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Concept

Hückel method

Related publications (32)

Scanning Tunneling Microscopy for Molecules: Effects of Electron Propagation into Vacuum

Klaus Kern, Abhishek Grewal

Using scanning tunneling microscopy (STM), we experimentally and theoretically investigate isolated platinum phthalocyanine (PtPc) molecules adsorbed on an atomically thin NaCl(100) film vapor deposited on Au(111). We obtain good agreement between theory a ...

Amer Chemical Soc2024

Encoding quantum-chemical knowledge into machine-learning models of complex molecular properties

Ksenia Briling

Statistical (machine-learning, ML) models are more and more often used in computational chemistry as a substitute to more expensive ab initio and parametrizable methods. While the ML algorithms are capable of learning physical laws implicitly from data, ad ...

EPFL2024

koopmans: An Open-Source Package for Accurately and Efficiently Predicting Spectral Properties with Koopmans Functionals

Nicola Marzari, Nicola Colonna, Edward Baxter Linscott, Ngoc Linh Nguyen, Giovanni Borghi, Riccardo De Gennaro

Over the past decade we have developed Koopmans functionals, a computationally efficient approach for predicting spectral properties with an orbital-density-dependent functional framework. These functionals impose a generalized piecewise linearity conditio ...

Amer Chemical Soc2023

The fundamental relation between electrohelicity and molecular optical activity

Anne-Clémence Corminboeuf, Marc Hamilton Folkmann Garner

Electrohelicity arises in molecules such as allene and spiropentadiene when their symmetry is reduced and helical frontier molecular orbitals (MOs) appear. Such molecules are optically active and electrohelicity has been suggested as a possible design prin ...

ROYAL SOC CHEMISTRY2023

Five-Membered Rings Create Off-Zero Modes in Nanographene

Oleg Yazyev, Kristians Cernevics

The low-energy electronic structure of nanographenes can be tuned through zero-energy pi-electron states, typically referred to as zero-modes. Customizable electronic and magnetic structures have been engineered by coupling zero-modes through exchange and ...

Amer Chemical Soc2023

Advancing first principle-based molecular dynamics of biological systems with machine learning

François Louis Mouvet

Molecular dynamics (MD) simulations have emerged as a transformative approach to analyse molecular systems at the atomic level, offering valuable insights into complex biological processes. Many biological phenomena can only accurately be described by inco ...

EPFL2023

Equivariant representations for molecular Hamiltonians and N-center atomic-scale properties

Michele Ceriotti, Michael John Willatt, Jigyasa Nigam

Symmetry considerations are at the core of the major frameworks used to provide an effective mathematical representation of atomic configurations that is then used in machine-learning models to predict the properties associated with each structure. In most ...

AIP Publishing2022

Helical versus linear Jahn-Teller distortions in allene and spiropentadiene radical cations

Anne-Clémence Corminboeuf, Rubén Laplaza Solanas, Marc Hamilton Folkmann Garner

The allene radical cation can be stabilized both by Jahn-Teller distortion of the bond lengths and by torsion of the end-groups. However, only the latter happens and the allene radical cation relaxes into a twisted D-2 symmetry structure with equal double- ...

ROYAL SOC CHEMISTRY2022

Oxygen Evolution at the BiVO4-Water Interface: Mechanism of the Water Dehydrogenation Reaction

Alfredo Pasquarello, Julia Anna Wiktor, Sai Lyu

We study the water dehydrogenation reaction at the BiVO4(010)-water interface by combining nudged-elastic-band calculations and electronic structure calculations at the hybrid functional level. We investigate the pathway and the kinetic barrier for the adi ...

AMER CHEMICAL SOC2022

Koopmans Spectral Functionals in Periodic Boundary Conditions

Nicola Marzari, Nicola Colonna, Edward Baxter Linscott, Riccardo De Gennaro

Koopmans spectral functionals aim to describe simultaneously ground-state properties and charged excitations of atoms, molecules, nanostructures, and periodic crystals. This is achieved by augmenting standard density functionals with simple but physically ...

AMER CHEMICAL SOC2022

Mapping Orbital-Resolved Magnetism in Single Lanthanide Atoms

Harald Brune, Stefano Rusponi, Marina Pivetta, Fabio Donati, Aparajita Singha

Single lanthanide atoms and molecules are promising candidates for atomic data storage and quantum logic due to the long lifetime of their magnetic quantum states. Accessing and controlling these states through electrical transport requires precise knowled ...

AMER CHEMICAL SOC2021

The ONETEP linear-scaling density functional theory program

Edward Baxter Linscott

We present an overview of the onetep program for linear-scaling density functional theory (DFT) calculations with large basis set (plane-wave) accuracy on parallel computers. The DFT energy is computed from the density matrix, which is constructed from spa ...

AMER INST PHYSICS2020

Even-odd conductance effect in graphene nanoribbons induced by edge functionalization with aromatic molecules: basis for novel chemosensors

Oleg Yazyev, Michele Pizzochero, Kristians Cernevics

We theoretically investigate the electron transport in armchair and zigzag graphene nanoribbons (GNRs) chemically functionalized withp-polyphenyl and polyacene groups of increasing length. Our nearest-neighbor tight-binding calculations indicate that, depe ...

2020

Fine-Tuning by Triple Bond of Carbazole Derivative Dyes to Obtain High Efficiency for Dye-Sensitized Solar Cells with Copper Electrolyte

Ulf Anders Hagfeldt, Li Zhang

Three novel dyes consisting of a 5,8,15-tris(2-ethylhexyl)-8,15-dihydro-SH-benzo[1,2-b:3,4-b':6,5-b '']tricarbazole (BTC) electron-donating group and a 4,7-bis(4-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (BTBT) pi-bridge with an anchoring group of phen ...

AMER CHEMICAL SOC2020

Deterministic and Statistical Approaches to Quantum Chemistry

Alberto Fabrizio

The field of quantum chemistry has recently undergone a series of paradigm shifts, including a boom in machine learning applications that target the electronic structure problem. Along with these technological innovations, the community continues to identi ...

EPFL2020

Topology-Driven Single-Molecule Conductance of Carbon Nanothreads

Anne-Clémence Corminboeuf, Ganna Gryn'ova

Highly conductive single-molecule junctions typically involve pi-conjugated molecular bridges, whose frontier molecular orbital energy levels can be fine-tuned to best match the Fermi level of the leads. Fully saturated wires, e.g., alkanes, are typically ...

AMER CHEMICAL SOC2019

The influence of external electric fields on charge reorganization energy in organic semiconductors

Anne-Clémence Corminboeuf, Hongguang Liu

Charge reorganization energies (k) of inter-ring carbon-carbon (IRCC) bond connected conjugated polycyclics are shown to exhibit an electric-field-driven anisotropic character. An external electric field parallel to the IRCC linker(s) reduces k while the f ...

Royal Society of Chemistry2019

Functional Extrapolations to Tame Unbound Anions in Density-Functional Theory Calculations

Nicola Marzari, Oliviero Andreussi, Francesco Nattino

Standard flavors of density-functional theory (DFT) calculations are known to fail in describing anions, due to large self-interaction errors. The problem may be circumvented using localized basis sets of reduced size, leaving no variational flexibility fo ...

AMER CHEMICAL SOC2019

To bend or not to bend, the dilemma of multiple bonds

Michele Pizzochero

Beyond the second row of the periodic table, the nature of the multiple bonds between the elements of the main groups remains yet elusive, and "non-classical" bonding schemes are often invoked for their description. Here, focusing on group 14, we have perf ...

ROYAL SOC CHEMISTRY2019

Libraries of Extremely Localized Molecular Orbitals. 3. Construction and Preliminary Assessment of the New Databanks

Benjamin André René Meyer

The fast and reliable determination of wave functions and electron densities of macromolecules has been one of the goals of theoretical chemistry for a long time, and in this context, several linear scaling techniques have been successfully devised over th ...

AMER CHEMICAL SOC2018