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
Niels Kristian Madsen, Rasmus Berg Jensen, Ove Christiansen
Summary: The first implementation of tensor-decomposed vibrational coupled cluster response theory for calculating vibrational excitation energies is presented in this study, where the CP-VCC algorithm has been generalized to allow transformations with the Jacobian matrix and a new eigenvalue solver is introduced. Numerical results show that errors introduced by tensor decomposition can be controlled by numerical thresholds, and the approach allows for black-box calculations with minimal user input. Efficient computation of eigenstates of PAHs without explicitly constructed tensors is also demonstrated, improving memory and CPU time compared to full-tensor versions.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Spectroscopy
Yuliya Osika, Maksim Shundalau
Summary: The potential energy curves of the ground and five low-lying excited terms of the RaF molecule were calculated using the Fock-space relativistic coupled theory. Various spectroscopic constants were predicted and a scheme for direct laser cooling was proposed. The study suggests that the A(2)Pi(1/2) -> X-2 Sigma(+) channel in the RaF molecule is an almost ideal case for direct laser cooling.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Optics
Yuliya Osika, Maksim Shundalau
Summary: The ground and five low-lying excited states potential energy curves of RaBr molecule were calculated for the first time using Fock-space relativistic coupled cluster theory. Various properties were predicted, showing potential for direct laser cooling. Comparison with previous theoretical studies of RaF and RaCl molecules was also provided.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2021)
Article
Chemistry, Physical
Sebastian M. Thielen, Manuel Hodecker, Julia Piazolo, Dirk R. Rehn, Andreas Dreuw
Summary: The study introduces the core-valence separation (CVS) approximation applied to unitary coupled-cluster (UCC) theory for calculating core-excited states and simulating x-ray absorption spectroscopy (XAS). Results from CVS-UCC are compared to algebraic-diagrammatic construction methods and experimental data, showing its potential as a new approach for XAS calculations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
Michal Heczko, Ewa Suminska, Dawid Pinkowicz, Beata Nowicka
Summary: A series of new CN-bridged coordination networks with different dimensions and topologies were obtained by modifying the reaction conditions. The reaction pathway was determined by temperature and the addition of LiCl electrolyte. The compounds exhibit paramagnetic behavior, and one of them shows a photomagnetic effect after violet light excitation.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Hongbin Li
Summary: Metalloproteins play crucial roles in biological processes. Single-molecule force spectroscopy is a powerful tool to investigate the folding and unfolding mechanisms of metalloproteins at the single-molecule level, providing insights into their functions and dynamics. Experimental studies of metalloprotein folding are challenging, but single-molecule force spectroscopy has allowed researchers to directly probe the folding and unfolding processes and the impact of metal centers.
Article
Optics
Ravi Kumar, S. Chattopadhyay, D. Angom, B. K. Mani
Summary: A new all-particle Fock-space relativistic coupled-cluster method was developed and successfully applied to calculate clock properties in Al+, yielding results in excellent agreement with experimental values, demonstrating the accuracy and effectiveness of the method.
Article
Mathematics, Applied
Meena Pargaei, B. V. Rathish Kumar
Summary: This study presents a stable numerical method based on Haar wavelets for solving coupled degenerate reaction-diffusion partial differential equations. The method effectively uses a discontinuous basis and is exponentially convergent. Numerical examples demonstrate its good performance.
APPLIED NUMERICAL MATHEMATICS
(2023)
Article
Chemistry, Physical
Zsuzsanna E. Mihalka, Jozef Noga
Summary: The perturbational parameter in the coupled-cluster and perturbation theory frameworks is explicitly included in the Hamiltonian and CC formalism. This paper discusses the properties of amplitude functions dependent on the parameter and proposes an extrapolation scheme to estimate CCSD amplitudes without solving relevant equations, improving the convergence of CC iterations.
Article
Optics
Fang Li, Hong Ma, Yong-Bo Tang
Summary: The hyperfine-structure constants A and B of 24 low-lying states of La2+ are calculated using the singles and doubles approximated relativistic coupled-cluster method. The results show reasonable agreement with experimental values for certain states, but significant deviations for others. The role of electron correlation effects is further investigated using lower-order many-body perturbation theory and coupled-cluster methods.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2021)
Article
Chemistry, Physical
Wojciech Skomorowski, Anna I. Krylov
Summary: This study introduces a novel approach to calculate Auger decay rates by combining Feshbach-Fano resonance theory with the EOM-CCSD framework. The researchers use a core-valence separation scheme to define projectors and represent the continuum many-body decay states using products of appropriate EOM-CCSD states and a free-electron state.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Ruhee D'Cunha, T. Daniel Crawford
Summary: In this study, the efficacy of two variations of the pair-natural-orbital approach, namely PNO++ and combined PNO++, were investigated for reducing the scaling in coupled cluster property calculations. The results showed that for different types of molecules, the truncation errors in response properties were similar for all three methods, while the PNO method performed slightly better than the PNO++ and combined PNO++ methods in terms of correlation energies.
Article
Chemistry, Physical
Wojciech Skomorowski, Anna I. Krylov
Summary: The study introduces a theoretical framework for computing Auger rates and applies it to core-ionized and core-excited benchmark systems. Comparison with experimental spectra shows that the proposed computational scheme provides reliable ab initio predictions of the Auger spectra, with advantages in terms of reliability, cost efficiency, and robust computational setup for a wide range of systems.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Qingguo Lu, Xiaofeng Liao, Shaojiang Deng, Huaqing Li
Summary: This article discusses a multi-node sharing problem and proposes a decentralized stochastic algorithm called VR-DPPD. The algorithm combines the variance-reduction technique with the decentralized proximal primal-dual method. The research shows that VR-DPPD converges linearly to the exact optimal solution if the local functions are strongly convex.
IEEE TRANSACTIONS ON SIGNAL AND INFORMATION PROCESSING OVER NETWORKS
(2022)
Article
Chemistry, Physical
Ch Kavitha, K. Narendra, A. Ratnakar, Nuthalapati Poojith, C. Sampath, Subrata Banik, P. A. Suchetan, Krishna Murthy Potla, Nuthalapati Venkatasubba Naidu
JOURNAL OF MOLECULAR STRUCTURE
(2020)
Article
Chemistry, Multidisciplinary
Subrata Banik, Ankit Kumar Sansi, Shiv Nandan, Tapta Kanchan Roy
Article
Materials Science, Multidisciplinary
Diksha Thakur, Deepak Kumar Dubey, Rohit Ashok Kumar Yadav, Subrata Banik, Jayachandran Jayakumar, Chien-Hong Cheng, Jwo-Huei Jou, Subrata Ghosh
Summary: After the discovery of the impact of nonvisual lighting on human health, lighting engineers are focusing more on developing cost-effective and efficient human-friendly lighting. The solution-processed fabrication method for high efficacy OLED devices is expected to significantly reduce costs. The use of co-host matrix has the potential to enhance device performance multiple times, while a well-designed device architecture can improve energy transfer efficiency.
ORGANIC ELECTRONICS
(2021)
Article
Chemistry, Multidisciplinary
Krishan Kumar, Kiran Kishore Kesavan, Diksha Thakur, Subrata Banik, Jayachandran Jayakumar, Chien-Hong Cheng, Jwo-Huei Jou, Subrata Ghosh
Summary: The performance of newly developed functional pyrene derivatives with different functionalized pyridine units as hole-transporting materials for OLED applications was studied, showing stable performance and desirable characteristics in terms of electro-optical properties and device performance.
Article
Chemistry, Physical
Lalitha Ravichandran, Subrata Banik
Summary: The study shows that the inclusion of additional valence s and p orbitals in the basis set leads to unphysical large anharmonicities of OOPB vibrations with the MP2 method. The erroneous VMOs generated by the additional orbitals create a disbalance between the sigma and pi correlations, resulting in errors in the derivatives of the correlation energy. Higher angular momentum polarization atomic orbitals and d and f orbitals on the C atoms in the basis set significantly reduce the unphysical frequencies for the OOPB modes in MP2 calculations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Physical
Krishan Kumar, Kiran Kishore Kesavan, Sunil Kumar, Subrata Banik, Jayachandran Jayakumar, Liang Yu Hong, Lin Yu Hung, Mangey Ram Nagar, Jwo-Huei Jou, Subrata Ghosh
Summary: While OLED technology is evolving rapidly, flexible and eco-friendly display panels with low power consumption provide better options. This study reports on a new hole transporting material called CDP, which shows high performance in OLED devices compared to traditional materials. The CDP-based OLED exhibits higher efficiency and brightness, indicating the potential of the designed material.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Mangey Ram Nagar, Krishan Kumar, Dovydas Blazevicius, Raminta Beresneviciute, Gintare Krucaite, Daiva Tavgeniene, Chen Tun Hao, Subrata Banik, Jwo-Huei Jou, Saulius Grigalevicius
Summary: Solution-processable bipolar carbazole-benzophenone derivatives were successfully synthesized as host materials for green TADF organic LEDs. These hosts exhibited high-triplet energies, balanced charge-transporting properties, and good solubility, leading to excellent device performance.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Krishan Kumar, Anirban Karmakar, Feng-Rong Chen, Jwo-Huei Jou, Subrata Ghosh, Subrata Banik, Sunil Kumar
Summary: The development of highly efficient hole transport materials for OLED devices has been a challenge. This study demonstrates the development of two hetero-arylated pyridines as high triplet energy multifunctional hole transport materials to improve charge carrier recombination in the emissive layer. The theoretical calculations and experimental results support the promising hole transportability of these materials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Nivedhitha Palanisamy, Subrata Banik
Summary: We propose an approximation to the VCCM method for describing the CH-stretching region of large molecule's vibrational spectrum. The molecule's vibrational modes are divided into target set and bath set. The target set includes CH stretches and modes strongly coupled with CH stretches and/or involving strong Fermi resonances. The rest of the modes belong to the bath set. The VCCM equations are constructed with the modified potential from the EHO calculations and only for the target set, and transition energies and intensities are calculated using this truncated VCCM approximation. The method is applied to calculate the IR spectra of naphthalene and anthracene, and compared with experimental IR spectra using three different criteria for selecting modes in the target set.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Krishan Kumar, Mangey Ram Nagar, Anirban Karmakar, Feng-Rong Chen, Jwo-Huei Jou, Subrata Ghosh, Sunil Kumar, Subrata Banik
Summary: This study investigated how the peripheral substituents of a pyridine core affect the hole transport materials (HTMs) for organic light-emitting diodes through experimental and theoretical studies. The results showed that the functionalization of the materials led to a reduction in hole reorganization energy and enhanced hole transport properties. The molecular arrangement and the number of peripheral carbazole units also played a significant role in the performance of the materials. The experiment demonstrated that P0C3Py molecule exhibited good hole-transporting characteristics and can be used as an efficient HTM in OLEDs.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Engineering, Electrical & Electronic
Diksha Thakur, Mangey Ram Nagar, Anju Tomar, Deepak Kumar Dubey, Sunil Kumar, Sujith Sudheendran Swayamprabha, Subrata Banik, Jwo-Huei Jou, Subrata Ghosh
Summary: A strategy for developing an in-depth understanding of the synergy between triplet energy (E-T) and structural composition of molecular hosts for organic light-emitting diodes (OLEDs) was presented, involving virtual screening and experimental validation. Structural changes in molecular hosts were found to enhance device performance, with E-T values significantly impacting efficacy. The study observed a remarkable increase in power efficacy through strategic molecular design.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Physical
Swati Yadav, Subrata Banik, M. Durga Prasad
Summary: The study analyzed the nature of wavefunctions in the CH stretching region for medium sized molecules, finding that optically bright transitions are numerous and spread over a wide range. The final states are superpositions of multiple zeroth order states, with multiquantum states dominating and the CH chromophore contributing little weight.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Diksha Thakur, Deepak Kumar Dubey, Rohit Ashok Kumar Yadav, Mangili Venkateswarulu, Subrata Banik, Jwo-Huei Jou, Subrata Ghosh
JOURNAL OF MATERIALS CHEMISTRY C
(2020)
Article
Chemistry, Multidisciplinary
T. Dinesh, Subrata Banik
JOURNAL OF CHEMICAL SCIENCES
(2019)
