A5032175551- Spectroscopy and Quantum Chemical Studies
- Photochemistry and Electron Transfer Studies
- Molecular Junctions and Nanostructures
- Advanced Chemical Physics Studies
- Phase Equilibria and Thermodynamics
- Material Dynamics and Properties
- Polymer crystallization and properties
- Machine Learning in Materials Science
- Crystallization and Solubility Studies
- Polymer Foaming and Composites
- Photochromic and Fluorescence Chemistry
- X-ray Diffraction in Crystallography
- Surface Chemistry and Catalysis
- Photoreceptor and optogenetics research
- Rheology and Fluid Dynamics Studies
- nanoparticles nucleation surface interactions
- Force Microscopy Techniques and Applications
- Catalysis and Oxidation Reactions
- Polymer Nanocomposites and Properties
- DNA and Nucleic Acid Chemistry
- Light effects on plants
- Dielectric properties of ceramics
- Gyrotron and Vacuum Electronics Research
- Quantum optics and atomic interactions
- Block Copolymer Self-Assembly
Queens College, CUNY
2021-2024
Rutgers, The State University of New Jersey
2014-2023
Universidad Politécnica de Madrid
2018-2022
Rutgers Sexual and Reproductive Health and Rights
2016-2018
Newark Hospital
2016-2018
District University of Bogotá
2013
Near infrared (NIR, 700–1000 nm) and short-wave (SWIR, 1000–2000 dye molecules exhibit significant nonradiative decay rates from the first singlet excited state to ground state. While these trends can be empirically explained by a simple energy gap law, detailed mechanisms of nearly universal behavior have remained unsettled for many cases. Theoretical experimental results two representative NIR/SWIR reported here clarify key mechanism observed law behavior. It is shown that derivative...
We have carried out a thorough benchmark of the frozen density-embedding (FDE) method for calculating hole transfer couplings. considered 10 exchange-correlation functionals, 3 nonadditive kinetic energy and basis sets. Overall, we conclude that with 7% mean relative unsigned error, PBE PW91 functionals coupled PW91k functional TZP set constitute most stable accurate levels theory coupling calculations. The FDE-ET is found to be an excellent tool computing diabatic couplings reactions.
Exploiting the machinery of Constrained Density Functional Theory (CDFT), we propose a variational method for calculating low-lying excited states molecular systems. We dub this eXcited CDFT (XCDFT). Excited are obtained by self-consistently constraining user-defined population electrons, Nc, in virtual space reference set occupied orbitals. By imposing to be Nc = 1.0, computed first state 15 molecules from test set. Our results show that XCDFT achieves an accuracy predicted excitation...
We present results from extensive Monte Carlo simulations on the crystallization of athermal polymers under full confinement. Polymers are represented as freely jointed chains tangent hard spheres uniform size. Confinement is applied through presence flat, parallel, and impenetrable walls in all dimensions. analyze summation two contributions: one that occurs bulk volume system (bulk crystallization), wall surfaces (surface crystallization). Depending fraction initially amorphous...
Constrained Subsystem Density Fucntional Theory (CSDFT) allows to compute diabatic states for charge transfer reactions using the machinery of constrained DFT method, and at same time is able embed such in a molecular environment<italic>via</italic>a subsystem scheme.
Microcrystal electron diffraction, grazing incidence wide-angle scattering, and UV-Vis spectroscopy were used to determine the unit cell structure relative composition of dimethylated diketopyrrolopyrrole (MeDPP) H- J-polymorphs within thin films subjected vapor solvent annealing (VSA) for different times. Electronic excited state deactivation pathways polymorphs examined by transient absorption spectroscopy, conductive probe atomic force microscopy, molecular modeling. We find VSA initially...
We investigate, through Monte Carlo simulations, the heterogeneous crystallization of linear chains tangent hard spheres under confinement in one dimension. Confinement is realized flat, impenetrable, and parallel walls. A wide range systems studied with respect to their average chain lengths (N = 12 100) packing densities (φ 0.50 0.61). The local structure quantified Characteristic Crystallographic Element (CCE) norm descriptor. Here, we split phenomenon into bulk crystallization, far from...
In the past two decades, many research groups worldwide have tried to understand and categorize simple regimes in charge transfer of such biological systems as DNA. Theoretically speaking, lack exact theories for electron–nuclear dynamics on one side poor quality parameters needed by model Hamiltonians nonadiabatic alike (such couplings site energies) other are main difficulties an appropriate description phenomena. this work, we present application a previously benchmarked linear-scaling...
Green technologies rely on green solvents and fluids. Among them, supercritical CO2 already finds many important applications. The molecular-level understanding of the dynamics structure this fluid is a prerequisite for rational design future technologies. Unfortunately, commonly employed Kohn-Sham density functional theory (DFT) too computationally demanding to produce meaningfully converged within reasonable time with computational effort. Thanks subsystem DFT, we analyze finite-size...
In the present work, we revise and extend Characteristic Crystallographic Element (CCE) norm, an algorithm used to simultaneously detect radial orientational similarity of computer-generated structures with respect specific reference crystals local symmetries. Based on identification point group symmetry elements, CCE descriptor is able gauge structure high precision finely distinguish between competing morphologies. As test cases use monomeric polymer systems spherical particles interacting...
We present Simu-D, a software suite for the simulation and successive identification of local structures atomistic systems, based on polymers, under extreme conditions, in bulk, surfaces, at interfaces. The protocol is built around various types Monte Carlo algorithms, which include localized, chain-connectivity-altering, identity-exchange, cluster-based moves. approach focuses alleviating one main disadvantages general applicability wide range conditions. Present applications polymer-based...
In the present work we revise and extend Characteristic Crystallographic Element (CCE) norm, an algorithm used to simultaneously detect radial orientational similarity of computer-generated structures with respect specific reference crystals local symmetries. Based on identification point group symmetry elements, CCE descriptor is able gauge structure high precision finely distinguish between competing morphologies. As test cases use monomeric polymer systems spherical particles interacting...
The low energy excited states of the conformational isomers solvated azobenzene are calculated with several DFT methods accounting for solute-solvent interaction implicitly polarizable continuum model or explicitly subsystem DFT. For latter, embedding potentials 21 sampled snapshots solvent molecules. First, we find that has little effect on predicted cis-trans S1 excitation gap. Second, azobenzene's cis and trans energies accurate as long a screened range-separated hybrid...
Understanding and predicting the properties of molecular liquids from corresponding individual molecules is notoriously difficult because there cooperative behavior among in liquid. This particularly relevant for water, where even most fundamental properties, such as dipole moment, are radically different liquid compared to gas phase. In this work, we focus on ionization potential (IP) water by dissecting its contributions making up achieved using periodic subsystem DFT, a state-of-the-art...
Monte Carlo (MC) simulations, built around chain-connectivity-altering moves and a wall-displacement algorithm, allow us to simulate freely-jointed chains of tangent hard spheres uniform size under extreme confinement. The latter is realized through the presence two impenetrable, flat, parallel plates. Extreme conditions correspond case where distance between plates approaches monomer size. An analysis local structure, based on characteristic crystallographic element (CCE) norm, detects...
A surfactant-free sonication-induced route is developed to facilely prepare colloidal nanocrystals of Li-excess layered Li1.2Mn0.54Ni0.13Co0.13O2 (marked as LMNCO) material. The sonication process plays a critical role in forming LMNCO ethanol (ethanol molecules marked EtOHs) and inducing the interaction between solvent molecules. formation mechanism LMNCO–EtOH supramolecules dispersion system proposed examined by theoretical simulation light scattering technique. It suggested that as-formed...
Excited Costrained Density Functional Theory (XCDFT) [Ramos and Pavanello, J. Chem. Phys. 148, 144103 (2018)] is a variational excited state method that extends ground DFT to the computation of low-lying states. It borrows much machinery Constrained (CDFT) with crucial difference: constraint imposes population one electron in Hilbert space spanned by virtuals reference state. In this work, we present theory implementation for evaluating nonadiabatic coupling vectors (NACVs) between first...
Charge transfer is investigated in a planar dyad adsorbed on an insulting layer <italic>via</italic> local electronic excitations.
The computation of excited electronic states with commonly employed (approximate) methods is challenging, typically yielding lower quality than the corresponding ground state for a higher computational cost. In this work, we present mean-field method that extends previously proposed constrained-density-functional theory (XCDFT) from single Slater determinants to ensemble one-body reduced density matrices computing low-lying states. still retains an associated complexity comparable semilocal...