Article
Chemistry, Physical
Joshua Finkelstein, Justin S. Smith, Susan M. Mniszewski, Kipton Barros, Christian F. A. Negre, Emanuel H. Rubensson, Anders M. N. Niklasson
Summary: A second-order recursive Fermi-operator expansion scheme using mixed precision floating point operations on tensor core units is presented, achieving over 100 teraFLOPS of performance for half-precision floating point operations on Nvidia's A100. The scheme is formulated as a generalized, differentiable deep neural network structure, accelerating convergence by optimizing weight and bias values, and optimizing coefficients of the expansion to accurately represent fractional occupation numbers of electronic states at finite temperatures using a machine learning approach.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Jorge Alfonso Charry Martinez, Matteo Barborini, Alexandre Tkatchenko
Summary: The article introduces an accurate, efficient, and transferable variational ansatz based on a combination of electron-positron geminal orbitals and a Jastrow factor. This ansatz explicitly includes the electron-positron correlations and is optimized using variational Monte Carlo. The approach is applied to calculate binding energies for various atomic and molecular systems, showing improved accuracy compared to previous calculations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Materials Science, Multidisciplinary
Rafael A. Macedo, Flavia B. Ramos, Rodrigo G. Pereira
Summary: This study focuses on the problem of time-reversal symmetry breaking in quantum spin systems and presents a method to construct one-dimensional anisotropic spin models. It introduces the phenomenon of Landau-forbidden continuous phase transition and provides a concrete example. The results show that the transition between chiral and magnetic phases exhibits an emergent U(1) symmetry, with excitations resembling mobile defects binding fermionic modes.
Article
Biochemical Research Methods
Rosana M. Lobayan, Roberto C. Bochicchio, Alejandro D. Marturet
Summary: This report deeply explores electron rearrangements in a chemical reaction case study. It focuses on the subtle description of electron distribution at both equilibrium and non-equilibrium conformations, particularly the determination of complex interaction patterns of two or four electrons in three centers. The results highlight the crucial importance of these interaction patterns in the charge transference process.
JOURNAL OF MOLECULAR GRAPHICS & MODELLING
(2022)
Article
Chemistry, Multidisciplinary
Jose Manuel Guevara-Vela, Kristopher Hess, Tomas Rocha-Rinza, Angel Martin Pendas, Marcos Flores-Alamo, Guillermo Moreno-Alcantar
Summary: Crystallographic distances and electron density of bi- and tri-nuclear gold(I) compounds show that multiple Au…Au interactions increase their individual strength in the order of 0.9-2.9 kcal mol(-1). This behavior was observed experimentally and theoretically in multinuclear systems, confirming a novel important cooperative character in aurophilic contacts.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Yumin Yang, Shuang Feng, Jianan Su, Yutong Gong, Junjie Wang
Summary: The effects of modification strategies on the activation of nitrogen molecules and the electrocatalytic nitrogen reduction reaction (eNRR) were systematically studied. It was found that Mo(II)-Fe2(DOAnBDC) and Mo(II)-Fe2F2(BBTA) are potential high-performance eNRR electrocatalysts, with their activity related to the arrangement of molybdenum's d orbitals and charge transfer.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Sofia Lindblad, Flora Boroka Nemeth, Tamas Foldes, Daniel von der Heiden, Herh G. Vang, Zakarias L. Driscoll, Emily R. Gonnering, Imre Papai, Nathan Bowling, Mate Erdelyi
Summary: (English Summary)
The study investigates the stability and reactivity of halonium ions stabilized by [bis(pyridine)iodine(I)](+) complexes. Factors such as chelation, strain, steric hindrance, and electrostatic interaction were found to influence the structure and release rate of these ions. Additionally, the presence of an electron-rich moiety nearby the [N-I-N](+) motif was observed to increase the iodenium release rate.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Lucas de Azevedo Santos, Teodorico C. Ramalho, Trevor A. Hamlin, F. Matthias Bickelhaupt
Summary: Quantum chemical methods were used to analyze the nature and origin of directionality in pnictogen, chalcogen, and halogen bonds in F(m)Z·F- complexes. The results show that covalent interactions, in addition to electrostatic attraction, contribute significantly to the bond energy. Interestingly, despite electrostatic interactions favoring bending, all these bonds exhibit directionality, which contradicts the sigma-hole model. These findings are applicable to various complexes, including ClI·NH3, HClTe·NH3, and H2ClSb·NH3.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Katerina P. Hilleke, Eva Zurek
Summary: The study explains the structure and stability of metal hydride phases using Density Functional Theory-Chemical Pressure (DFT-CP) method, revealing the reasons why certain elements adopt specific structure types and how internal pressure leads to the opening of H-24 polyhedra. The stability of phases is enhanced by filling the shared hydrogen network with additional atoms.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Physics, Multidisciplinary
Ari M. Turner, Erez Berg, Ady Stern
Summary: In this study, the stability of fragile topological bands protected by space-time inversion symmetry under strong electron-electron interactions is investigated. It is found that when these fragile bands are half filled, interactions can open a gap in the many-body spectrum without breaking any symmetry or mixing degrees of freedom from remote bands. The resulting ground state is not topologically ordered. The formation of fermionic bound states known as trions is crucial for this result, which may be relevant to recent experiments in magic angle twisted bilayer graphene at charge neutrality.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Albert Th Thorhallsson, Ragnar Bjornsson
Summary: This study explores the energy surface of the E-2 state of FeMoco and identifies two possible contender models: one containing a bridging hydride and an open sulfide-bridge (hydride model), and the other featuring a protonated belt-sulfide and a reduced cofactor without a hydride (non-hydride model).
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Zoraida Sandoval-Olivares, Eduardo Solis-Cespedes, Dayan Paez-Hernandez
Summary: The antiferromagnetic coupling supported by metallophilic interactions has been studied using broken symmetry approach and multiconfigurational calculations. The results show that axial ligands with a pure sigma-donor character strengthen the antiferromagnetic coupling. The interaction between magnetic orbitals and low-level excitations in the region of Pt atoms also plays a role in enhancing the antiferromagnetic coupling.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Rafael Islas, David Arias-Olivares, Andres Becerra-Buitrago, Luis Carlos Garcia-Sanchez, Lya Neftaly Mendez-Ayon, Bernardo Zuniga-Gutierrez
Summary: In this study, the electronic delocalization of metallacycles based on borazine was analyzed using magnetic and electronic criteria. The results showed that metal-N bonded borazines can be classified as delocalized compounds, while metal-B bonded borazines can be classified as nonaromatic or weak aromatic compounds.
Review
Chemistry, Physical
Prachi Sharma, Jie J. Bao, Donald G. Truhlar, Laura Gagliardi
Summary: Kohn-Sham density functional theory is less accurate for strongly correlated systems compared to weakly correlated systems. The available functionals for spin densities do not accurately predict energies for strongly correlated systems when using multiconfigurational wave functions with spin symmetry. Multiconfiguration pair-density functional theory overcomes these limitations by using a functional of the total density and on-top pair density, allowing efficient calculation of energy for strongly correlated systems.
ANNUAL REVIEW OF PHYSICAL CHEMISTRY, VOL 72
(2021)
Article
Chemistry, Multidisciplinary
Kaiyue Zhang, Jing Wang, Weining Zhang, Hongfei Yin, Jiuhui Han, Xiaoyong Yang, Weiliu Fan, Yongzheng Zhang, Ping Zhang
Summary: Carbon-encapsulated CuNi nanoparticles anchored on nitrogen-doped nanoporous graphene (CuNi@C/N-npG) composite are developed, exhibiting excellent CO2 reduction performance with higher ethanol Faradaic efficiency (FEethanol >= 60%) in a wide potential window (600 mV). The optimal cathodic energy efficiency (47.6%), Faradaic efficiency (84%), and selectivity (96.6%) are achieved at -0.78 V versus reversible hydrogen electrode (RHE). The study demonstrates that the stronger metal-support interaction (Ni-N-C) effectively regulates the surface electronic structure, enhancing the electron transfer and stabilizing the active sites (Cu-0-Cu delta+) on the surface of CuNi@C/N-npG, thus enabling controllable transition of reaction intermediates. This work may guide the design of electrocatalysts with high catalytic performance for CO2 reduction to C2+ products.
Article
Chemistry, Multidisciplinary
Michael M. Aristov, John W. Moore, John F. Berry
Summary: Through the use of Sketchfab website and smartphone application, we have successfully introduced 3D visual tools into the chemistry classroom, creating a free library of interactive 3D models covering various chemistry topics. Students can use these models to better understand concepts through hands-on exploration.
JOURNAL OF CHEMICAL EDUCATION
(2021)
Article
Chemistry, Inorganic & Nuclear
Michael D. Roy, Michael J. Trenerry, Biswash Thakuri, Samantha N. MacMillan, Matthew D. Liptak, Kyle M. Lancaster, John F. Berry
Summary: In this study, diruthenium paddlewheel complexes supported by electron-rich anilinopyridinate (Xap) ligands were synthesized, and the first in-depth structural and spectroscopic analysis of monocationic [Ru-2(Xap)(4)Cl]+ species in the Ru-2(6+) oxidation state was conducted. H-1 NMR spectroscopy proved to be highly informative for determining the isomerism of the Ru-2(5+) and Ru-2(6+) compounds. Electrochemical studies demonstrated the tunability of oxidation potentials by installing electron donating groups to the ligands, increasing accessibility of the Ru-2(6+) oxidation state.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Oskar Weser, Kai Guther, Khaldoon Ghanem, Giovanni Li Manni
Summary: The algorithm utilizes the FCIQMC algorithm based on Slater determinants as the eigensolver, allowing optimization of preselected truncated configuration interaction wave functions to reduce costs or explore specific electron correlation pathways. It supports selection of multiple active subspaces, occupation number constraints, and efficient encoding of constraints using precomputed probability distributions.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Multidisciplinary
Sungho Park, Amanda R. Corcos, Alexander N. Jambor, Tzuhsiung Yang, John F. Berry
Summary: Construction of nitrogen-nitrogen triple bonds via homocoupling of metal nitrides is a significant reaction relevant to a potential Nitrogen Economy. Room temperature photolysis of Ru-2(chp)(4)N-3 (chp(-) = 2-chloro-6-hydroxypyridinate) in CH2Cl2 produces N-2 via reductive coupling of Ru-2(chp)(4)N nitrido species. Computational analysis reveals that the nitride coupling transition state (TS) features an out-of-plane zigzag geometry instead of the anticipated planar zigzag TS.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Physics, Multidisciplinary
Nikolay A. Bogdanov, Giovanni Li Manni, Sandeep Sharma, Olle Gunnarsson, Ali Alavi
Summary: Cuprates exhibit exotic states due to the interplay between spin, charge, and orbital degrees of freedom. Ab initio calculations reveal that the orbital expansion mechanism plays a key role in the magnetic properties of cuprates. Additionally, the electronic properties of cuprates are highly sensitive to the presence and displacement of apical oxygens perpendicular to the CuO2 planes, influencing the nearest-neighbour superexchange antiferromagnetic coupling.
Article
Chemistry, Multidisciplinary
Michael M. Aristov, Han Geng, Alex Pavelic, John F. Berry
Summary: This article presents a growing library of 3D models that can be used for educational purposes in crystallography. These models offer significant advantages over traditional 2D depictions and can be accessed through computers and smartphones. The models have been created using Blender and uploaded to Sketchfab for easy distribution and viewing. Users are encouraged to download and modify the models to suit their needs.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2022)
Article
Chemistry, Inorganic & Nuclear
Daniel J. SantaLucia, Wenhui Hu, Denan Wang, Jier Huang, John F. Berry
Summary: Reaction of Co(II) nitrate with 2-methylimidazole(2mIm) leads to the formation of ZIF-67 with a pseudo-tetrahedral coordination geometry for Co(II) ions. Strong antiferromagnetic interactions between Co(II) ions mediated by the 2mIm ligands result in antiferromagnetic ordering at 22 K. The postsynthetic treatment of Co(II) ZIF-67 with 5-methyltetrazole (5mT) leads to the loss of crystallinity and magnetic order. The change in local structure and geometry of the Co(II) ions upon substitution is confirmed by various spectroscopic techniques. The increase in coordination number weakens the magnetic exchange interactions.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Eugenio Vitale, Giovanni Li Manni, Ali Alavi, Daniel Kats
Summary: A tailored approach based on the distinguishable E cluster method and the stochastic FCIQMC solver has been extended to open-shell molecular systems. The method was used to calculate spin gaps of Fe(II) complexes, showing that the tailored distinguishable cluster with singles and doubles gives more accurate results compared to the tailored coupled cluster with singles and doubles.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Oskar Weser, Niklas Liebermann, Daniel Kats, Ali Alavi, Giovanni Li Manni
Summary: In this article, a first-order spin penalty scheme is demonstrated to be efficiently applied to the Slater determinant based FCIQMC algorithm for spin purification. Two applications are presented to validate the scheme's validity and robustness. The strategy can be coupled to other algorithms and provides spin-adaptation and spin-resolved reduced density matrices, making it important for the investigation of spin-dependent properties.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Giovanni Li Manni, Daniel Kats, Niklas Liebermann
Summary: In this study, ground and excited electronic states of Heisenberg cluster models were characterized using the spin adapted Graphical Unitary Group Approach. It was found that an optimal lattice site ordering reflecting the internal symmetries of the model resulted in a unique block-diagonal structure of the Hamiltonian matrix in the spin-adapted basis. This block-diagonal structure allowed for the selective optimization of electronic excited states and the obtaining of more compact many-body wave functions.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Giovanni Li Manni, Ignacio Fdez. Galvan, Ali Alavi, Flavia Aleotti, Francesco Aquilante, Jochen Autschbach, Davide Avagliano, Alberto Baiardi, Jie J. Bao, Stefano Battaglia, Letitia Birnoschi, Alejandro Blanco-Gonzalez, Sergey I. Bokarev, Ria Broer, Roberto Cacciari, Paul B. Calio, Rebecca K. Carlson, Rafael Carvalho Couto, Luis Cerdan, Liviu F. Chibotaru, Nicholas F. Chilton, Jonathan Richard Church, Irene Conti, Sonia Coriani, Juliana Cuellar-Zuquin, Razan E. Daoud, Nike Dattani, Piero Decleva, Coen de Graaf, Mickael G. Delcey, Luca De Vico, Werner Dobrautz, Sijia S. Dong, Rulin Feng, Nicolas Ferre, Michael Filatov (Gulak), Laura Gagliardi, Marco Garavelli, Leticia Gonzalez, Yafu Guan, Meiyuan Guo, Matthew R. Hennefarth, Matthew R. Hermes, Chad E. Hoyer, Miquel Huix-Rotllant, Vishal Kumar Jaiswal, Andy Kaiser, Danil S. Kaliakin, Marjan Khamesian, Daniel S. King, Vladislav Kochetov, Marek Krosnicki, Arpit Arun Kumaar, Ernst D. Larsson, Susi Lehtola, Marie-Bernadette Lepetit, Hans Lischka, Pablo Lopez Rios, Marcus Lundberg, Dongxia Ma, Sebastian Mai, Philipp Marquetand, Isabella C. D. Merritt, Francesco Montorsi, Maximilian Morchen, Artur Nenov, Vu Ha Anh Nguyen, Yoshio Nishimoto, Meagan S. Oakley, Massimo Olivucci, Markus Oppel, Daniele Padula, Riddhish Pandharkar, Quan Manh Phung, Felix Plasser, Gerardo Raggi, Elisa Rebolini, Markus Reiher, Ivan Rivalta, Daniel Roca-Sanjuan, Thies Romig, Arta Anushirwan Safari, Aitor Sanchez-Mansilla, Andrew M. Sand, Igor Schapiro, Thais R. Scott, Javier Segarra-Marti, Francesco Segatta, Dumitru-Claudiu Sergentu, Prachi Sharma, Ron Shepard, Yinan Shu, Jakob K. Staab, Tjerk P. Straatsma, Lasse Kragh Sorensen, Bruno Nunes Cabral Tenorio, Donald G. Truhlar, Liviu Ungur, Morgane Vacher, Valera Veryazov, Torben Arne Voss, Oskar Weser, Dihua Wu, Xuchun Yang, David Yarkony, Chen Zhou, J. Patrick Zobel, Roland Lindh
Summary: This article describes the developments of the open-source OpenMolcas chemistry software environment since spring 2020, focusing on the novel functionalities in the stable branch and interfaces with other packages. These developments cover a wide range of topics in computational chemistry and provide an overview of the chemical phenomena and processes that OpenMolcas can address.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Ruocheng Han, Sandra Luber, Giovanni Li Manni
Summary: Strong electron correlation effects pose a major challenge in quantum chemistry. This study employs forefront techniques like density matrix renormalization group (DMRG), full configuration interaction quantum Monte Carlo (FCIQMC), and multiconfiguration pair-density functional theory (MCPDFT) to investigate magnetic interactions in a [Co(II)3Er(III)-(OR)4] model cubane water oxidation catalyst. The findings provide crucial insights on the spin interactions in this model system and its catalytic activity in the water-splitting reaction.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Giovanni Li Manni, Ignacio Fdez. Galvan, Ali Alavi, Flavia Aleotti, Francesco Aquilante, Jochen Autschbach, Davide Avagliano, Alberto Baiardi, Jie J. Bao, Stefano Battaglia, Letitia Birnoschi, Alejandro Blanco-Gonzalez, Sergey I. Bokarev, Ria Broer, Roberto Cacciari, Paul B. Calio, Rebecca K. Carlson, Rafael Carvalho Couto, Luis Cerdan, Liviu F. Chibotaru, Nicholas F. Chilton, Jonathan Richard Church, Irene Conti, Sonia Coriani, Juliana Cuellar-Zuquin, Razan E. Daoud, Nike Dattani, Piero Decleva, Coen de Graaf, Mickael G. Delcey, Luca De Vico, Werner Dobrautz, Sijia S. Dong, Rulin Feng, Nicolas Ferre, Michael Filatov(Gulak), Laura Gagliardi, Marco Garavelli, Leticia Gonzalez, Yafu Guan, Meiyuan Guo, Matthew R. Hennefarth, Matthew R. Hermes, Chad E. Hoyer, Miquel Huix-Rotllant, Vishal Kumar Jaiswal, Andy Kaiser, Danil S. Kaliakin, Marjan Khamesian, Daniel S. King, Vladislav Kochetov, Marek Krosnicki, Arpit Arun Kumaar, Ernst D. Larsson, Susi Lehtola, Marie-Bernadette Lepetit, Hans Lischka, Pablo Lopez Rios, Marcus Lundberg, Dongxia Ma, Sebastian Mai, Philipp Marquetand, Isabella C. D. Merritt, Francesco Montorsi, Maximilian Morchen, Artur Nenov, Vu Ha Anh Nguyen, Yoshio Nishimoto, Meagan S. Oakley, Massimo Olivucci, Markus Oppel, Daniele Padula, Riddhish Pandharkar, Quan Manh Phung, Felix Plasser, Gerardo Raggi, Elisa Rebolini, Markus Reiher, Ivan Rivalta, Daniel Roca-Sanjuan, Thies Romig, Arta Anushirwan Safari, Aitor Sanchez-Mansilla, Andrew M. Sand, Igor Schapiro, Thais R. Scott, Javier Segarra-Marti, Francesco Segatta, Dumitru-Claudiu Sergentu, Prachi Sharma, Ron Shepard, Yinan Shu, Jakob K. Staab, Tjerk P. Straatsma, Lasse Kragh Sorensen, Bruno Nunes Cabral Tenorio, Donald G. Truhlar, Liviu Ungur, Morgane Vacher, Valera Veryazov, Torben Arne Voss, Oskar Weser, Dihua Wu, Xuchun Yang, David Yarkony, Chen Zhou, J. Patrick Zobel, Roland Lindh
Summary: This article describes the recent developments in the open-source chemistry software environment, OpenMolcas, since spring 2020. It focuses on the new functionalities and interfaces with other packages. The article presents various topics in computational chemistry, including electronic structure theory, electronic spectroscopy simulations, molecular structure optimizations, ab initio molecular dynamics, and other new features. Overall, it highlights the capabilities of OpenMolcas in addressing chemical phenomena and processes, making it an attractive platform for advanced atomistic computer simulations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Materials Science, Multidisciplinary
Werner Dobrautz, Vamshi M. Katukuri, Nikolay A. Bogdanov, Daniel Kats, Giovanni Li Manni, Ali Alavi
Summary: This study uses a novel approach that combines unitary and symmetric groups to investigate the spin-1/2 Heisenberg model and related Fermionic systems. The results show that combining these groups leads to a more compact representation of the ground-state wave function. Additionally, the compression of the wave function allows for the study of larger lattices.
Article
Chemistry, Inorganic & Nuclear
Alessio Nicolini, Marco Affronte, Daniel J. SantaLucia, Marco Borsari, Benjamin Cahier, Matteo Caleffi, Antonio Ranieri, John F. Berry, Andrea Cornia
Summary: Iron-based extended metal atom chains show potential as high-spin molecules and candidate single-molecule magnets. Tetrairon(ii) halide-capped complexes were compared in terms of their structural, electrochemical, and magnetic characteristics. The electronic structure of iron(ii) ions in each compound displayed distinct magnetic anisotropy, contributing to the observed magnetic behaviors. The competition between super-exchange interactions and noncollinear anisotropies at metal sites results in the weakly magnetic ground state observed in both derivatives, explaining their single-molecule magnet behavior.
DALTON TRANSACTIONS
(2021)