and Nanostructures
- Photoreceptor and optogenetics research
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Enzyme Structure and Function
- Synthesis and Properties of Aromatic Compounds
- Molecular spectroscopy and chirality
- Perovskite Materials and Applications
- Fullerene Chemistry and Applications
- Computational Drug Discovery Methods
- Quantum, superfluid, helium dynamics
- Spectroscopy and Laser Applications
- Photosynthetic Processes and Mechanisms
- RNA and protein synthesis mechanisms
- HER2/EGFR in Cancer Research
- Monoclonal and Polyclonal Antibodies Research
- Molecular Spectroscopy and Structure
- Advanced Photocatalysis Techniques
- Gold and Silver Nanoparticles Synthesis and Applications
- Laser-Matter Interactions and Applications
- Dendrimers and Hyperbranched Polymers
Consejo Nacional de Investigaciones Científicas y Técnicas
2016-2024
National University of Quilmes
2015-2024
University of Bern
2016-2020
Los Alamos National Laboratory
2009-2019
Center for Integrated Nanotechnologies
2009-2019
University of Bristol
2019
University of Leeds
2019
University of Florida
2009-2010
Universidad de Murcia
2010
Université Toulouse III - Paul Sabatier
1998-1999
To design functional photoactive materials for a variety of technological applications, researchers need to understand their electronic properties in detail and have ways control photoinduced pathways. When excited by photons light, organic conjugated (OCMs) show dynamics that are often characterized large nonadiabatic (NA) couplings between multiple states through breakdown the Born-Oppenheimer (BO) approximation. Following photoexcitation, various nonradiative intraband relaxation pathways...
After the outstanding breakthrough of AlphaFold in predicting protein 3D models, new questions appeared and remain unanswered. The ensemble nature proteins, for example, challenges structural prediction methods because models should represent a set conformers instead single structures. evolutionary features captured by effective deep learning techniques may unveil information to generate several diverse conformations from sequence. Here we address performance AlphaFold2 predictions obtained...
Radiationless transitions between electronic excited states in polyatomic molecules take place through unavoided crossings of the potential energy surfaces with substantial non-adiabatic coupling respective adiabatic states. While extent time these couplings are large enough, can be reasonably well simulated quantum using trajectory surface hopping-like methods. In addition, complex molecular systems may have multiple “trivial” noninteracting cases, described as sharp peaks strongly...
Nonadiabatic dynamics generally defines the entire evolution of electronic excitations in optically active molecular materials. It is commonly associated with a number fundamental and complex processes such as intraband relaxation, energy transfer, light harvesting influenced by spatial transformation photoexcitation into electrical via charge separation (e.g., injection at interfaces). To treat ultrafast excited-state exciton/charge transport we have developed nonadiabatic (NA-ESMD)...
Cycloparaphenylenes, the simplest structural unit of armchair carbon nanotubes, have unique optoelectronic properties counterintuitive in class conjugated organic materials. Our time-dependent density functional theory study and excited state dynamics simulations cycloparaphenylene chromophores provide a simple conceptually appealing physical picture explaining experimentally observed trends optical this family molecules. Fully delocalized degenerate second third excitonic states define...
Within the fewest switches surface hopping (FSSH) formulation, a swarm of independent trajectories is propagated and equations motion for quantum coefficients are evolved coherently along each nuclear trajectory. That is, phase factors, or amplitudes, retained. At region strong coupling, trajectory can branch into multiple wavepackets. Directly following hop, two wavepackets remain in nonadiabatic coupling continue exchanging population. After these have sufficiently separated space, they...
The Multiconfigurational Ehrenfest (MCE) method is a quantum dynamics technique which allows treatment of large number nuclear degrees freedom. This paper presents review MCE and its recent applications, providing summary the formalisms, including ab initio direct versions also giving results. Firstly, we describe version 2 (MCEv2) applicability to report new calculations show that approach converges exact result in model systems with tens Secondly, previous "on fly" Multiple Cloning...
Coherence, signifying concurrent electron-vibrational dynamics in complex natural and man-made systems, is currently a subject of intense study. Understanding this phenomenon important when designing carrier transport optoelectronic materials. Here, excited state simulations reveal ubiquitous pattern the evolution photoexcitations for broad range molecular systems. Symmetries wavefunctions define specific form non-adiabatic coupling that drives quantum transitions between states, leading to...
We present a versatile new code released for open community use, the nonadiabatic excited state molecular dynamics (NEXMD) package. This software aims to simulate using several semiempirical Hamiltonian models. To model such of system, NEXMD uses fewest-switches surface hopping algorithm, where probability transition from one another depends on strength derivative coupling. In addition, there are number algorithmic improvements as empirical decoherence corrections and tracking trivial...
Hemoglobin I (HbI) from the clam Lucina pectinata is an intriguing hemeprotein that binds and transports H(2)S to sulfide-oxidizing chemoautotrophic bacteria maintain a symbiotic relationship protect mollusk toxicity. Single point mutations at E7, B10, E11 were introduced into HbI heme pocket define reactivity of sulfide with hemeproteins. The functional structural properties mutant wild-type recombinant proteins first evaluated using well-known ferrous CO O(2) derivatives. effects these on...
Nonadiabatic molecular dynamics simulations, involving multiple Born-Oppenheimer potential energy surfaces, often require a large number of independent trajectories in order to achieve the desired convergence results, and simulation relies on different parameters that should be tested compared. In addition influencing speed simulation, chosen combined with frequently reduced can sometimes lead unanticipated changes accuracy simulated dynamics. We have previously developed nonadiabatic...
Abstract Nonradiative relaxation of high-energy excited states to the lowest state in chlorophylls marks first step process photosynthesis. We perform ultrafast transient absorption spectroscopy measurements, that reveal this internal conversion dynamics be slightly slower chlorophyll B than A . Modeling with non-adiabatic molecular simulations uncovers a critical role played by different side groups two molecules governing intramolecular redistribution wavefunction, leading, turn,...
The efficiency of materials developed for solar energy and technological applications depends on the interplay between molecular architecture light-induced electronic redistribution. spatial localization excitations is very sensitive to distortions. Vibrational nuclear motions can couple dynamics driving changes in localization. transfer among multiple chromophores arises from several distinct mechanisms that give rise experimentally measured signals. Atomistic simulations coupled...
The RepeatsDB database (URL: https://repeatsdb.org/) provides annotations and classification for protein tandem repeat structures from the Protein Data Bank (PDB). repeats are ubiquitous in all branches of tree life. accumulation solved new possibilities detection, but also increasing need annotation. Here we present 3.0, which addresses these challenges presents an extended scheme. major conceptual change compared to previous version is hierarchical combining top levels based solely on...
We present NEXMD version 2.0, the second release of (Nonadiabatic EXcited-state Molecular Dynamics) software package. Across a variety new features, v2.0 incorporates implementations two hybrid quantum-classical dynamics methods, namely, Ehrenfest (EHR) and Ab-Initio Multiple Cloning sampling technique for Multiconfigurational quantum (MCE-AIMC or simply AIMC), which are alternative options to previously implemented trajectory surface hopping (TSH) method. To illustrate these methodologies,...
The ultrafast dynamics of electronic and vibrational energy transfer between two- three-ring linear poly(phenylene ethynylene) units linked by meta-substitution is studied nonadiabatic molecular simulations. with quantum transitions(1, 2) method used including an "on the fly" calculation potential surfaces couplings. results show that during first 40 fs after a vertical photoexcitation to S2 state, coupling S1 states causes fast populations. A rapid decrease S1−S2 gap observed, reaching...
Non-adiabatic excited-state molecular dynamics is used to study the ultrafast intramolecular energy transfer between two-, three-, and four-ring linear polyphenylene ethynylene chromophore units linked through meta-substitutions. Twenty electronic energies, with their corresponding gradients nonadiabatic coupling vectors were included in simulations. The initial laser excitation creates an exciton delocalized different absorbing two-ring PPE units. Thereafter, we observe directional change...
Photoinduced dynamics of electronic and vibrational unidirectional energy transfer between <italic>meta</italic>-linked building blocks in a phenylene ethynylene dendrimer is simulated using multiconfigurational Ehrenfest time-dependent diabatic basis (MCE-TDDB) method.
Solar energy conversion starts with the harvest of light, and its efficacy depends on spatial transfer light to where it can be transduced into other forms energy. Harnessing solar power as a clean source requires continuous development new synthetic materials that photon transport without significant losses. With chemically-controlled branched architectures, dendrimers are ideally suited for these initial steps, since they consist arrays chromophores relative positioning orientations create...
Protein motions are a key feature to understand biological function. Recently, large-scale analysis of protein conformational diversity showed positively skewed distribution with peak at 0.5 Å C-alpha root-mean-square-deviation (RMSD). To this in terms structure-function relationships, we studied well curated and large dataset ~5,000 proteins experimentally determined diversity. We searched for global behaviour patterns studying how structure-based features change among the available...
The lack of an in-depth understanding the intrinsic oxygen vacancy (OV) defect properties in photoanode BiVO4 limits further improvement its photoelectrochemical water splitting performance. To address this issue, nonadiabatic molecular dynamics simulations are performed to study impact OV on charge carrier lifetimes BiVO4. show that a neutral gives rise local structural distortions due formation V–O–V bonds, forcing electrons trapped nearer two V atoms form deep polaron-like V4+ hole traps....
Direct atomistic simulation of nonadiabatic molecular dynamics is a challenging goal that allows important insights into fundamental physical phenomena. A variety frameworks, ranging from fully quantum treatment nuclei to semiclassical and mixed quantum–classical approaches, were developed. These algorithms are then coupled specific electronic structure techniques. Such diversity lack standardized implementation make it difficult compare the performance different methodologies when treating...