Article
Chemistry, Applied
Miroslav Rubes, Michal Trachta, Jan Vaculik, Roman Bulanek, Ota Bludsky
Summary: The diversity of IR band shapes in the OH stretching region of zeolite frameworks (FER, TON, CHA, and IFR) was investigated using FT-IR spectroscopy and DFT calculations. The analysis of isolated Brunsted acid sites revealed the importance of mutual BAS interactions in some zeolites. Extended models should be used to accurately simulate the distribution of heteroatoms in these materials for adsorption and catalytic property calculations.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Applied
Miroslav Rubes, Eva Koudelkova, Jan Vaculik, Michal Trachta, Roman Bulanek, Ota Bludsky
Summary: The distribution of Al in H-MOR zeolites exhibits non-statistical behavior, while the interaction of adjacent Brønsted acid sites in samples with lower Si/Al ratios leads to changes in populations of different sites. The excellent agreement between calculated CO adsorption enthalpies and experimental measurements supports the interpretation of the data.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Physical
J. E. Galvan, E. Contreras Aguilar, S. E. Ulic, R. D. I. Molina, M. E. Arena, S. B. Diaz, A. Ben Altabef, M. E. Tuttolomondo
Summary: This study investigates the reactivity-structure connection mechanism of oxoesters and thioesters through conformation exploration and analysis of different energy interactions. The study also demonstrates the inhibitory effects of TFMSMS on the growth and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus strains, and reveals its interference with the Quorum sensing system in Gram-negative bacteria for the first time.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Biochemistry & Molecular Biology
Fedor Y. Naumkin
Summary: Complexes of metal atoms with organic molecules are a class of systems with numerous applications, such as in metal-organic interfaces and organometallic chemistry. This study systematically investigates complexes with second-group metals, focusing on their structure, stability, charge distribution, polarity, and IR spectra. Three groups of isomers with different stability and physisorption or chemisorption characteristics are identified. Nonadditive stabilization in ternary systems and shape alterations of the aromatic component for different isomers and system sizes are also observed.
Article
Chemistry, Physical
David Ochoa-Resendiz, Antonio Gamboa-Suarez, Ramon Hernandez-Lamoneda
Summary: This article presents a detailed theoretical characterization of the structure and interactions in dichlorine clathrate hydrate cages, including the influence of halogen bonding and rotational motion. Monte Carlo simulations and energy decomposition analysis are used to further understand these effects.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Qian-Rui Huang, Ryunosuke Shishido, Chih-Kai Lin, Chen-Wei Tsai, Jake A. Tan, Asuka Fujii, Jer-Lai Kuo
Summary: The study analyzed the infrared spectra of a series of asymmetric proton-bound dimers with protonated trimethylamine as the proton donor, revealing a red shift in the N-H+ stretching mode frequency as the proton affinity of acceptors increases. Despite the expected pattern, the observed band showed a peculiar splitting of around 300 cm(-1) with intensity resembling a two-level system. Theoretical investigation attributed this band splitting to strong coupling between the proton stretching mode and overtone states of proton bending modes, known as Fermi resonance, providing a general theoretical model linking the strong coupling to a quasi-two-level system intrinsic to proton motions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Juan J. J. Aucar, Alejandro F. F. Maldonado, Juan I. I. Melo
Summary: In this work, relativistic corrections to the electric field gradient (EFG) are presented, including spin-dependent corrections for the first time. The results show that these new corrections significantly improve the performance of the existing method and are in close agreement with calculations at the four-component Dirac-Hartree-Fock (4c-DHF) level. The accuracy of the EFG values obtained with this new method allows for the analysis of the electronic origin of relativistic effects using well-known nonrelativistic operators.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Ilya S. Sosulin, Mariia A. Lukianova, Anastasia D. Volosatova, Vladimir D. Drabkin, Svetlana V. Kameneva
Summary: Hydrogen bonding between saturated alkanes and HX is a unique type of interaction. Experimental and ab initio studies on the HCN...C2H6 complex show that only one structure is stabilized under experimental conditions, in good agreement with previous rotational spectroscopy studies.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Chemistry, Physical
Mitsuhiko Miyazaki, Megumi Ono, Remina Otsuka, Otto Dopfer, Masaaki Fujii
Summary: Van der Waals clusters composed of He and aromatic molecules were characterized using UV and IR spectroscopies. The clusters exhibited pi-bound structures and the He atoms had negligible effects on molecular vibrations.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Guohai Deng, Sudip Pan, Jiaye Jin, Guanjun Wang, Lili Zhao, Mingfei Zhou, Gernot Frenking
Summary: Two structural isomers containing five second-row element atoms with 24 valence electrons were generated and identified through matrix-isolation IR spectroscopy and quantum chemical calculations. The OCBNO complex rearranges to the more stable OBNCO isomer upon UV excitation, with bonding analysis indicating interactions between a triplet-state boron cation and CO/NO- ligands.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Jing Shang, Congxin Xia, Chun Tang, Chun Li, Yandong Ma, Yuantong Gu, Liangzhi Kou
Summary: The bending deformation of AgBiP2Se6 monolayers can manipulate the polarization direction and domain size, significantly improving the ferroelectric stability. This mechano-ferroelectric coupling represents a new mechanism for stabilization and polarization flip in 2D ferroelectrics, with potential applications in next-generation non-volatile storage devices.
NANOSCALE HORIZONS
(2021)
Article
Chemistry, Physical
Tim Graubner, Antti J. Karttunen, Florian Kraus
Summary: Quantum chemical methods were used to study the molecular structure and anharmonic IR spectra of closed-shell molecular hexafluorides MF6 (M=S, Se, Te, Xe, Mo, W, U). The study investigated the molecular structures and harmonic frequencies using Density Functional Theory (DFT) and spin-orbit coupling. Anharmonic frequencies and IR intensities were calculated with the CCSD(T) coupled cluster method and compared with recorded IR spectra. The study also predicted the existence of NdF6 molecule for the first time and characterized its bonding situation using intrinsic bond orbital (IBO) analyses.
Article
Materials Science, Multidisciplinary
Lu Wu, Vasyl O. Kharchenko, Xianggang Kong, Dmitrii O. Kharchenko
Summary: This article investigates the stability of small vacancy clusters in zirconium-based alloys with small concentration of alloying additions through ab-initio calculations. The study analyzes the formation energy of different size vacancy clusters and the binding energy between solute and vacancy clusters to understand the ability of alloying elements to localize small vacancy clusters. Insights are provided into the effect of alloying elements on vacancy clustering in zirconium-based alloys.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
S. S. Huang, H. Q. Guan, Z. H. Zhong, M. Miyamoto, Q. Xu
Summary: Recent studies have found that equiatomic CoCrFeMnNi high-entropy alloy (HEA) exhibits excellent mechanical properties and irradiation resistance. However, when subjected to neutron irradiation, helium (He) is always generated as a byproduct. This study compares the irradiation resistance of thin-film CoCrFeMnNi HEA samples irradiated with He ions at 773 K to that of stainless steel 304 (SS304), which has the same crystal structure. Both alloys showed the formation of He bubbles during irradiation, but the CoCrFeMnNi HEA had a lower He bubble density compared to SS304 under the same exposure conditions. First-principles calculations were used to simulate the effect of He on the formation of vacancy clusters in the CoCrFeMnNi HEA, and the results demonstrated that the presence of He significantly enhanced the stability of vacancy clusters. Therefore, even in the CoCrFeMnNi HEA, irradiation resulted in the formation of stable He-vacancy clusters, which decreased the irradiation resistance.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Xiao-Long Zhang, Shu-Bin Yang, Dan Hou, Hui Li
Summary: A new five-dimensional potential energy surface (PES) for H2O-Kr, including the intramolecular 2OH overtone state of the H2O monomer, is presented. The intermolecular potential energies were evaluated using explicitly correlated coupled cluster theory, and the resulting PESs were fitted to obtain vibrationally averaged analytical intermolecular PESs. These PESs were then used to calculate the rovibrational energy levels of H2O-Kr complexes, with excellent agreement with experimental values. This study provides reliable theoretical guidance for future infrared overtone spectroscopy of H2O-Kr.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Gergely Barcza, Viktor Ivady, Tibor Szilvasi, Marton Voros, Libor Veis, Adam Gali, Ors Legeza
Summary: This study analyzes the numerical aspects of the inherent multireference density matrix renormalization group (DMRG) calculations on top of the periodic Kohn-Sham density functional theory using the complete active space approach. Results show excellent consistency of the DMRG energy spectrum in terms of sample size, basis size, and active space selection protocol, with good agreement with results obtained from standard quantum chemical calculations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Multidisciplinary
Jiri Brabec, Jan Brandejs, Karol Kowalski, Sotiris Xantheas, Ors Legeza, Libor Veis
Summary: This study represents the first attempt to use a super-computer platform for QC-DMRG calculations, showing the scalability of the parallel approach up to approximately 2000 CPU cores in the largest calculation, with testing on three different molecules.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2021)
Article
Chemistry, Physical
Ana Sanchez-Grande, Jose Urgel, Libor Veis, Shayan Edalatmanesh, Jose Santos, Koen Lauwaet, Pingo Mutombo, Jose M. Gallego, Jiri Brabec, Pavel Beran, Dana Nachtigallova, Rodolfo Miranda, Nazario Martin, Pavel Jelinek, David Ecija
Summary: Polycyclic aromatic hydrocarbons (PAHs) are organic compounds with multiple fused aromatic rings, some of which exhibit open-shell magnetic ground states. Recent research has focused on the synthesis and study of acene and fused acene (periacene) families, with experimental evidence of a magnetic ground state reported for isolated peripentacene molecules. This discovery contributes to a better understanding of organic compounds with magnetic properties, particularly in the development of carbon-based spintronic devices.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Jie Su, Wei Fan, Pingo Mutombo, Xinnan Peng, Shaotang Song, Martin Ondracek, Pavlo Golub, Jiri Brabec, Libor Veis, Mykola Telychko, Pavel Jelinek, Jishan Wu, Jiong Lu
Summary: This study reports the synthesis of an open-shell [7]triangulene quantum ring molecule on Au(111) through surface-assisted cyclodehydrogenation of a rationally designed kekulene derivative. Bond-resolved scanning tunneling microscopy (BR-STM) and dI/dV mapping revealed the molecular structure and edge-localized electronic states of [7]TQR, confirming its retention of an open-shell septuple ground state on Au(111). This work demonstrates a new approach for designing high-spin graphene quantum rings for future quantum devices.
Article
Quantum Science & Technology
P. Bauman Nicholas, Jaroslav Chladek, Libor Veis, Jiri Pittner, Kowalski Karol
Summary: This paper discusses the utilization of VQE and GUCC formalism for diagonalization of Hamiltonians in active spaces, considering effective Hamiltonians defined by downfolding virtual orbitals and freezing core orbitals. Various solvers are considered to identify solutions of the GUCC equations, with benchmark systems N-2, H2O, and C2H4 illustrating the performance of the combined framework.
QUANTUM SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Benjamin Mallada, Bruno de la Torre, Jesus Mendieta-Moreno, Dana Nachtigallova, Adam Matej, Mikulas Matousek, Pingo Mutombo, Jiri Brabec, Libor Veis, Timothee Cadart, Martin Kotora, Pavel Jelinek
Summary: This study presents a novel route using on-surface chemistry to synthesize nonalternant polycyclic aromatic hydrocarbons containing up to four distinct kinds of non-benzenoid rings. The surface-induced mechanical constraints and peculiar ring current play a decisive role in forming the energetically unfavorable products. The research offers a new approach for synthesizing novel hydrocarbons with internal stress driven by the surface, not achievable by traditional organic chemistry methods in solution.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Pavel Beran, Mikulas Matousek, Michal Hapka, Katarzyna Pernal, Libor Veis
Summary: A new approach combining DMRG and AC technique has been proposed in this study to improve the accuracy of electronic structure calculations for strongly correlated molecules. Encouraging results on typical candidates for DMRG computations have been reported.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Pavlo Golub, Andrej Antalik, Libor Veis, Jiri Brabec
Summary: The article proposes a neural network-based approach for automatic selection of active spaces, focusing on transition metal systems. The machine learning models show reasonable accuracy in predicting active space orbitals and demonstrate transferability onto out-of-the-model systems. Additionally, the correctness of automatically selected active spaces is validated on a Fe(II)-porphyrin model.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Carlos Mejuto-Zaera, Demeter Tzeli, David Williams-Young, Norm M. Tubman, Mikulas Matousek, Jiri Brabec, Libor Veis, Sotiris S. Xantheas, Wibe A. de Jong
Summary: Iron-sulfur clusters are important functional motifs in biological catalytic centers, capable of performing important chemical transformations at ambient conditions. The electronic structure of these clusters is complex and sensitive to geometric changes, requiring large active space calculations to reveal their properties.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Daria Drwal, Pavel Beran, Micha Hapka, Marcin Modrzejewski, Adam Sokol, Libor Veis, Katarzyna Pernal
Summary: In this work, a new approach based on adiabatic connection is proposed to accurately describe the electronic structure, especially for systems with strong electron correlation. It is more efficient than existing ab initio multireference dynamic correlation methods.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Editorial Material
Chemistry, Multidisciplinary
Libor Veis
Summary: This article discusses recent progress in numerically studying the performance of ASP on strongly correlated molecules and presents several approaches to improve the quality of prepared ground state wave functions.
COMMUNICATIONS CHEMISTRY
(2022)
Article
Chemistry, Physical
Mikulas Matousek, Michal Hapka, Libor Veis, Katarzyna Pernal
Summary: A multiconfigurational adiabatic connection (AC) formalism is an attractive approach to compute the dynamic correlation within DMRG models. The study investigates the effect of removing the fixed-RDM approximation in AC and finds that lifting this approximation is a viable way toward improving the accuracy of existing AC approximations.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Pavel Beran, Katarzyna Pernal, Fabijan Pavosevic, Libor Veis
Summary: The density matrix renormalization group (DMRG) method is an efficient and accurate computational method for treating strong correlation in large active spaces. However, its application on larger molecules is limited by computational scaling and the treatment of missing dynamical electron correlation. In this work, we present a first step towards combining DMRG with density functional theory (DFT) through projection-based wave function (WF)-in-DFT embedding. On proof-of-concept molecular examples, we demonstrate that the developed DMRG-in-DFT approach accurately describes molecules with strongly correlated fragments.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Daria Drwal, Mikulas Matousek, Pavlo Golub, Aleksandra Tucholska, Michal Hapka, Jiri Brabec, Libor Veis, Katarzyna Pernal
Summary: The new generation of proposed light-emitting molecules for OLEDs with a negative ST gap has attracted research interest. Spin polarization plays a role in the inversion mechanism of the ST gap. A descriptor for screening candidate molecules with negative ST gaps is proposed. Numerical results show that the effect of spin polarization decreases linearly with increasing HOMO-LUMO exchange integral.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Materials Science, Multidisciplinary
C. Krumnow, L. Veis, J. Eisert, Oe. Legeza
Summary: The study explores the use of matrix-product states in two-dimensional fermionic models, showing significantly higher accuracy levels compared to direct embeddings into one-dimensional systems. By utilizing fermionic mode transformations and overcoming the prejudice of local embeddings in one dimension, the method captures the natural correlation structure more accurately.
