Article
Chemistry, Physical
Maria-Andreea Filip, Alex J. W. Thom
Summary: The development of multireference coupled cluster (MRCC) techniques in electronic structure theory has been challenging due to the complexity in expressing a multiconfigurational wavefunction within the single-reference coupled cluster framework. The multireference-coupled cluster Monte Carlo (mrCCMC) technique, based on the Monte Carlo approach, offers a simpler alternative but needs improvement in accuracy and computational cost. This paper explores incorporating ideas from conventional MRCC to the mrCCMC framework, resulting in methods with increased relaxation of the reference space and a better understanding of solutions to the mrCCMC equations.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
A. Waigum, J. A. Black, A. Kohn
Summary: A generalization of the hybrid scheme for multireference methods by Saitow and Yanai is presented, which constructs hybrid methods by defining internal and external excitation spaces and evaluating them at different levels of theory. New hybrids are derived and benchmarked, showing improvements in computational complexity and numerical accuracy compared to their non-hybrid parent method. The new separation of excitation space combining singles and doubles excitations into the external space is also tested and found effective.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Harrison Tuckman, Eric Neuscamman
Summary: We propose an excited-state-specific coupled-cluster approach that optimizes both molecular orbitals and cluster amplitudes for an individual excited state. This method allows the introduction of correlation effects on top of an excited-state mean field starting point. Preliminary tests demonstrate that, with N 5 cost perturbative corrections for important terms, the approach can outperform excited-state-specific second-order perturbation theory in valence, charge transfer, and Rydberg states.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Marvin H. Lechner, Robert Izsak, Marcel Nooijen, Frank Neese
Summary: The variant of the MR-EOMCC method introduces estimated amplitudes from perturbation theory, maintaining many-body formalism and state-universal properties with reduced computational costs. Performance evaluation against reference data on various test sets shows accuracy on par with multireference perturbation theories, especially useful in multistate situations where high precision is not required.
Article
Chemistry, Physical
Elisabeth Keller, Theodoros Tsatsoulis, Karsten Reuter, Johannes T. Margraf
Summary: This paper explores how regularization can ameliorate the issues of second-order Moller-Plesset perturbation theory (MP2) for metallic, polarizable, and strongly correlated periodic systems. Two regularized second-order methods are applied to various systems, leading to consistent improvements over the MP2 baseline with different regularizers found to be suitable for different systems.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Jan-Niklas Boyn, David A. Mazziotti
Summary: Accurately resolving the chemical properties of strongly correlated systems requires the use of electronic structure theories that account for both multi-reference and dynamic correlation effects. This study explores the use of density functional theory as a cost-effective alternative to generate reference orbitals for post-configuration-interaction dynamic correlation calculations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Junzi Liu, Lan Cheng
Summary: The article reviews the development of relativistic coupled-cluster and equation-of-motion coupled-cluster methods, focusing on recent efforts to improve computational efficiency and extend the methods to molecules containing heavy elements. Future directions for the development of these methods are also discussed.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Hector H. Corzo, Andreas Erbs Hillers-Bendtsen, Ashleigh Barnes, Abdulrahman Y. Zamani, Filip Pawlowski, Jeppe Olsen, Poul Jorgensen, Kurt V. Mikkelsen, Dmytro Bykov
Summary: This study addresses the computational challenges of investigating complex chemical systems using ab-initio methodologies. The researchers introduce the Divide-Expand-Consolidate (DEC) approach, which is a linear-scaling, massively parallel framework, as a viable solution for coupled cluster (CC) theory. They also present the cluster perturbation theory to mitigate the inherent limitations of DEC. Furthermore, they propose the CPS (D-3) model, derived from a CC singles parent and a doubles auxiliary excitation space, for efficient computation of excitation energies in large molecular systems. Overall, this study provides new algorithms and frameworks that can significantly improve the calculation of molecular properties.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Physical
Thomas Schraivogel, Aron J. Cohen, Ali Alavi, Daniel Kats
Summary: In this study, transcorrelated coupled cluster and distinguishable cluster methods are introduced, where the Hamiltonian is transformed using a Jastrow factor in first quantization leading to improved basis set convergence and accuracy. The coupled cluster with singles and doubles equations on the transformed Hamiltonian shows superior performance compared to conventional and explicitly correlated methods. Approaches for approximating three-body integrals are also suggested and evaluated.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Soumi Haldar, Abhishek Mitra, Matthew R. Hermes, Laura Gagliardi
Summary: In this study, we investigated the negatively charged nitrogen-vacancy center in diamond using periodic density matrix embedding theory (pDMET). To accurately describe the strongly correlated excited states of the system, we utilized the complete active space self-consistent field (CASSCF) method followed by n-electron valence state second-order perturbation theory (NEVPT2) as the impurity solver. By extrapolating the excitation energies to the nonembedding limit using linear regression, we obtained the first triplet-triplet excitation energy of 2.31 eV and the singlet-singlet transition energy of 1.02 eV, both in agreement with experimental observations. This is the first application of pDMET to a charged periodic system and the first investigation of the NV- defect using NEVPT2 for periodic supercell models.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Stuart Shepard, Ramon L. Panades-Barrueta, Saverio Moroni, Anthony Scemama, Claudia Filippi
Summary: This study demonstrates the accuracy of recently developed quantum Monte Carlo methods in calculating vertical transition energies for both single and double excitations. By studying medium-sized molecules, the researchers find that these methods exhibit good agreement with high-level coupled-cluster calculations and provide accurate predictions for excitation energies in challenging systems where reference values are lacking.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Ilia M. Mazin, Alexander Yu Sokolov
Summary: This study presents a new implementation and benchmark of approximations in multireference algebraic diagrammatic construction theory for simulations of neutral electronic excitations and UV/vis spectra of strongly correlated molecular systems. The results demonstrate that the proposed MR-ADC methods outperform third-order single-reference ADC approximation for weakly correlated electronic states and are competitive with equation-of-motion coupled cluster theory results. For states with multireference character, the performance of the MR-ADC methods is similar to that of N-electron valence perturbation theory.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Joshua A. Black, Alexander Waigum, Robert G. Adam, K. R. Shamasundar, Andreas Koehn
Summary: This article presents a new implementation of the internally contracted multireference coupled-cluster with singles and doubles (icMRCCSD) method. The new code utilizes an efficient tensor contraction kernel and avoids full four-external integral transformations, resulting in an expanded applicability of icMRCCSD. The implementation currently focuses on the simple case of two active electrons in two orbitals and supports the computation of spin-adapted doublet and triplet coupled-cluster wavefunctions.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Avijit Shee, Chia-Nan Yeh, Dominika Zgid
Summary: Within the framework of self-energy embedding theory (SEET), we have studied the application of coupled cluster Green's function (GFCC) method in two different contexts. Our research sheds light on the strengths and weaknesses of GFCC as an impurity solver and reveals that increasing the rank of the solver is necessary to achieve reliable accuracy when dealing with larger impurity problems. We have also shown that natural orbitals from weakly correlated perturbative methods are better suited for determining the total energy of the system compared to symmetrized atomic orbitals (SAO).
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Astronomy & Astrophysics
Qian-Qian Bai, Chun-Xuan Wang, Yang Xiao, Jun-Xu Lu, Li-Sheng Geng
Summary: In this work, the relativistic chiral nuclear force is used to simulate the nucleon-nucleon scattering amplitude in lattice simulations. The study focuses on the S-3(1)-D-3(1) coupled channel for a pion mass of 469 MeV. The results show that the relativistic chiral nuclear force provides a good description of the scattering amplitude up to certain energy ranges, but deteriorates at higher orders. The study also highlights discrepancies between the results and lattice QCD predictions.
Article
Chemistry, Physical
Nan He, Francesco A. Evangelista
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Nicholas H. Stair, Renke Huang, Francesco A. Evangelista
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2020)
Article
Chemistry, Physical
Daniel G. A. Smith, Lori A. Burns, Andrew C. Simmonett, Robert M. Parrish, Matthew C. Schieber, Raimondas Galvelis, Peter Kraus, Holger Kruse, Roberto Di Remigio, Asem Alenaizan, Andrew M. James, Susi Lehtola, Jonathon P. Misiewicz, Maximilian Scheurer, Robert A. Shaw, Jeffrey B. Schriber, Yi Xie, Zachary L. Glick, Dominic A. Sirianni, Joseph Senan O'Brien, Jonathan M. Waldrop, Ashutosh Kumar, Edward G. Hohenstein, Benjamin P. Pritchard, Bernard R. Brooks, Henry F. Schaefer, Alexander Yu. Sokolov, Konrad Patkowski, A. Eugene DePrince, Ugur Bozkaya, Rollin A. King, Francesco A. Evangelista, Justin M. Turney, T. Daniel Crawford, C. David Sherrill
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Nanoscience & Nanotechnology
Zihao Xu, Zhiyuan Huang, Chenyang Li, Tingting Huang, Francesco A. Evangelista, Ming L. Tang, Tianquan Lian
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Chemistry, Physical
Chenyang Li, Francesco A. Evangelista
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Nicholas H. Stair, Francesco A. Evangelista
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Quantum Science & Technology
Armin Khamoshi, Francesco A. Evangelista, Gustavo E. Scuseria
Summary: Recent studies have shown that the antisymmetrized geminal power (AGP) wavefunction can be an excellent starting point for describing systems with strong pairing correlations. Efficient implementation of AGP on a quantum computer was achieved with highly accurate ground state energies benchmarked on the pairing Hamiltonian.
QUANTUM SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Physical
Chenyang Li, Francesco A. Evangelista
Summary: This study presents a spin-free formulation of the multireference driven similarity renormalization group based on ensemble normal ordering, which is used to compute constants of diatomic molecules and spin splittings of transition-metal complexes, demonstrating that third-order perturbative corrections are essential for achieving reasonably converged energetics. The results suggest good agreement with local CC theory, highlighting the importance of spin-free quantities in accurately predicting molecular properties.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Meng Huang, Chenyang Li, Francesco A. Evangelista
Summary: This study extends the MR-DSRG method to compute core-excited states, achieving satisfactory results when combined with GASSCF treatment. After testing on 16 core-excited states, all theoretical models show excellent agreement with experimental data.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Shuhe Wang, Chenyang Li, Francesco A. Evangelista
Summary: The study derives analytic energy gradients of DSRG MRPT2 using Lagrange multipliers, and optimizes the geometry of p-benzyne states with promising results. An approximate DSRG-MRPT2 method shows negligible errors in geometry optimizations, making it a low-cost approach.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Quantum Science & Technology
Armin Khamoshi, Guo P. Chen, Francesco A. Evangelista, Gustavo E. Scuseria
Summary: The paper introduces a unitary coupled cluster method based on AGP for electronic structure calculations and quantum computing. The method is demonstrated for the Fermi-Hubbard Hamiltonian and post-selection is explored as an efficient state preparation step. The results show that this method provides a less expensive alternative for restoring particle number symmetry.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Mitchell E. Lahm, Nathaniel L. Kitzmiller, Henry F. Mull, Wesley D. Allen, Henry F. Schaefer
Summary: The Concordant Mode Approach (CMA) is a hierarchical structure for quantum chemical computations of harmonic vibrational frequencies, increasing system size and theory level. CMA utilizes transferrable normal modes computed at a lower level of theory as a basis for higher level calculations. Comprehensive tests on over 120 molecules have established the accuracy of CMA methods.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Shuhang Li, Jonathon P. Misiewicz, Francesco A. Evangelista
Summary: This work examines the effect of various cumulant truncation schemes on the accuracy of the driven similarity renormalization group second-order multireference perturbation theory. The results show that these cumulant truncations can reduce both relative and absolute errors and also decrease the required memory space.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Pascal Vermeeren, Marco Dalla Tiezza, Mark E. Wolf, Mitchell E. Lahm, Wesley D. Allen, Henry F. Schaefer, Trevor A. Hamlin, F. Matthias Bickelhaupt
Summary: This study performed hierarchical, convergent ab initio benchmark computations to analyze the performance of density functional theory (DFT) in five pericyclic reactions. It used focal point analyses (FPA) to evaluate 60 density functionals and found that the meta-hybrid M06-2X functional provided the best overall performance. The study also demonstrated that accurate and efficient meta-hybrid or double-hybrid DFT potential energy surfaces can be obtained based on geometries from the computationally efficient and robust BP86/DZP level.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Quantum Science & Technology
Nicholas H. Stair, Francesco A. Evangelista
Summary: The study introduces a new hybrid quantum-classical algorithm called PQE for optimizing UCC wave functions, which outperforms variational quantum algorithms. Residuals can be evaluated by measuring two energy expectation values, and a selected variant SPQE offers an adaptive ansatz as an alternative to gradient-based selection procedures.
Article
Chemistry, Physical
Sergey Yu. Ketkov, Sheng-Yuan Tzeng, Elena A. Rychagova, Anton N. Lukoyanov, Wen-Bih Tzeng
Summary: Metallocenes, including methylcobaltocene, play important roles in various fields of chemistry. The ionization energy and vibrational structure of (Cp ')(Cp)Co can be influenced by introducing methyl substituents. The mass-analyzed threshold ionization spectrum and DFT calculations provide accurate information about the properties and transformations of (Cp ')(Cp)Co.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Review
Chemistry, Physical
Qifeng Mu, Jian Hu
Summary: Polymer mechanochemistry has experienced a renaissance due to the rapid development of mechanophores and principles governing mechanochemical transduction or material strengthening. It has not only provided fundamental guidelines for converting mechanical energy into chemical output, but also found applications in engineering and smart devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Da Hye Yang, Francesco Ricci, Fredrik L. Nordstrom, Na Li
Summary: Through systematic evaluation of the oiling-out behavior of procaine, we identified both stable and metastable liquid-liquid phase separation, and established phase diagrams to assist in rational selection of crystallization strategies.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Vikki Anand Varma, Simmie Jaglan, Mohd Yasir Khan, Sujin B. Babu
Summary: Designing engineering structures like nanocages, shells, and containers through self-assembly of colloids is a challenging problem. This work proposes a simple model for the subunit, which leads to the formation of monodispersed spherical cages or containers. The model with only one control parameter can be used to design cages with the desired radius.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Hainan Jiang, Yaolong He, Xiaolin Li, Zhiyao Jin, Huijie Yu, Dawei Li
Summary: The cycling lifespan and coulombic efficiency of lithium-ion batteries are crucial for high C-rate applications. The Li-ion concentration plays a crucial role in determining the mechanical integrity and structural stability of electrodes. This study focuses on graphite as the working electrode and establishes an experimental system to investigate the mechanical properties of composite graphite electrode at different C-rates. Considering the effect of Li-ion concentration in stress analysis is found to be significant.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Zhiye Wang, Yunchuan Li, Mingjun Sun
Summary: This study investigates the influence of intramolecular pi-pi interactions on the electronic transport capabilities of molecules. By designing and analyzing three pi-conjugated molecules, the researchers observe that different pi-conjugated structures have varying effects on electron transport. The findings provide a theoretical foundation for designing single-molecule electronic devices with multiple electron channels based on intramolecular pi-pi interactions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Yuandong Xu, Haoyang Feng, Chaoyang Dong, Yuqing Yang, Meng Zhou, Yajun Wei, Hui Guo, Yaqing Wei, Jishan Su, Yingying Ben, Xia Zhang
Summary: Hollow MoS2 cubes and spheres were successfully synthesized using a one-step hydrothermal method with the hard template method. The hollow MoS2 cubes exhibited higher specific capacitance and energy density compared to the hollow MoS2 spheres. The symmetrical supercapacitors assembled with these hollow structures showed good performance and high capacity retention after multiple cycles. These findings suggest that controlling the pore structure and surface characteristics of MoS2 is crucial for enhancing its electrochemical properties.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Ainhoa Oliden-Sanchez, Rebeca Sola-Llano, Joaquin Perez-Pariente, Luis Gomez-Hortiguela, Virginia Martinez-Martinez
Summary: The combination of photoactive molecules and inorganic structures is important for the development of advanced materials in optics. In this study, bulky dyes were successfully encapsulated in a zeolitic framework, resulting in emission throughout the visible spectrum.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Miaomiao Zhang, Cunyuan Pei, Qiqi Xiang, Lintao Liu, Zhongxu Dai, Huijuan Ma, Shibing Ni
Summary: The design of a solid electrolyte interphase (SEI) plays a crucial role in improving the electrochemical performance of anode materials. In this study, lithium difluoro(oxalate)borate (LiDFOB) is used as an electrolyte additive to form a protective SEI film on Li3VO4 (LVO) anodes. The addition of LiDFOB results in a dense, uniform, stable, and LiF-richer SEI, which enhances the Li-ion storage kinetics. The generated SEI also prevents further decomposition of the electrolyte and maintains the morphology of LVO anodes during charge/discharge processes. This work demonstrates the effectiveness of LiDFOB as a multi-functional additive for LiPF6 electrolytes and provides insights into SEI construction for high-performance LVO anodes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
B. V. Andryushechkin, T. V. Pavlova, V. M. Shevlyuga
Summary: The atomic structure of the Ag(111)-p(4 x 4)-O phase was reexamined and two phases with the same periodicity were discovered. It was demonstrated that the accepted Ag6 model is incompatible with high-resolution oxygen-sensitive STM images.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
S. L. Romo-Avila, D. Marquez-Ruiz, R. A. Guirado-Lopez
Summary: In this study, we used density functional theory (DFT) calculations to investigate the interaction between model graphene oxide (GO) nanostructures and chlorine monoxide ClO. We aimed to understand the role of this highly oxidizing species in breaking C-C bonds and forming significant holes on GO sheets. Our results showed that C-C bonds in a single graphene oxide sheet can be broken through a simple mechanism involving the dissociation of two chemically attached ClO molecules. The formation of carbonyl groups and holes on the GO surface was also observed. This study provides important insights into the degradation of carbon nanotubes and the stability of GO during the myeloperoxidase (MPO) catalytic cycle.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Alberto Garcia-Fernandez, Birgit Kammlander, Stefania Riva, Hakan Rensmo, Ute B. Cappel
Summary: In this study, the X-ray stability of five different lead halide perovskite compositions (MAPbI3, MAPbCl3, MAPbBr3, FAPbBr3, CsPbBr3) was investigated using photoelectron spectroscopy. Different degradation mechanisms and resistance to X-ray were observed depending on the crystal composition. Overall, perovskite compositions based on the MA+ cation were found to be less stable than those based on FA+ or Cs+. Metallic lead formation was most easily observed in the chloride perovskite, followed by bromide, and very little in MAPbI3. Multiple degradation processes were identified for the bromide compositions, including ion migration, formation of volatile and solid products, as well as metallic lead. CsBr was formed as a solid degradation product on the surface of CsPbBr3.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Timofei Rostilov, Vadim Ziborov, Alexander Dolgoborodov, Mikhail Kuskov
Summary: The shock-loading behavior of nanomaterials is investigated in this study. It is found that shock compaction waves exhibit a distinct two-step structure, with the formation of faster precursor waves that travel ahead of the main compaction waves. The complexity of the shock Hugoniot curve of the tested nanomaterial is described, and the effect of initial porosity on the compressed states is demonstrated.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Sergey S. Nikitin, Alexander D. Koryakov, Elizaveta A. Antipinskaya, Alexey A. Markov, Mikhail V. Patrakeev
Summary: The stability of La1/3Sr2/3Fe1-xMnxO3-delta, a perovskite-type oxide, under reducing conditions is dependent on the manganese content. Increasing the manganese content leads to a decrease in stability. The behavior of iron and manganese in the oxide shows distinct differences, which can be attributed to the difference in the enthalpy of oxidation reactions. Additionally, the change in the La/Sr ratio affects the concentration of iron and manganese ions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
Article
Chemistry, Physical
Mosayeb Naseri, Shirin Amirian, Mehrdad Faraji, Mohammad Abdur Rashid, Maicon Pierre Lourenco, Venkataraman Thangadurai, D. R. Salahub
Summary: Inspired by the successful transfer of freestanding ultrathin films of SrTiO3 and BiFeO3, this study assessed the structural stability and investigated the electronic, optical, and thermoelectric properties of a group of two-dimensional perovskite-type materials called perovskenes. The findings revealed that these materials are wide bandgap semiconductors with potential application in UV shielding. Moreover, they exhibit better electrical and thermal conductivity at high temperatures, enabling efficient power generation in thermoelectric devices.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2024)
