Article
Chemistry, Physical
Andy Kaiser, Razan E. Daoud, Francesco Aquilante, Oliver Kuhn, Luca De Vico, Sergey I. Bokarev
Summary: We implemented the Frenkel exciton model into the OpenMolcas program package to calculate collective electronic excited states of molecular aggregates. Our protocol does not rely on diabatization schemes or supermolecule calculations, and the use of Cholesky decomposition for pair interactions improves computational efficiency. We applied our method to two test systems and compared it with the dipole approximation.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Jozsef Csoka, Mihaly Kallay
Summary: We present analytic gradients for local density fitting Hartree-Fock (HF) and hybrid Kohn-Sham (KS) density functional methods. Due to the non-variational nature of the local fitting algorithm, the method of Lagrange multipliers is used to avoid the solution of the coupled perturbed HF and KS equations. Efficient algorithms for Z-vector equations and gradient calculation are proposed, preserving the scalability and low memory requirement of the original local fitting algorithm.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Ashutosh Kumar, Ayush Asthana, Conner Masteran, Edward F. Vleev, Yu Zhang, Lukasz Cincio, Sergei Tretiak, Pavel A. Dub
Summary: This paper attempts to reduce the quantum resource requirements for molecular simulations on quantum computers while maintaining the desired accuracy. By using compact and balanced transcorrelated Hamiltonians to describe both the ground and excited states of molecular systems, and employing the VQE method and qEOM formalism, the number of required quantum gates and the deviations in excitation energies can be greatly reduced.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Jannis Erhard, Steffen Fauser, Egor Trushin, Andreas Goerling
Summary: The recently introduced sigma-functionals provide a new type of functionals for the Kohn-Sham correlation energy. They are based on the adiabatic-connection fluctuation-dissipation theorem and are computationally related to the direct random phase approximation (dRPA). However, a shortcoming of sigma-functionals is their inability to accurately describe processes involving a change in the electron number. This problem is tackled by introducing a scaling of the eigenvalues of the KS response function, resulting in scaled sigma-functionals that retain accuracy and computational efficiency.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Dirk Bakowies
Summary: ATOMIC is a thermochemistry protocol that evaluates atomization energies and enthalpies of formation using bond separation reactions. ATOMIC-2 is an improved version that increases computational efficiency, accuracy, and adds an error and uncertainty model.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Gabriel L. S. Rodrigues, Mikael Scott, Mickael G. Delcey
Summary: Multiconfigurational pair-density functional theory (MC-PDFT) is an inexpensive way to describe both strong and dynamic correlations. This study demonstrates that the previously neglected imaginary component is actually necessary to reproduce the correct physical behavior, especially in low-spin open shell systems.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Thomas Bondo Pedersen, Susi Lehtola, Ignacio Fdez Galvan, Roland Lindh
Summary: This review provides an overview of the RI/DF and CD methods in electronic structure calculations, highlighting the close relationship between these two approaches. It traces the evolution and current state of the CD method, which offers not only a numerical procedure for handling ERIs, but also highly accurate approaches for generating auxiliary basis sets for the RI/DF approximation.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2023)
Article
Chemistry, Physical
Hong-Zhou Ye, Timothy C. Berkelbach
Summary: This paper presents a strategy for constructing high-quality Gaussian basis sets suitable for periodic calculations and examines their accuracy and numerical stability. By limiting the number of primitive functions, numerical issues can be avoided and smooth convergence can be achieved.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
F. Tonolo, L. Bizzocchi, M. Melosso, F. Lique, L. Dore, V. Barone, C. Puzzarini
Summary: This study aims to provide improved scattering parameters for the HCO+ and He collisional system, validate the accuracy of the methodology used for potential well calculation, and derive pressure broadening and shift coefficients for rotational transitions of HCO+ through solving close-coupling scattering equations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
Patrick Vossnacker, Alisa Wuest, Thomas Keilhack, Carsten Muller, Simon Steinhauer, Helmut Beckers, Sivathmeehan Yogendra, Yuliya Schiesser, Rainer Weber, Marc Reimann, Robert Mueller, Martin Kaupp, Sebastian Riedel
Summary: Chloride ions have been found to be efficient catalysts for the synthesis of phosgene from carbon monoxide and elemental chlorine at room temperature and atmospheric pressure. Through control experiments, the role of [NEt3Me][Cl-3] as an active species has been highlighted. This discovery opens up the possibility of using [NEt3Me]Cl as a catalyst for phosgene production and chlorine storage.
Article
Chemistry, Physical
Niklas Thoben, Thorsten Klu''ner
Summary: This study investigates the spatial and electronic structure of the Si-terminated surface of cubic silicon carbide (3C-SiC) and its p(2x1) reconstruction using restricted and unrestricted single- and multiconfigurational calculations. The results show that the unrestricted calculations allow for stronger reconstruction, while the multiconfigurational calculations reveal the important role of the bonding and antibonding surface states and the interaction of neighboring dimers. Additionally, the excited-state calculations suggest that both the p(2x1) and p(1x1) surfaces are semiconducting.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
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, Physical
Zachary M. Sparrow, Brian G. Ernst, Paul T. Joo, Ka Un Lao, Robert A. DiStasio
Summary: NENCI-2021 presents a benchmark database of 8000 intermolecular complexes for chemical sciences, systematically sampling potential energy surfaces and close contacts, providing valuable data for testing, training, and developing various chemical simulation methods.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
M. A. Ambroise, F. Sacchetta, D. Graf, C. Ochsenfeld, A. Dreuw
Summary: A novel local approach is proposed for the quantum-chemical computation of excited states by extending the atomic-orbital formulation to the second-order algebraic diagrammatic construction scheme using Laplace transform. The CDD-DF-SOS-ADC(2) method achieves substantial reduction in computational effort by exploiting the sparsity of two-electron repulsion integrals, atomic ground-state density matrix, and atomic transition density matrix. It is shown that asymptotically linear scaling can be achieved for linear carboxylic acids, and sub-cubic scaling can be achieved for electron-dense systems with sparse transition density. The memory footprint and accuracy of the method are also explored.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Mihaly Kallay, Reka A. Horvath, Laszlo Gyevi-Nagy, Peter R. Nagy
Summary: A new method is proposed to reduce basis set incompleteness error in triple excitation corrections, which is size-consistent and easy to implement. The performance of this approach is evaluated for atomization, reaction, and interaction energies, as well as bond lengths and vibrational frequencies, showing promising results.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Medicinal
Daniel Sethio, Vasanthanathan Poongavanam, Ruisheng Xiong, Mohit Tyagi, Duc Duy Vo, Roland Lindh, Jan Kihlberg
Summary: Conformational analysis is crucial for the design of bioactive molecules, and it becomes even more challenging for macrocycles due to their unique characteristics. In this study, we simulated the conformations of five designed macrocycles and verified the results against experimental measurements. Our simulations accurately predicted the intramolecular interactions and revealed a solvent-induced conformational switch of the macrocyclic ring. This provides a foundation for the rational design of molecular chameleons that can adapt to different environments.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Chemistry, Physical
Benedicte Sverdrup Ofstad, Hakon Emil Kristiansen, Einar Aurbakken, Oyvind Sigmundson Schoyen, Simen Kvaal, Thomas Bondo Pedersen
Summary: Real-time simulations of laser-driven electron dynamics allow for the extraction of molecular optical properties through all orders in response theory. However, accuracy deteriorates for higher-order responses due to nonadiabatic effects caused by the finite-time ramping of the external laser field. Three different approaches for extracting electrical properties from real-time electronic-structure simulations are investigated. Quadratic ramping is found to yield highly accurate results at approximately half the computational cost for polarizabilities, hyperpolarizabilities, and a measure of reliability.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Ignacio Fdez Galvan, Roland Lindh
Summary: In this study, a pseudodiabatic surrogate model is developed based on Gaussian process regression, which accurately reproduces the adiabatic surfaces and significantly reduces the computational effort required to obtain minimum energy crossing points using the restricted variance optimization method.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Andy Kaiser, Razan E. Daoud, Francesco Aquilante, Oliver Kuhn, Luca De Vico, Sergey I. Bokarev
Summary: We implemented the Frenkel exciton model into the OpenMolcas program package to calculate collective electronic excited states of molecular aggregates. Our protocol does not rely on diabatization schemes or supermolecule calculations, and the use of Cholesky decomposition for pair interactions improves computational efficiency. We applied our method to two test systems and compared it with the dipole approximation.
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)
Review
Chemistry, Multidisciplinary
Mickael G. Delcey
Summary: MultiPsi is an open-source MCSCF program that calculates ground and excited states properties of strongly correlated systems. It is written in Python/C++ and is highly modular, making it suitable for development and teaching. The code is also efficient and designed for modern high-performance computing environments.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2023)
Review
Chemistry, Multidisciplinary
Benedicte Sverdrup Ofstad, Einar Aurbakken, Oyvind Sigmundson Schoyen, Hakon Emil Kristiansen, Simen Kvaal, Thomas Bondo Pedersen
Summary: In recent years, there has been growing interest in time-dependent coupled-cluster (TDCC) theory for simulating laser-driven electronic dynamics in atoms and molecules, as well as molecular vibrational dynamics. This review covers different types of single-reference TDCC theory based on orthonormal static, orthonormal time-dependent, or biorthonormal time-dependent spin orbitals. The time-dependent extension of equation-of-motion coupled-cluster theory and various applications of TDCC methods are also discussed, including the calculation of linear absorption spectra, response functions, high harmonic generation spectra, and ionization dynamics. Additionally, the role of TDCC theory in finite-temperature many-body quantum mechanics and other application areas is briefly described.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2023)
Article
Chemistry, Physical
Juliana Cuellar-Zuquin, Ana Julieta Pepino, Ignacio Fdez Galvan, Ivan Rivalta, Francesco Aquilante, Marco Garavelli, Roland Lindh, Javier Segarra-Marti
Summary: We characterized the photochemically relevant conical intersections between different DNA/RNA nucleobases using CASSCF algorithms. Our results show that the size of the active space significantly affects the conical intersection topographies, while the basis set size seems to have a minor effect. We ruled out structural changes as a key factor and highlighted the importance of accurately describing the electronic states involved in these intersections.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Mikael Scott, Mickael G. G. Delcey
Summary: This article presents novel developments for the efficient evaluation of complex linear response functions of a multiconfigurational self-consistent field (MCSCF) wave function. The direct evaluation of linear response properties using the complex polarization propagator (CPP) approach is implemented within both the Tamm-Dancoff approximation (TDA) and the random phase approximation (RPA). The code's performance is illustrated with numerical examples, demonstrating its capability to handle large-scale MC-CPP calculations as well as the effect of including or excluding core orbitals in X-ray spectroscopy for small covalent metal complexes.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Eirill Hauge, Hakon Emil Kristiansen, Lukas Konecny, Marius Kadek, Michal Repisky, Thomas Bondo Pedersen
Summary: We propose a novel function fitting method for approximating the propagation of the time-dependent electric dipole moment from real-time electronic structure calculations. The method achieves arbitrary spectral resolution through extrapolation by fitting shorter dipole trajectories. Numerical testing demonstrates that this fitting method can reproduce high-resolution spectra using short dipole trajectories.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Gabriel L. S. Rodrigues, Mikael Scott, Mickael G. Delcey
Summary: Multiconfigurational pair-density functional theory (MC-PDFT) is an inexpensive way to describe both strong and dynamic correlations. This study demonstrates that the previously neglected imaginary component is actually necessary to reproduce the correct physical behavior, especially in low-spin open shell systems.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Hannes Kneiding, Ruslan Lukin, Lucas Lang, Simen Reine, Thomas Bondo Pedersen, Riccardo De Bin, David Balcells
Summary: This paper introduces a method for studying transition metal complexes (TMCs) using deep graph learning, which utilizes electronic structure data from natural bond orbital (NBO) analysis and develops a representation called natural quantum graph (NatQG). With this method, the quantum properties of TMCs can be predicted, and the performance is better compared to traditional descriptor-based methods.
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)