Abstract. Chemical reactivity modeling in large systems over extended time scales is computationally and theoretically challenging; ab initio methods are t

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For the first time, the structural response to pressure of a verdazyl radical crystal has been studied. Computational modelling revealed changes in electronic and magnetic properties as a result of a ...

Company Description: Waipapa Taumata Rau | The University of AucklanKo te whare Pūtaiao | The Faculty of Science at the University of Auckland is the largest and most highly ranked scie...

Roadmap on Advancements of the FHI-aims Software Package, Blum, Volker, Kokott, Sebastian, Rossi, Mariana, Scheffler, Matthias, Abbott, Joseph W. W., Mera Acosta, Carlos, Akkoush, Alaa, Ambrosetti, Alberto, Atalla, Viktor, Bagrets, Alexej, Behler, Joerg, Berger, Daniel, Bieniek, Björn, Björk, Jonas, Bohloul, Saeed, Box, Connor L., Boyer, Nicholas James, Brambila, Danilo Simoes, Bramley, Gabriel A., Bryenton, Kyle R., Camarasa-Gómez, María, Carbogno, Christian, Caruso, Fabio, Chutia, Sucismita, Ceriotti, Michele, Csányi, Gábor, Dawson, William, Delesma, Francisco A., della sala, fabio, Delley, Bernard, DiStasio, Robert, Dragoumi, Maria, Driessen, Sander, Dvorak, Marc, Erker, Simon, Evers, Ferdinand, Fabiano, Eduardo, Farrow, Matthew R., Fiebig, Florian, Filser, Jakob, Foppa, Lucas, Gallandi, Lukas, Garcia, Alberto, Gehrke, Ralf, Ghan, Simiam, Ghiringhelli, Luca, Glass, Mark, Goedecker, Stefan, Golze, Dorothea, Green, James A., Grisafi, Andrea, Grüneis, Andreas, Günzl, Johannes Jan, Gutzeit, Stefan, Hall, Samuel J., Hanke, Felix, Havu, Ville, He, Xingtao, Hekele, Joscha, Hellman, Olle, Herath, Uthpala, Hermann, Jan, Hernangómez-Pérez, Daniel, Hofmann, Oliver T, Hoja, Johannes, Hollweger, Simon, Hörmann, Lukas, Hourahine, Benjamin, How, Wei Bin, Huhn, William P., Hülsberg, Marcel, Panahian Jand, Sara, Jiang, Hongbing, Johnson, Erin, Jürgens, Werner, Kahk, Juhan Matthias, Kanai, Yosuke, Kang, Kisung, Karpov, Petr, Kempt, Roman, Khan, Danish, Kick, Matthias, Klein, Benedikt P., Kloppenburg, Jan, Knoll, Alexander, Knoop, Florian, Knuth, Franz, Köcher, Simone S., Kockläuner, Jannis, Körzdörfer, Thomas, Kowalski, Hagen-Henrik, Kratzer, Peter, Kus, Pavel, Laasner, Raul, Lang, Bruno, Lange, Björn, Langer, Marcel F, Larsen, Ask Hjorth, Lederer, Hermann

Chemical reactivity modelling in large systems over extended timescales is computationally and theoretically challenging; ab initio methods are too expensive, while classical force fields cannot handl...

The marvelous substrate recognition of enzyme hosts is attributed to induced-fit binding, in which the enzyme host maintains a delicate balance between preorganization and flexibility. For synthetic porous hosts such as MOFs, programmable control over the local and global flexibility modes is thus crucial for the optimization of host–guest interactions. Here we show that methylation adjacent to the pyrene-arene junction of the linker permits the synthesis of a derivative of NU-1000 in which aryl rotation is thermally inaccessible, but small-angle librations remain facile. Mechanochemically promoted Suzuki cross-coupling was able to overcome the twin challenges of poor solubility and steric congestion to access a linker that could not be prepared in solution. The incorporation of methyl groups in the linker controls the local dynamics of the MOF pore and permits a window that interconnects channels in the unsubstituted MOF to evolve into a separate micropore environment. In addition, we show how the different chemical shifts observed for nuclei that extend into distinct MOF pores permit experimental determination of rotational barriers via variable-temperature 13C solid-state NMR.

The mechanical properties of molecular crystals are fundamentally important in their industrial applications across pharmaceuticals, agrochemicals, energetic materials and other areas. Despite this, complete measurement or even computational prediction of elastic tensors for molecular crystals is anything but commonplace. The absence of rapid, reliable and broadly applicable methods in this endeavor frequently leads chemists to rely on intuitive ideas and examination of pairwise intermolecular interactions such as hydrogen- or halogen-bonds in order to rationalize the mechanical behavior of molecular crystals. Such perspectives are widespread in contemporary literature, but the extent to which these notions yield reliable and quantifiable insight is itself relatively unexplored. We propose a simple approximation, the Equilibrium Pairwise Model (EPM), compatible with any method to predict intermolecular interaction energies, that directly and efficiently yields an estimate of the complete elastic tensor. The protocol can be performed for any given molecular crystal structure, even those directly from experiment (i.e., without geometry optimization), and is guaranteed by construction to yield a positive-definite result─in contrast to conventional methods where computing valid elastic tensors for molecular crystals can prove challenging even for well-established and otherwise accurate model chemistries. We examine the accuracy of this protocol, along with other classical and contemporary methods, against experiment and periodic (plane-wave) density functional theory calculations to assess their reliability and accuracy. Through examination of the failures and successes, we aim to provide chemical insight into the kinds of materials where the model and, more broadly, thinking based on pairwise intermolecular interactions can reliably explain mechanical or other material properties and where they should be avoided.

Our mission is to transform lives and communities through education and research. Curtin employees form a unique and diverse community committed to innovative research and student learning. Find out a...

Our mission is to transform lives and communities through education and research. Curtin employees form a unique and diverse community committed to innovative research and student learning. Find out a...

Mechanical properties of molecular crystals are fundamentally important to their in- dustrial utility as pharmaceuticals or agrochemicals, energetic materials and more. Yet, complete measurements of e...

The structural response of a high-pressure phase of isobutyronitrile up to 6.12 GPa was studied by using high-pressure single-crystal X-ray diffraction, periodic density functional theory (DFT), and C...

PET-MAD is a fast and lightweight universal machine-learning potential, trained on a small but diverse dataset, that delivers near-quantum accuracy in atomistic simulations for both organic and inorga...

Our mission is to transform lives and communities through education and research. Curtin employees form a unique and diverse community committed to innovative research and student learning. Find out a...

Our mission is to transform lives and communities through education and research. Curtin employees form a unique and diverse community committed to innovative research and student learning. Find out a...

Scientists, research institutions, funders, libraries and publishers must all improve software practices.

Open Computational Chemistry - Quantum chemistry calculations in your browser

Nonadiabatic molecular dynamics simulations provide a theoretical understanding of various excited-state processes in photochemistry, offering access to band widths, radiative or nonradiative relaxation and corresponding lifetimes, excited-state energies, and charge transfer. The range of method developments within the framework of time-dependent density functional theory is exceedingly large for molecular quantum chemistry. Still, it shrinks significantly when aiming to treat periodic boundary conditions. To address this gap and complement existing software packages for solid-state nonadiabatic molecular dynamics, we present an interface between the CP2K electronic structure and the NEWTON-X surface hopping codes. The interface features the generation of initial conditions, as well as adiabatic and nonadiabatic molecular dynamics, based on phenomenological or numerical time-derivative couplings. Setups are validated on gas-phase pyrazine, with electronic absorption spectra and excited-state populations for transitions between the lowest singlet states being in agreement with established molecular quantum chemistry methods. Extending the system size to crystalline pyrazine, limitations of approximate couplings are discussed, and the efficiency and applicability of the interface are demonstrated by computing broad spectra over several eV and 100 fs trajectories, considering couplings between all 80th lowest excited states, at low computational cost with a mixed semiempirical density functional theory setup.

The Bethe–Salpeter equation (BSE) formalism, combined with the GW approximation for ionization energies and electron affinities, is emerging as an efficient and accurate method for predicting optical excitations in molecules. In this Letter, we present the first derivation and implementation of fully analytic nuclear gradients for the BSE@G0W0 method. Building on recent developments for G0W0 nuclear gradients, we derive analytic nuclear gradients for several BSE@G0W0 variants. We validate our implementation against numerical gradients and compare excited-state geometries and adiabatic excitation energies obtained from different BSE@G0W0 variants with those from state-of-the-art wave function methods.

We describe an efficient algorithm to compute the bridge length estimating the size of a complete isoset invariant, which classifies all periodic point sets under Euclidean motion.

Accurate and scalable machine-learned inter-atomic potentials (MLIPs) are essential for molecular simulations ranging from drug discovery to new material design. Current state-of-the-art models enforc...

Run LAMMPS molecular dynamics simulations in your browser

Machine learning is revolutionising materials modelling but requires high-quality training data. Here, the authors introduce autoplex, an open framework automating exploration and fitting of potential...

Simulating molecular adsorption on surfaces presents considerable challenges, as computational methods typically suffer from either insufficient accuracy or prohibitive computational costs. Now, with ...

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