@misc{33688, author = {{Balos, Vasileios and Kaliannan, Naveen Kumar and Elgabarty, Hossam and Wolf, Martin and Kühne, Thomas and Sajadi, Mohsen}}, publisher = {{LibreCat University}}, title = {{{Time resolved THz-Raman spectroscopy reveals that cations and anions distinctly modify intermolecular interactions of water}}}, doi = {{10.5281/ZENODO.6514905}}, year = {{2022}}, } @article{33691, abstract = {{Near ambient pressure XPS in nitrogen atmosphere was utilized to investigate gas-solid interactions within porous SiO2 films ranging from 30 to 75 nm thickness. The films were differentiated in terms of porosity and roughness. The XPS N1s core levels of the N2 gas in presence of the SiO2 samples showed variations in width, binding energy and line shape. The width correlated with the surface charge induced in the dielectric films upon X-ray irradiation. The observed different binding energies observed for the N1s peak can only partly be associated with intrinsic work function differences between the samples, opening the possibility that the effect of physisorption at room temperature could be detected by a shift in the measured binding energy. However, the signals also show an increasing asymmetry with rising surface charge. This might be associated with the formation of vertical electrical gradients within the dielectric porous thin films, which complicates the assignment of binding energy positions to specific surface-related effects. With the support of Monte Carlo and first principles density functional theory calculations, the observed shifts were discussed in terms of the possible formation of transitory dipoles upon N2 physisorption within the porous SiO2 films.}}, author = {{de los Arcos, Teresa and Weinberger, Christian and Zysk, Frederik and Raj Damerla, Varun and Kollmann, Sabrina and Vieth, Pascal and Tiemann, Michael and Kühne, Thomas and Grundmeier, Guido}}, issn = {{0169-4332}}, journal = {{Applied Surface Science}}, keywords = {{Surfaces, Coatings and Films, Condensed Matter Physics, Surfaces and Interfaces, General Physics and Astronomy, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Challenges in the interpretation of gas core levels for the determination of gas-solid interactions within dielectric porous films by ambient pressure XPS}}}, doi = {{10.1016/j.apsusc.2022.154525}}, volume = {{604}}, year = {{2022}}, } @article{33685, abstract = {{In the spatial confinement of cylindrical mesopores with diameters of a few nanometers, water molecules experience restrictions in hydrogen bonding. This leads to a different behavior regarding the molecular orientational freedom (‘structure of water') compared to the bulk liquid state. In addition to the pore size, the behavior is also strongly affected by the strength of the pore wall-to-water interactions, that is, the pore wall polarity. In this work, this is studied both experimentally and theoretically. The surface polarity of mesoporous silica (SiO2) is modified by functionalization with trimethylsilyl moieties, resulting in a change from a hydrophilic (pristine) to a hydrophobic pore wall. The mesopore surface is characterized by N2 and H2O sorption experiments. Those results are combined with IR spectroscopy to investigate pore wall-to-water interactions leading to different structures of water in the mesopore. Furthermore, the water's structure is studied theoretically to gain deeper insight into the interfacial interactions. For this purpose, the structure of water is analyzed by pairing densities, coordination, and angular distributions with a novel adaptation of surface-specific sum-frequency generation calculation for pore environments.}}, author = {{Weinberger, Christian and Zysk, Frederik and Hartmann, Marc and Kaliannan, Naveen and Keil, Waldemar and Kühne, Thomas and Tiemann, Michael}}, issn = {{2196-7350}}, journal = {{Advanced Materials Interfaces}}, keywords = {{Mechanical Engineering, Mechanics of Materials}}, number = {{20}}, publisher = {{Wiley}}, title = {{{The Structure of Water in Silica Mesopores – Influence of the Pore Wall Polarity}}}, doi = {{10.1002/admi.202200245}}, volume = {{9}}, year = {{2022}}, } @unpublished{33493, abstract = {{Electronic structure calculations have been instrumental in providing many important insights into a range of physical and chemical properties of various molecular and solid-state systems. Their importance to various fields, including materials science, chemical sciences, computational chemistry and device physics, is underscored by the large fraction of available public supercomputing resources devoted to these calculations. As we enter the exascale era, exciting new opportunities to increase simulation numbers, sizes, and accuracies present themselves. In order to realize these promises, the community of electronic structure software developers will however first have to tackle a number of challenges pertaining to the efficient use of new architectures that will rely heavily on massive parallelism and hardware accelerators. This roadmap provides a broad overview of the state-of-the-art in electronic structure calculations and of the various new directions being pursued by the community. It covers 14 electronic structure codes, presenting their current status, their development priorities over the next five years, and their plans towards tackling the challenges and leveraging the opportunities presented by the advent of exascale computing.}}, author = {{Gavini, Vikram and Baroni, Stefano and Blum, Volker and Bowler, David R. and Buccheri, Alexander and Chelikowsky, James R. and Das, Sambit and Dawson, William and Delugas, Pietro and Dogan, Mehmet and Draxl, Claudia and Galli, Giulia and Genovese, Luigi and Giannozzi, Paolo and Giantomassi, Matteo and Gonze, Xavier and Govoni, Marco and Gulans, Andris and Gygi, François and Herbert, John M. and Kokott, Sebastian and Kühne, Thomas and Liou, Kai-Hsin and Miyazaki, Tsuyoshi and Motamarri, Phani and Nakata, Ayako and Pask, John E. and Plessl, Christian and Ratcliff, Laura E. and Richard, Ryan M. and Rossi, Mariana and Schade, Robert and Scheffler, Matthias and Schütt, Ole and Suryanarayana, Phanish and Torrent, Marc and Truflandier, Lionel and Windus, Theresa L. and Xu, Qimen and Yu, Victor W. -Z. and Perez, Danny}}, booktitle = {{arXiv:2209.12747}}, title = {{{Roadmap on Electronic Structure Codes in the Exascale Era}}}, year = {{2022}}, } @unpublished{32404, abstract = {{The CP2K program package, which can be considered as the swiss army knife of atomistic simulations, is presented with a special emphasis on ab-initio molecular dynamics using the second-generation Car-Parrinello method. After outlining current and near-term development efforts with regards to massively parallel low-scaling post-Hartree-Fock and eigenvalue solvers, novel approaches on how we plan to take full advantage of future low-precision hardware architectures are introduced. Our focus here is on combining our submatrix method with the approximate computing paradigm to address the immanent exascale era.}}, author = {{Kühne, Thomas and Plessl, Christian and Schade, Robert and Schütt, Ole}}, booktitle = {{arXiv:2205.14741}}, title = {{{CP2K on the road to exascale}}}, year = {{2022}}, } @article{33226, abstract = {{A parallel hybrid quantum-classical algorithm for the solution of the quantum-chemical ground-state energy problem on gate-based quantum computers is presented. This approach is based on the reduced density-matrix functional theory (RDMFT) formulation of the electronic structure problem. For that purpose, the density-matrix functional of the full system is decomposed into an indirectly coupled sum of density-matrix functionals for all its subsystems using the adaptive cluster approximation to RDMFT. The approximations involved in the decomposition and the adaptive cluster approximation itself can be systematically converged to the exact result. The solutions for the density-matrix functionals of the effective subsystems involves a constrained minimization over many-particle states that are approximated by parametrized trial states on the quantum computer similarly to the variational quantum eigensolver. The independence of the density-matrix functionals of the effective subsystems introduces a new level of parallelization and allows for the computational treatment of much larger molecules on a quantum computer with a given qubit count. In addition, for the proposed algorithm techniques are presented to reduce the qubit count, the number of quantum programs, as well as its depth. The evaluation of a density-matrix functional as the essential part of our approach is demonstrated for Hubbard-like systems on IBM quantum computers based on superconducting transmon qubits.}}, author = {{Schade, Robert and Bauer, Carsten and Tamoev, Konstantin and Mazur, Lukas and Plessl, Christian and Kühne, Thomas}}, journal = {{Phys. Rev. Research}}, pages = {{033160}}, publisher = {{American Physical Society}}, title = {{{Parallel quantum chemistry on noisy intermediate-scale quantum computers}}}, doi = {{10.1103/PhysRevResearch.4.033160}}, volume = {{4}}, year = {{2022}}, } @unpublished{46275, abstract = {{Electronic structure calculations have been instrumental in providing many important insights into a range of physical and chemical properties of various molecular and solid-state systems. Their importance to various fields, including materials science, chemical sciences, computational chemistry and device physics, is underscored by the large fraction of available public supercomputing resources devoted to these calculations. As we enter the exascale era, exciting new opportunities to increase simulation numbers, sizes, and accuracies present themselves. In order to realize these promises, the community of electronic structure software developers will however first have to tackle a number of challenges pertaining to the efficient use of new architectures that will rely heavily on massive parallelism and hardware accelerators. This roadmap provides a broad overview of the state-of-the-art in electronic structure calculations and of the various new directions being pursued by the community. It covers 14 electronic structure codes, presenting their current status, their development priorities over the next five years, and their plans towards tackling the challenges and leveraging the opportunities presented by the advent of exascale computing.}}, author = {{Gavini, Vikram and Baroni, Stefano and Blum, Volker and Bowler, David R. and Buccheri, Alexander and Chelikowsky, James R. and Das, Sambit and Dawson, William and Delugas, Pietro and Dogan, Mehmet and Draxl, Claudia and Galli, Giulia and Genovese, Luigi and Giannozzi, Paolo and Giantomassi, Matteo and Gonze, Xavier and Govoni, Marco and Gulans, Andris and Gygi, François and Herbert, John M. and Kokott, Sebastian and Kühne, Thomas and Liou, Kai-Hsin and Miyazaki, Tsuyoshi and Motamarri, Phani and Nakata, Ayako and Pask, John E. and Plessl, Christian and Ratcliff, Laura E. and Richard, Ryan M. and Rossi, Mariana and Schade, Robert and Scheffler, Matthias and Schütt, Ole and Suryanarayana, Phanish and Torrent, Marc and Truflandier, Lionel and Windus, Theresa L. and Xu, Qimen and Yu, Victor W. -Z. and Perez, Danny}}, booktitle = {{arXiv:2209.12747}}, title = {{{Roadmap on Electronic Structure Codes in the Exascale Era}}}, year = {{2022}}, } @article{33684, author = {{Schade, Robert and Kenter, Tobias and Elgabarty, Hossam and Lass, Michael and Schütt, Ole and Lazzaro, Alfio and Pabst, Hans and Mohr, Stephan and Hutter, Jürg and Kühne, Thomas and Plessl, Christian}}, issn = {{0167-8191}}, journal = {{Parallel Computing}}, keywords = {{Artificial Intelligence, Computer Graphics and Computer-Aided Design, Computer Networks and Communications, Hardware and Architecture, Theoretical Computer Science, Software}}, publisher = {{Elsevier BV}}, title = {{{Towards electronic structure-based ab-initio molecular dynamics simulations with hundreds of millions of atoms}}}, doi = {{10.1016/j.parco.2022.102920}}, volume = {{111}}, year = {{2022}}, } @article{33687, author = {{Odziomek, Mateusz and Giusto, Paolo and Kossmann, Janina and Tarakina, Nadezda V. and Heske, Julian Joachim and Rivadeneira, Salvador M. and Keil, Waldemar and Schmidt, Claudia and Mazzanti, Stefano and Savateev, Oleksandr and Perdigón‐Toro, Lorena and Neher, Dieter and Kühne, Thomas and Antonietti, Markus and López‐Salas, Nieves}}, issn = {{0935-9648}}, journal = {{Advanced Materials}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science}}, number = {{40}}, publisher = {{Wiley}}, title = {{{“Red Carbon”: A Rediscovered Covalent Crystalline Semiconductor}}}, doi = {{10.1002/adma.202206405}}, volume = {{34}}, year = {{2022}}, } @article{21207, abstract = {{Simple thermal treatment of guanine at temperatures ranging from 600 to 700 °C leads to C1N1 condensates with unprecedented CO2/N2 selectivity when compared to other carbonaceous solid sorbents. Increasing the surface area of the CN condensates in the presence of ZnCl2 salt melts enhances the amount of CO2 adsorbed while preserving the high selectivity values and C1N1 structure. Results indicate that these new materials show a sorption mechanism a step closer to that of natural CO2 caption proteins and based on metal free structural cryptopores.}}, author = {{Kossmann, Janina and Piankova, Diana and V. Tarakina, Nadezda and Heske, Julian Joachim and Kühne, Thomas and Schmidt, Johannes and Antonietti, Markus and López-Salas, Nieves}}, issn = {{0008-6223}}, journal = {{Carbon}}, keywords = {{CN, Cryptopores, Carbon dioxide capture}}, pages = {{497--505}}, title = {{{Guanine condensates as covalent materials and the concept of cryptopores}}}, doi = {{https://doi.org/10.1016/j.carbon.2020.10.047}}, volume = {{172}}, year = {{2021}}, } @article{22220, abstract = {{Abstract Developing resource-abundant and sustainable metal-free bifunctional oxygen electrocatalysts is essential for the practical application of zinc–air batteries (ZABs). 2D black phosphorus (BP) with fully exposed atoms and active lone pair electrons can be promising for oxygen electrocatalysts, which, however, suffers from low catalytic activity and poor electrochemical stability. Herein, guided by density functional theory (DFT) calculations, an efficient metal-free electrocatalyst is demonstrated via covalently bonding BP nanosheets with graphitic carbon nitride (denoted BP-CN-c). The polarized PN covalent bonds in BP-CN-c can efficiently regulate the electron transfer from BP to graphitic carbon nitride and significantly promote the OOH* adsorption on phosphorus atoms. Impressively, the oxygen evolution reaction performance of BP-CN-c (overpotential of 350 mV at 10 mA cm−2, 90\% retention after 10 h operation) represents the state-of-the-art among the reported BP-based metal-free catalysts. Additionally, BP-CN-c exhibits a small half-wave overpotential of 390 mV for oxygen reduction reaction, representing the first bifunctional BP-based metal-free oxygen catalyst. Moreover, ZABs are assembled incorporating BP-CN-c cathodes, delivering a substantially higher peak power density (168.3 mW cm−2) than the Pt/C+RuO2-based ZABs (101.3 mW cm−2). The acquired insights into interfacial covalent bonds pave the way for the rational design of new and affordable metal-free catalysts.}}, author = {{Wang, Xia and Kormath Madam Raghupathy, Ramya and Querebillo, Christine Joy and Liao, Zhongquan and Li, Dongqi and Lin, Kui and Hantusch, Martin and Sofer, Zdeněk and Li, Baohua and Zschech, Ehrenfried and Weidinger, Inez M. and Kühne, Thomas and Mirhosseini, Hossein and Yu, Minghao and Feng, Xinliang}}, journal = {{Advanced Materials}}, keywords = {{2D materials, bifunctional oxygen electrocatalysts, black phosphorus, oxygen evolution reaction, zinc–air batteries}}, number = {{20}}, pages = {{2008752}}, title = {{{Interfacial Covalent Bonds Regulated Electron-Deficient 2D Black Phosphorus for Electrocatalytic Oxygen Reactions}}}, doi = {{https://doi.org/10.1002/adma.202008752}}, volume = {{33}}, year = {{2021}}, } @article{29700, abstract = {{We have carried out an extensive search for stable polymorphs of carbon nitride with C3N5 stoichiometry using the minima hopping method. Contrary to the widely held opinion that stacked{,} planar{,} graphite-like structures are energetically the most stable carbon nitride polymorphs for various nitrogen contents{,} we find that this does not apply for nitrogen-rich materials owing to the high abundance of N–N bonds. In fact{,} our results disclose novel morphologies with moieties not previously considered for C3N5. We demonstrate that nitrogen-rich compounds crystallize in a large variety of different structures due to particular characteristics of their energy landscapes. The newly found low-energy structures of C3N5 have band gaps within good agreement with the values measured in experimental studies.}}, author = {{Ghasemi, Alireza and Mirhosseini, Hossein and Kühne, Thomas}}, journal = {{Phys. Chem. Chem. Phys.}}, pages = {{6422--6432}}, publisher = {{The Royal Society of Chemistry}}, title = {{{Thermodynamically stable polymorphs of nitrogen-rich carbon nitrides: a C3N5 study}}}, doi = {{10.1039/D0CP06185A}}, volume = {{23}}, year = {{2021}}, } @article{33653, author = {{Gurinov, Andrei and Sieland, Benedikt and Kuzhelev, Andrey and Elgabarty, Hossam and Kühne, Thomas and Prisner, Thomas and Paradies, Jan and Baldus, Marc and Ivanov, Konstantin L. and Pylaeva, Svetlana}}, issn = {{1433-7851}}, journal = {{Angewandte Chemie International Edition}}, keywords = {{General Chemistry, Catalysis}}, number = {{28}}, pages = {{15371--15375}}, publisher = {{Wiley}}, title = {{{Mixed‐Valence Compounds as Polarizing Agents for Overhauser Dynamic Nuclear Polarization in Solids}}}, doi = {{10.1002/anie.202103215}}, volume = {{60}}, year = {{2021}}, } @article{33643, abstract = {{The origin of strong interactions between water molecules and porous C2N surfaces is investigated by using a combination of model materials, volumetric physisorption measurements, solid-state NMR spectroscopy, and DFT calculations.}}, author = {{Heske, Julian Joachim and Walczak, Ralf and Epping, Jan D. and Youk, Sol and Sahoo, Sudhir K. and Antonietti, Markus and Kühne, Thomas and Oschatz, Martin}}, issn = {{2050-7488}}, journal = {{Journal of Materials Chemistry A}}, keywords = {{General Materials Science, Renewable Energy, Sustainability and the Environment, General Chemistry}}, number = {{39}}, pages = {{22563--22572}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{When water becomes an integral part of carbon – combining theory and experiment to understand the zeolite-like water adsorption properties of porous C2N materials}}}, doi = {{10.1039/d1ta05122a}}, volume = {{9}}, year = {{2021}}, } @article{33645, abstract = {{AbstractVibrational sum-frequency generation (vSFG) spectroscopy allows the study of the structure and dynamics of interfacial systems. In the present work, we provide a simple recipe, based on a narrowband IR pump and broadband vSFG probe technique, to computationally obtain the two-dimensional vSFG spectrum of water molecules at the air–water interface. Using this technique, to study the time-dependent spectral evolution of hydrogen-bonded and free water molecules, we demonstrate that at the interface, the vibrational spectral dynamics of the free OH bond is faster than that of the bonded OH mode.}}, author = {{Ojha, Deepak and Kühne, Thomas}}, issn = {{2045-2322}}, journal = {{Scientific Reports}}, keywords = {{Multidisciplinary}}, number = {{1}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Hydrogen bond dynamics of interfacial water molecules revealed from two-dimensional vibrational sum-frequency generation spectroscopy}}}, doi = {{10.1038/s41598-021-81635-4}}, volume = {{11}}, year = {{2021}}, } @article{33644, author = {{Pylaeva, Svetlana and Marx, Patrick and Singh, Gurjot and Kühne, Thomas and Roemelt, Michael and Elgabarty, Hossam}}, issn = {{1089-5639}}, journal = {{The Journal of Physical Chemistry A}}, keywords = {{Physical and Theoretical Chemistry}}, number = {{3}}, pages = {{867--874}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Organic Mixed-Valence Compounds and the Overhauser Effect in Insulating Solids}}}, doi = {{10.1021/acs.jpca.0c11296}}, volume = {{125}}, year = {{2021}}, } @article{33649, author = {{Kessler, Jan and Calcavecchia, Francesco and Kühne, Thomas}}, issn = {{2513-0390}}, journal = {{Advanced Theory and Simulations}}, keywords = {{Multidisciplinary, Modeling and Simulation, Numerical Analysis, Statistics and Probability}}, number = {{4}}, publisher = {{Wiley}}, title = {{{Artificial Neural Networks as Trial Wave Functions for Quantum Monte Carlo}}}, doi = {{10.1002/adts.202000269}}, volume = {{4}}, year = {{2021}}, } @article{33648, author = {{Ghasemi, Alireza and Kühne, Thomas}}, issn = {{0021-9606}}, journal = {{The Journal of Chemical Physics}}, keywords = {{Physical and Theoretical Chemistry, General Physics and Astronomy}}, number = {{7}}, publisher = {{AIP Publishing}}, title = {{{Artificial neural networks for the kinetic energy functional of non-interacting fermions}}}, doi = {{10.1063/5.0037319}}, volume = {{154}}, year = {{2021}}, } @article{33655, abstract = {{Abstract Dual-ion batteries are considered to be an emerging viable energy storage technology owing to their safety, high power capability, low cost, and scalability. Intercalation of anions into a graphite positive electrode provides high operating voltage and improved energy density to such dual-ion batteries. In this work, we have performed a combinatorial study of graphite intercalation compounds considering four anions, namely hexafluorophosphate (PF 6 − ), perchlorate (ClO 4 − ), bis(fluorosulfonyl)imide (FSI−), and bis(trifluoromethanesulfonyl)imide (TFSI−), via first-principles calculations. The structural properties and energetics of the intercalation compounds are compared based on different sizes, geometries, and the physical and chemical properties of the intercalated anions. The staging mechanism of anion intercalation into graphite and the specific capacities, and voltage profiles of the intercalated compounds are investigated. A comparison regarding battery electrochemistry is also done with available experimental observations. Our calculated intercalation energies and voltage profiles show that the initial anion intercalation into graphite is less favorable than subsequent ones for all the anions considered in this study. Although the effect of the size of anions in a graphite cathode on various properties of the intercalated compounds is not as significant as the size of cations in a graphite anode, some distinction between the studied anions can still be made. Among the studied anions, the intercalation compounds based on PF 6 − are the most stable ones. These PF 6 − anions cause relatively small structural deformations of the graphite and have the highest oxidative ability, highest onset voltage, and highest diffusion barrier along the graphene sheets. The overall small diffusion barriers of the anions within graphite explain the high rate capability of dual-ion batteries.}}, author = {{Chugh, Manjusha and Jain, Mitisha and Wang, Gang and Nia, Ali Shaygan and Mirhosseini, Hossein and Kühne, Thomas}}, issn = {{2053-1591}}, journal = {{Materials Research Express}}, keywords = {{Metals and Alloys, Polymers and Plastics, Surfaces, Coatings and Films, Biomaterials, Electronic, Optical and Magnetic Materials}}, number = {{8}}, publisher = {{IOP Publishing}}, title = {{{A combinatorial study of electrochemical anion intercalation into graphite}}}, doi = {{10.1088/2053-1591/ac1965}}, volume = {{8}}, year = {{2021}}, } @article{33658, abstract = {{We demonstrate how to fully ascribe Raman peaks simulated using ab initio molecular dynamics to specific vibrations in the structure at finite temperatures by means of Wannier functions. Here, we adopt our newly introduced method for the simulation of the Raman spectra in which the total polarizability of the system is expressed as a sum over Wannier polarizabilities. The assignment is then based on the calculation of partial Raman activities arising from self- and/or cross-correlations between different types of Wannier functions in the system. Different types of Wannier functions can be distinguished based on their spatial spread. To demonstrate the predictive power of this approach, we applied it to the case of a cyclohexane molecule in the gas phase and were able to fully assign the simulated Raman peaks.}}, author = {{Partovi-Azar, Pouya and Kühne, Thomas}}, issn = {{2072-666X}}, journal = {{Micromachines}}, keywords = {{Electrical and Electronic Engineering, Mechanical Engineering, Control and Systems Engineering}}, number = {{10}}, publisher = {{MDPI AG}}, title = {{{Full Assignment of Ab-Initio Raman Spectra at Finite Temperatures Using Wannier Polarizabilities: Application to Cyclohexane Molecule in Gas Phase}}}, doi = {{10.3390/mi12101212}}, volume = {{12}}, year = {{2021}}, }