A5002652750- Phase Equilibria and Thermodynamics
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Chemical Thermodynamics and Molecular Structure
- Analytical Chemistry and Chromatography
- Zeolite Catalysis and Synthesis
- Metal-Organic Frameworks: Synthesis and Applications
- Thermodynamic properties of mixtures
- nanoparticles nucleation surface interactions
- Material Dynamics and Properties
- Machine Learning in Materials Science
- Crystallization and Solubility Studies
- Catalysis and Oxidation Reactions
- Mesoporous Materials and Catalysis
- Carbon Dioxide Capture Technologies
- Chromatography in Natural Products
- Advanced Thermodynamics and Statistical Mechanics
- Molecular Junctions and Nanostructures
- Surfactants and Colloidal Systems
- Theoretical and Computational Physics
- X-ray Diffraction in Crystallography
- Block Copolymer Self-Assembly
- Atmospheric chemistry and aerosols
- Catalytic Processes in Materials Science
- Quantum, superfluid, helium dynamics
University of Minnesota
2016-2025
University of Minnesota System
2018-2025
Twin Cities Orthopedics
2005-2024
TU Dortmund University
2023
Colorado School of Mines
2022
Northwestern University
2021
IMDEA Materials
2021
Minneapolis Institute of Arts
2018-2020
Center for Innovation
2017-2019
University of Delaware
2005-2017
A new set of united-atom Lennard-Jones interaction parameters for n-alkanes is proposed from fitting to critical temperatures and saturated liquid densities. Configurational-bias Monte Carlo simulations in the Gibbs ensemble were carried out determine vapor−liquid coexistence curves methane dodecane using three force fields: OPLS [Jorgensen, et al. J. Am. Chem. Soc. 1984, 106, 813], SKS [Siepmann, Nature 1993, 365, 330], TraPPE. Standard specific densities high-pressure equation-of-state...
Abstract New force fields for carbon dioxide and nitrogen are introduced that quantitatively reproduce the vapor–liquid equilibria (VLE) of neat systems their mixtures with alkanes. In addition to usual VLE calculations pure CO 2 N , binary propane were used in force‐field development achieve a good balance between dispersive electrostatic (quadrupole–quadrupole) interactions. The transferability was then assessed from n‐hexane, mixture /N ternary /propane. carried out using...
A new generalization of the configurational-bias Monte Carlo method is presented which avoids problems inherent in a Boltzmann rejection scheme for sequentially generating bond bending and torsional angles. The TraPPE-UA (transferable potentials phase equilibria united-atom) force field extended to include Lennard-Jones interaction parameters methine quaternary carbon groups by fitting critical temperatures saturated liquid densities branched alkanes. Configurational-bias simulations Gibbs...
The transferable potentials for phase equilibria-united atom (TraPPE-UA) force field hydrocarbons is extended to primary, secondary, and tertiary alcohols by introducing the following (pseudo-)atoms: common hydroxyl O H all alcohols, α-CH3, α-CH2, α-CH, α-C methanol, respectively. In TraPPE-UA field, nonbonded interactions of these sites are governed Lennard−Jones 12−6 Coulombic fixed partial charges. values charges were borrowed from optimized liquid simulations-united (OPLS−UA) [Jorgensen,...
Over 14 000 porous, three-dimensional metal–organic framework structures are compiled and analyzed as a part of an update to the Computation-Ready, Experimental Metal–Organic Framework Database (CoRE MOF Database). The updated database includes additional that were contributed by CoRE users, obtained from updates Cambridge Structural Web Science search, derived through semiautomated reconstruction disordered using topology-based crystal generator. In addition, value is added new analyses can...
The Transferable Potentials for Phase Equilibria-United Atom (TraPPE-UA) force field hydrocarbons is extended to alkenes and alkylbenzenes by introducing the following pseudo-atoms: CH2(sp2), CH(sp2), C(sp2), CH(aro), R−C(aro) link aliphatic side chains C(aro) of two benzene rings. In this united-atom field, nonbonded interactions hydrocarbon pseudo-atoms are solely governed Lennard-Jones 12−6 potentials, well depth size parameters new were determined fitting single-component...
For petrochemical applications knowledge of the critical properties n-alkanes is interest even at temperatures where these molecules are thermally unstable. Computer simulations can determine vapor–liquid coexistence curve a large number ranging from pentane (C5) through octatetracontane (C48). We have compared predicted phase diagrams various models with experimental data. Models which give nearly identical liquid alkanes standard conditions may that differ by more than 100 K. A new...
The extension of the transferable potentials for phase equilibria−united atom (TraPPE−UA) force field to ether, glycol, ketone, and aldehyde functionalities is presented. New parameters ether oxygen, carbonyl carbon (ketones), methine (aldehydes), a special intramolecular hydrogen-bond term were fitted vapor−liquid coexistence curves selected one-component systems. Coupled−decoupled configurational bias Monte Carlo simulations in Gibbs or grand canonical ensemble used compute neat systems...
We have used the classical molecular dynamics technique to simulate ordering of a water film adsorbed on an atomic model tip scanning tunneling microscope approaching planar metal surface. For this purpose, we developed for water–substrate interactions that solely depends coordinates particles and does not require definition geometrically smooth boundary surfaces or image planes. The includes both electrostatic induction atoms (determined by means extended Lagrangian technique) site-specific...
We present herein a comprehensive density functional theory study toward assessing the accuracy of two popular gradient-corrected exchange correlation functionals on structure and liquid water at near ambient conditions in isobaric−isothermal ensemble. Our results indicate that both PBE BLYP under predict over liquid. Adding dispersion correction due to Grimme(1, 2) improves predicted densities for significant manner. Moreover, addition yields an oxygen−oxygen radial distribution function...
The modular nature of metal–organic frameworks (MOFs) leads to a very large number possible structures. High-throughput computational screening has led rapid increase in property data that enabled several potential applications for MOFs, including gas storage, separations, catalysis, and other fields. Despite their rich chemistry, MOFs are typically named using an ad hoc approach, which can impede searchability the discovery broad insights. In this article, we develop two systematic MOF...
A linker extension strategy for generating metal-organic frameworks (MOFs) with superior moisture-capturing properties is presented. Applying this design approach involving experiment and computation results in MOF-LA2-1 {[Al(OH)(PZVDC)], where PZVDC2- (E)-5-(2-carboxylatovinyl)-1H-pyrazole-3-carboxylate}, which exhibits an approximately 50% water capacity increase compared to the state-of-the-art water-harvesting material MOF-303. The power of pore volume while retaining ability MOF harvest...
We construct a data set of metal-organic framework (MOF) linkers and employ fine-tuned GPT assistant to propose MOF linker designs by mutating modifying the existing structures. This strategy allows model learn intricate language chemistry in molecular representations, thereby achieving an enhanced accuracy generating structures compared with its base models. Aiming highlight significance design strategies advancing discovery water-harvesting MOFs, we conducted systematic variant expansion...
Machine learning and data mining coupled with molecular modeling have become powerful tools for materials discovery. Metal–organic frameworks (MOFs) are a rich area this due to their modular construction numerous applications. Here, we make from several previous large-scale studies in MOFs zeolites our groups (and new N2 Ar adsorption MOFs) easily accessible one place. The database includes over three million simulated points H2, CH4, CO2, Xe, Kr, Ar, 160 000 286 zeolites, textural...
Zeolitic imidazolate framework (ZIF-8) is a promising material for gas separation applications. It also serves as prototype numerous ZIFs, including amorphous ones, with broader range of possible applications, sensors, catalysis, and lithography. consists zinc coordinated 2-methylimidazolate (2mIm) has been synthesized methods ranging from liquid-phase to solvent-free synthesis, which aim control its crystal size shape, film thickness microstructure, incorporation into nanocomposites....
A series of first principles molecular dynamics and Monte Carlo simulations were carried out for liquid water to investigate the reproducibility different sampling approaches. These include Car−Parrinello using program cpmd with values fictitious electron mass in microcanonical canonical ensembles, Born−Oppenheimer programs cp2k ensemble, Metropolis ensemble. With exception one simulation 128 molecules, all other systems consisting 64 molecules. Although yield somewhat fortuitous agreement...
Motivated by shortcomings of the available united-atom models for alkanes, a new explicit-hydrogen model n-alkanes (TraPPE-EH, transferable potentials phase equilibria-explicit hydrogen) is developed from fitting to one-component fluid properties. In addition Lennard−Jones sites on carbon atoms, this utilizes centers carbon−hydrogen bonds. Configurational-bias Monte Carlo simulations in Gibbs and canonical ensembles were carried out calculate vapor−liquid equilibria methane n-dodecane,...
High-resolution 500 MHz solution-state 1H and 13C NMR spectra of various poly(lactides) indicate at least hexad stereosequence sensitivity. The were prepared in vials by melt polymerization combinations l-lactide, d-lactide, meso-lactide 180 °C for 3 h using tin(II) bis(2-ethylhexanoate) (tin(II) octoate) as the catalyst a 1:10 000 ratio. intensity distribution resonances indicates preference syndiotactic addition during process. Minimal evidence transesterification was observed these conditions.
The transferable potentials for phase equilibria (TraPPE) force fields are extended to amine, nitro, nitrile, and amide functionalities pyridine pyrimidine. In many cases, the same parameters a functional group used both united-atom explicit-hydrogen representations of alkyl tails. Following TraPPE philosophy, nonbonded interaction were fitted vapor−liquid coexistence curves selected one-component systems. Coupled−decoupled configurational-bias Monte Carlo simulations in Gibbs ensemble...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComputer Simulations of the Energetics and Siting n-Alkanes in ZeolitesBerend Smit J. Ilja SiepmannCite this: Phys. Chem. 1994, 98, 34, 8442–8452Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August 1994https://doi.org/10.1021/j100085a027RIGHTS & PERMISSIONSArticle Views589Altmetric-Citations199LEARN ABOUT THESE METRICSArticle Views are COUNTER-compliant sum full text article downloads since...
Recent simulation studies for four dipole-polarizable and two fluctuating-charge water force fields have demonstrated that none of the studied is capable yielding a satisfactory description vapor−liquid coexistence curve from room temperature to critical region. The performance these polarizable can be improved dramatically by introducing an additional coupling between Lennard−Jones interaction parameters pair oxygen sites their partial charges (electronic configuration). Two different types...
Climate models show that particles formed by nucleation can affect cloud cover and, therefore, the earth's radiation budget. Measurements worldwide rates in atmospheric boundary layer are positively correlated with concentrations of sulfuric acid vapor. However, current theories do not correctly predict either observed or their functional dependence on concentrations. This paper develops an alternative approach for modeling rates, based a sequence acid–base reactions. The model uses...