Interacting Quantum Atoms—A Review

Molecules, Journal Year: 2020, Volume and Issue: 25(17), P. 4028 - 4028

Published: Sept. 3, 2020

The aim of this review is threefold. On the one hand, we intend it to serve as a gentle introduction Interacting Quantum Atoms (IQA) methodology for those unfamiliar with it. Second, expect act an up-to-date reference recent developments related IQA. Finally, want highlight non-exhaustive, yet representative set showcase examples about how use IQA shed light in different chemical problems. To accomplish this, start by providing brief context justify development real space alternative other existent energy partition schemes non-relativistic molecules. We then introduce self-contained algebraic derivation methodological ecosystem well overview these formulations vary level theory employed obtain molecular wavefunction upon which procedure relies. several applications examined research groups worldwide investigate wide variety

Language: Английский

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Non-covalent interactions from a Quantum Chemical Topology perspective

Journal of Molecular Modeling, Journal Year: 2022, Volume and Issue: 28(9)

Published: Aug. 25, 2022

Abstract About half a century after its little-known beginnings, the quantum topological approach called QTAIM has grown into widespread, but still not mainstream, methodology of interpretational chemistry. Although often confused in textbooks with yet another population analysis, be it perhaps an elegant somewhat esoteric one, been enriched about dozen other research areas sharing main mathematical language, such as Interacting Quantum Atoms (IQA) or Electron Localisation Function (ELF), to form overarching Chemical Topology (QCT). Instead reviewing latter’s role understanding non-covalent interactions, we propose number ideas emerging from full consequences space-filling nature atoms, and discuss how they (will) impact on interatomic including ones. The architecture force field FFLUX, which is based these ideas, outlined. A new method Relative Energy Gradient (REG) put forward, able, by computation, detect fragments given molecular assembly govern energetic behaviour this whole assembly. This can offer insight typical balance competing atomic energies both covalent case studies. brief discussion so-called bond critical points given, highlighting concerns their meaning, mainly arena interactions.

Language: Английский

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Atoms in molecules in real space: a fertile field for chemical bonding

Physical Chemistry Chemical Physics, Journal Year: 2023, Volume and Issue: 25(15), P. 10231 - 10262

Published: Jan. 1, 2023

In this Perspective we review some recent advances in the concept of atoms-in-molecules from a real space perspective.

Language: Английский

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A relative energy gradient (REG) study of the planar and perpendicular torsional energy barriers in biphenyl

Theoretical Chemistry Accounts, Journal Year: 2018, Volume and Issue: 138(1)

Published: Dec. 10, 2018

Biphenyl is a prototype molecule, the study of which important for proper understanding stereo-electronic effects. In gas phase it has an equilibrium central torsion angle ~ 45° and shows both planar (0°) perpendicular (90°) torsional energy barrier. The latter analysed first time. We use newly proposed REG method,

Language: Английский

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Does the Intra‐Atomic Deformation Energy of Interacting Quantum Atoms Represent Steric Energy?

ChemistryOpen, Journal Year: 2019, Volume and Issue: 8(5), P. 560 - 570

Published: Feb. 8, 2019

Abstract We show that the mutual, through‐space compression of atomic volume experienced by approaching topological atoms causes an exponential increase in intra‐atomic energy those atoms, regardless approach orientation. This insight was obtained using modern partitioning method called interacting quantum (IQA). behaviour is consistent for all except hydrogen, which can behave differently depending on its environment. Whilst experience charge transfer when they interact, hydrogen atom more vulnerable to these changes than larger atoms. The difference found be due hydrogen's lack a core electrons, which, heavier consistently provide repulsion compressed. As such, do not always steric hindrance. In accounting unusual and demonstrating character other we evidence IQA's as quantitative description energy.

Language: Английский

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Using the Relative Energy Gradient Method with Interacting Quantum Atoms to Determine the Reaction Mechanism and Catalytic Effects in the Peptide Hydrolysis in HIV‐1 Protease

Chemistry - A European Journal, Journal Year: 2018, Volume and Issue: 24(43), P. 11200 - 11210

Published: May 26, 2018

The reaction mechanism in an active site is of the utmost importance when trying to understand role that enzyme plays biological processes. In a recently published paper [Theor. Chem. Acc. 2017, 136, 86], we formalised Relative Energy Gradient (REG) method for automating Interacting Quantum Atoms (IQA) analysis. Here, REG utilised determine peptide hydrolysis aspartic HIV-1 Protease. Using along with IQA approach without employing any arbitrary parameters and remarkable ease (albeit at large computational cost: system contains 133 atoms, which means there are 17 689 individual terms be calculated). When work together it possible atomistic resolution from data directly derived quantum calculations, parameters. Moreover, determined by this novel gives concrete insight into how residues catalyse hydrolysis.

Language: Английский

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Directionality of Halogen Bonds: An Interacting Quantum Atoms (IQA) and Relative Energy Gradient (REG) Study

ChemPhysChem, Journal Year: 2019, Volume and Issue: 20(15), P. 1922 - 1930

Published: May 28, 2019

Abstract Interacting Quantum Atoms (IQA) and Fragments (IQF) analyses are used to study (X=Cl Br) model complexes in order determine the origin of halogen bond directionality. IQA allows for calculation intra‐ interatomic classical exchange‐correlation energies, which can be energetic nature changes that occur when deviating from preferred approach. The Relative Energy Gradient (REG) method is also applied rank energies reveal energy contributions best describe total behavior system. Indeed, all pairwise interactions atomic self‐energies angularly dependent; some terms favor linear structure tend toward nonlinear arrangements. For instance, C−X−N angle altered, halogen‐nitrogen interaction behaves like system while carbon‐nitrogen works against profile. Furthermore, REG values contribution small. Instead, secondary (e. g., fluorine‐nitrogen carbon‐hydrogen interactions) mainly responsible angular preference these bonds. Finally, IQF calculations followed by analysis importance self‐energy fragments.

Language: Английский

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Some Recent Advances in the Design and Use of Molecular Balances for the Experimental Quantification of Intramolecular Noncovalent Interactions of π Systems

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 25(45), P. 10516 - 10530

Published: May 14, 2019

Herein, various molecular balances used for comparing the strengths of intramolecular noncovalent interactions are reviewed. Our overview indicates that considerable quantitative insight into strength can be gained through careful design balances. Many exciting opportunities certainly exist further new to quantify and dissect relative as a function solvation importance many factors contribute overall recognition. However, even simple model molecules show multiplicity acting in combined fashion. It is therefore essential undertake detailed computational analysis identify all possible present selected balance prior experimental assessment particular interaction. also argued words "torsion" "molecular balance" seem have become inextricably linked and, consequence, top pan seesaw been mistakenly referred these terms.

Language: Английский

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Application of the FFLUX Force Field to Molecular Crystals: A Study of Formamide

Journal of Chemical Theory and Computation, Journal Year: 2023, Volume and Issue: 19(21), P. 7946 - 7959

Published: Oct. 17, 2023

In this work, we present the first application of quantum chemical topology force field FFLUX to solid state. utilizes Gaussian process regression machine learning models trained on data from interacting atom partitioning scheme predict atomic energies and flexible multipole moments that change with geometry. Here, ambient (α) high-pressure (β) polymorphs formamide are used as test systems optimized using FFLUX. Optimizing structures increasing multipolar ranks indicates lattice parameters α phase differ by less than 5% experimental structure when up quadrupole used. These differences found be in line dispersion-corrected density functional theory. Lattice dynamics calculations also possible FFLUX, yielding harmonic phonon spectra comparable DFT while enabling larger supercells considered is typically first-principles calculations. promising results indicate can accurately determine properties molecular solids difficult access DFT, including structural dynamics, free energies, at finite temperature.

Language: Английский

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A Re‐evaluation of Factors Controlling the Nature of Complementary Hydrogen‐Bonded Networks

ChemPhysChem, Journal Year: 2019, Volume and Issue: 20(4), P. 555 - 564

Published: Jan. 25, 2019

The energy profiles of hydrogen-bonded heterocyclic aromatics have been decomposed into atomistic contributions using the Interacting Quantum Atoms (IQA) method. resulting sequenced by Relative Energy Gradient (REG) approach to determine their influence upon shape these profiles. results show inadequacies in Jorgensen's secondary interaction hypothesis (SIH). A novel method finding a condensed analogy for between molecules is presented. findings this work further doubt validity SIH, and reinforce previous warnings against its misguided use.

Language: Английский

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