Article
Chemistry, Physical
Ignacio Ema, Guillermo Ramirez, Rafael Lopez, Jesus San Fabian, Jose M. Garcia de la Vega
Summary: This study investigates weakly bound neon dimer, trimer and tetramers using various basis sets. The study examines their binding energies and structural properties. The results show that the SIGMA-s basis sets perform well in this study and can be applied to the study of larger weakly bound systems of other atoms. Difficulties in obtaining accurate results are assessed through computations of total, atomization, and correlation energies, as well as equilibrium distances using different basis sets of increasing size. Extrapolations are proposed to predict stabilization energies and compared with previously published data.
Article
Chemistry, Physical
Vijay Gopal Chilkuri, Frank Neese
Summary: This work focuses on benchmark calculations based on the ICE program and compares the performance of different types of many-particle basis functions. By analyzing the number of wavefunction parameters, energy error, and the best way to extrapolate ICE energies towards FCI results, the study explores the implications of the three many-particle representations in selected CI implementations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Multidisciplinary
R. Aravindhan, Jianping Hu, M. Ummal Momeen
Summary: The polarity of solvents has a significant impact on the optical absorption and electronic structure of 1-iodoadamantane, resulting in solvatochromic shifts. The absorption shift for sigma to sigma* and n to sigma* electronic transitions is more pronounced in polar solvents.
Article
Chemistry, Physical
Jiaxin Chen, Chengyuan Zhang, Yanling Lu, Hainan Wang, Yongqing Li
Summary: A large number of ab initio energy points were calculated using the aug-cc-pV(Q,5)Z basis sets and extrapolated to the complete basis set limit. An exact potential energy surface of the ground-state BH2+ was obtained, and a switching function was developed to model transitions. The topographic features of the new global potential energy surface were discussed in detail, and integral cross sections of a reaction were calculated using the quasi-classical trajectory method.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Andreas Irmler, Alejandro Gallo, Andreas Grueneis
Summary: A basis set correction scheme is proposed for the coupled-cluster method, utilizing frozen natural orbitals and decomposed contributions to electronic correlation energy. By introducing a simple approximation method, the basis set incompleteness error is effectively reduced, demonstrating good performance in calculations of atoms and molecules.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
F. Zahariev, M. S. Gordon
Summary: The previously developed combined Quantum Monte Carlo-Effective Fragment Molecular Orbital (QMC-EFMO) method has been extended to systems where the fragmentation process cuts across covalent molecular bonds. The extended QMC-EFMO capability was demonstrated on several model systems with good agreement between full QMC and QMC-EFMO for both the correlation energy and energy differences. The differences were within 2 kcal mol(-1) and 1 kcal mol(-1) respectively.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Khanh Ngoc Pham, Marcin Modrzejewski, Jiri Klimes
Summary: In this study, the accuracy of MP2 and non-self-consistent RPA methods is tested using benchmark data generated from the coupled-cluster method. It is found that both methods poorly describe the non-additive many-body interactions in closely packed clusters.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Wataru Sotoyama
Summary: The Delta SCF method demonstrated high accuracy in simulating the excited states and photophysical properties of TADF molecules, particularly in calculating S-1 and T-1 excitation energies, as well as the S-1-T-1 gap.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Multidisciplinary
Samantha G. Le Roux, Bernard Dippenaar, Thalia Carstens, Catharine Esterhuysen, Delia A. Haynes
Summary: Crystals of the elusive alpha-polymorph of the dithiadiazolyl radical p-NCC6F4CNSSN center dot (1) have been isolated from co-sublimations with a second radical 2,6-C6H4F2CNSSN center dot (2). The co-sublimation of 1 and 2 also allows control of the crystal morphology of the beta-polymorph of 1, resulting in blocks instead of needles. Analysis of intermolecular interaction strengths in both polymorphs provides insight into a proposed mechanism for polymorph control.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Inorganic & Nuclear
Nina Huittinen, Isabelle Jessat, Florent Real, Valerie Vallet, Sebastian Starke, Manuel Eibl, Norbert Jordan
Summary: In this study, the coordination chemistry of Cm(III) with aqueous phosphates was investigated using laser-induced luminescence spectroscopy and ab initio simulations. The formation of Cm(H2PO4)(2)(+) was confirmed for the first time, along with deriving complexation constants and thermodynamic parameters. The results showed a temperature-dependent coordination change for the Cm(III)-phosphate complexes, with different coordination numbers observed at different temperatures.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Michael Glasbrenner, Sigurd Vogler, Christian Ochsenfeld
Summary: A method using second-order Moller-Plesset perturbation theory for computing NMR shieldings efficiently derives equations from Laplace-transformed atomic orbitals, minimizing the number of equations to be solved with the Z-vector approach. The method also utilizes the resolution-of-the-identity approximation and Cholesky decomposition of pseudo-density matrices, as well as exploiting sparsity in three-center integrals with sparse linear algebra approaches. Test calculations show small deviations from NMR shifts obtained with canonical MP2, and the method's performance is illustrated in calculations on DNA strands and glycine chains.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Eleanor K. Ashworth, Mark H. Stockett, Christina Kjaer, Philip C. Bulman Page, Stephen R. Meech, Steen Brondsted Nielsen, James N. Bull
Summary: This study uses photodissociation action spectroscopy to investigate the absorption spectra of synthetic GFP and rKFP chromophores, and uses electronic structure calculations and energy decomposition analysis to study the gas-phase structures and complex cohesion forces. The results reveal that the betaine molecule mainly interacts with the phenoxide deprotonation site through electrostatic forces. In contrast, a point-charge model based on common electron density population analysis schemes is unable to fully explain the betaine-induced spectral shift.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Pedro Salvador, Istvan Mayer
Summary: The study introduces a new method based on the chemical Hamiltonian approach, which reduces basis set superposition error. Comparing with previous methods, it shows a significant simplification, but performs poorly with the aug-cc-pVDZ basis set.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2022)
Article
Mathematics, Applied
Wieslawa Kaczor, Tadeusz Kuczumow, Simeon Reich, Mariola Walczyk
Summary: We demonstrate that every infinite-dimensional reflexive Banach space (X, 11.11(X)) possesses an equivalent norm 11.11(X,0) such that (X, 11.11X,0) is LUR and encompasses a diametrically complete set with an empty interior. Moreover, we establish that, following a suitable equivalent renorming, the Banach space C([0, 1], R) accommodates a constant width set with an empty interior.
RESULTS IN MATHEMATICS
(2023)
Article
Chemistry, Physical
Matthieu Wolf, Didier Begue, Germain Salvato Vallverdu
Summary: This article presents a new reactive potential in the ReaxFF formalism, named CHONCl-2022_weak, for studying organochloride compounds. The study demonstrates that the new force field accurately describes the structure and reactivity of the compounds and successfully investigates the reaction pathways of chlorobenzene in atmospheric conditions and aqueous solutions.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Tomas Bucko, Monika Gesvandtnerova, Dario Rocca
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2020)
Article
Chemistry, Physical
T. Ayadi, L. Debbichi, M. Badawi, M. Said, D. Rocca, S. Lebegue
Summary: This study investigated the electronic properties of the bidimensional ferroelectric heterostructure In2Se3/Bi2Se3 using ab initio calculations. The material was found to have varying bandgap types and band alignments depending on the direction of the polarization vector, with the potential for tuning these properties with an external electric field. This suggests promising applications in electronic and optoelectronic systems.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Monika Gesvandtnerova, Dario Rocca, Tomas Bucko
Summary: In this study, a detailed ab initio investigation of the carbonylation reaction of methoxy groups in zeolite mordenite was conducted using full molecular dynamics simulations. The results indicate a preference for the reaction in the side pocket, which was further supported by calculations using various density functional theory approximations with or without dispersion corrections. This research also introduced a new approach combining thermodynamic perturbation theory with machine learning to reduce computational costs.
JOURNAL OF CATALYSIS
(2021)
Article
Physics, Multidisciplinary
Mauricio Chagas da Silva, Michael Lorke, Balint Aradi, Meisam Farzalipour Tabriz, Thomas Frauenheim, Angel Rubio, Dario Rocca, Peter Deak
Summary: Super cell models are commonly employed to calculate the electronic structure of local deviations from ideal periodicity. A correction scheme for artificially repeated charges is proposed and successfully tested for bulk and slab calculations, especially important in preventing spurious states in the vacuum.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Condensed Matter
M. Barhoumi, D. Rocca, M. Said, S. Lebegue
Summary: Elastic constants play a central role in regulating the thermo-mechanical and anisotropic response of materials. In this study, diamond and silicon's elastic constants were obtained using density functional theory and the random phase approximation, showing excellent agreement with experimental data. The mechanical properties of these materials were studied, and 3D and 2D plots were visualized for Young's modulus, Poisson's ratio, and others.
SOLID STATE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Bastien Casier, Mauricio Chagas da Silva, Michael Badawi, Fabien Pascale, Tomas Bucko, Sebastien Lebegue, Dario Rocca
Summary: The combination of electronic structure and machine learning techniques is a powerful tool for predicting chemical and physical properties. A novel descriptor based on molecular graphs has been proposed in this work, showing improved accuracy in energy predictions through the hybridization of two kernel functions.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2021)
Article
Physics, Applied
Koussai Lazaar, Saber Gueddida, Ali Abboud, Moncef Said, Dario Rocca, Sebastien Lebegue
Summary: The properties of these two-dimensional quaternary compounds are suitable for water splitting, their heterostructures facilitate efficient electron-hole separation, and graphene heterostructures with these compounds exhibit a p-type nature.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Alekos Segalina, Sebastien Lebegue, Dario Rocca, Simone Piccinin, Mariachiara Pastore
Summary: Level alignment plays a crucial role in dye-sensitized photoelectrodes. Accurately predicting the interface structure through first-principles calculations is crucial for optimizing the device. By combining experimental and computational methods, this study successfully describes the structure and level alignment of the C343-sensitized NiO surface in water.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Basile Herzog, Mauricio Chagas da Silva, Bastien Casier, Michael Badawi, Fabien Pascale, Tomas Bucko, Sebastien Lebegue, Dario Rocca
Summary: Machine learning thermodynamic perturbation theory (MLPT) is a promising approach for computing finite temperature properties, especially when comparing different levels of theory or using expensive computational methods. This study evaluates the accuracy of MLPT for calculating ensemble total energies and enthalpies of adsorption, and proposes a machine-learning-based Monte Carlo resampling method to recover target-level results within chemical accuracy.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Federico Coppola, Martina Nucci, Marco Marazzi, Dario Rocca, Mariachiara Pastore
Summary: In this study, we investigated the photophysics and photochemistry of a molecular switch for solar energy storage and release. We characterized the valence and Rydberg states of norbornadiene (NBD) and quadricyclane (QC) using CASPT2//CASSCF theory, and found good agreement with experimental results. We studied the NBD <-> QC thermal and photochemical valence isomerization reactions and identified low energy crossing points between excited states. The doubly excited valence state was found to play a crucial role in the photoreactivity of both NBD and QC.
Article
Chemistry, Multidisciplinary
Dong Seob Kim, Di Huang, Chunhao Guo, Kejun Li, Dario Rocca, Frank Y. Gao, Jeongheon Choe, David Lujan, Ting-Hsuan Wu, Kung-Hsuan Lin, Edoardo Baldini, Li Yang, Shivani Sharma, Raju Kalaivanan, Raman Sankar, Shang-Fan Lee, Yuan Ping, Xiaoqin Li
Summary: A long-standing pursuit in materials science is to identify suitable magnetic semiconductors for integrated information storage, processing, and transfer. Van der Waals magnets have brought forth new material candidates for this purpose. Recently, sharp exciton resonances in antiferromagnet NiPS3 have been reported to correlate with magnetic order, that is, the exciton photoluminescence intensity diminishes above the Neel temperature. Here, it is found that the polarization of maximal exciton emission rotates locally, revealing three possible spin chain directions. This study shows that anisotropic exciton photoluminescence can be used to read out local spin chain directions in antiferromagnets and realize multi-functional devices via spin-photon transduction.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Basile Herzog, Bastien Casier, Sebastin Lebegue, Dario Rocca
Summary: The configuration interaction approach is a powerful method for solving the Schrödinger equation in realistic molecules and materials, but it has a scalability issue that limits its practical use. In this study, we propose a machine learning approach to selectively generate important configurations, which leads to faster convergence to chemical accuracy compared to random sampling or Monte Carlo configuration interaction method. This work opens up new possibilities for using generative models to solve electronic structure problems.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Bin Liu, Dario Rocca, He Yan, Ding Pan
Summary: It has been found that the sulfur-nitrogen noncovalent interaction may reduce the band gaps of polymers and enhance charge transfer more significantly than other noncovalent interactions, a discovery consistent with experimental data. This interaction may further influence the electronic structure of coplanar conjugated polymers beyond just improving molecular planarity, suggesting a new mechanism for manipulating the electronic properties of polymers for high-performance solar cells.
Article
Chemistry, Physical
Minho Kim, Tim Gould, Ekaterina I. Izgorodina, Dario Rocca, Sebastien Lebegue
Summary: This study tests various dispersion corrected versatile Generalized Gradient Approximation (GGA) and meta-GGA functionals for predicting interactions of ionic liquids, finding that most can predict energies accurately. Additionally, it shows that PBE calculations and GTO methods have negligible differences in evaluating ionic liquids. Furthermore, explicit van der Waals density functionals show higher success rates compared to traditional dispersion models, indicating a need for improvements in low-cost dispersion correction models for ions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Fernanda C. Bononi, Zekun Chen, Dario Rocca, Oliviero Andreussi, Ted Hullar, Cort Anastasio, Davide Donadio
JOURNAL OF PHYSICAL CHEMISTRY A
(2020)
