Article
Materials Science, Multidisciplinary
J. W. Zwanziger, M. Torrent, X. Gonze
Summary: We demonstrate the computation of orbital magnetization within the PAW formalism of density functional theory for systems with periodic boundary conditions. Magnetic translation symmetry and a perturbative treatment of the density operator are utilized to accurately account for all PAW terms. The implementation of our expressions, which can be used to compute wave-function derivatives using density functional perturbation theory, has been tested and verified for both atoms and solids.
Article
Materials Science, Multidisciplinary
C. N. Brock, B. B. Baer, D. G. Walker
Summary: Treating 3d electrons as core electrons in the new PAW data set speeds up defect calculations in GaN without adversely affecting the results, with potential speedups in Born-Oppenheimer molecular dynamics studies of GaN defects.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Subrata Jana, Hemanadhan Myneni, Szymon Smiga, Lucian A. Constantin, Prasanjit Samal
Summary: In this study, the performance of dispersion corrected revised Tao-Mo (revTM) semilocal functionals in various areas such as thermochemistry, different crystal structures, and metal-organic systems is reviewed. It is found that modifications are needed for the revTM function to adapt to the diverse properties of finite and extended systems. The revised revTM+D3 functional provides molecular and solid properties that are closer to experimental findings compared to its predecessor, making it a cost-effective method for simulations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Mengqin Liu, Tao Han, Xinran Hu, Yubing Tu, Zongyuan Zhang, Mingsheng Long, Xingyuan Hou, Qingge Mu, Lei Shan
Summary: The study investigates the tuning of superconductivity and charge density wave in CsV3Sb5 through V kagome net doping. Ta doping promotes superconductivity but suppresses charge density wave, while Mo doping quickly suppresses superconductivity and leads to an increase in charge density wave temperature.
Article
Chemistry, Multidisciplinary
Stephane Kenmoe, Dick Hartmann Douma, Abdulrafiu Tunde Raji, Bernard M'Passi-Mabiala, Thomas Goetsch, Frank Girgsdies, Axel Knop-Gericke, Robert Schloegl, Eckhard Spohr
Summary: Combining theoretical and experimental X-ray absorption near-edge spectroscopy (XANES) to probe the local environment around cationic sites in bulk spinel cobalt tetraoxide (Co3O4), we found a strong pre-edge peak in the oxygen K-edge spectrum. The contributions to the pre-edge peak from Co2+ ions are solely due to single spin-polarized t(2g) orbitals, while those from Co3+ ions are due to spin-up and spin-down polarized eg orbitals. Additionally, the magnetic moments on the Co3+ and Co2+ ions were determined to be zero and 3.00 mu B respectively, consistent with previous experimental findings of antiferromagnetically ordered Co2+ spins in Co3O4.
Article
Materials Science, Multidisciplinary
Haruki Hirai, Takumi Iizawa, Tomoyuki Tamura, Masayuki Karasuyama, Ryo Kobayashi, Takakazu Hirose
Summary: This paper proposes a machine-learning-based method for predicting the x-ray absorption near-edge structure (XANES) for local configurations specific to amorphous materials. The method combines molecular dynamics and first-principles XANES simulations, assuming that the XANES spectrum can be accurately represented by linear regression of the local atomic descriptors. A comprehensive prediction of Si K-edge XANES spectra is performed using various techniques, including atom-centered symmetry function, smooth overlap of atomic positions, local many-body tensor representation, and spectral neighbor analysis potential. Furthermore, the prediction accuracy is improved through compression of XANES spectral data and efficient sampling of training data.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Condensed Matter
Sebastian Echeverri Restrepo
Summary: The effects of molybdenum as a substitutional element in cementite phase in steels were investigated. It was found that the addition of molybdenum can improve the hardness of steel at higher temperatures. The energetic, structural, electronic, and mechanical properties of cementite with molybdenum were characterized and analyzed.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
N. A. W. Holzwarth, Marc Torrent, Jean-Baptiste Charraud, Michel Cote
Summary: Recent developments in functionals that depend on the kinetic energy density have shown significant improvements in the computational representation of real material properties. By implementing these forms within plane-wave codes using pseudopotentials and an efficient solver, promising preliminary results for several simple materials have been achieved.
Review
Chemistry, Multidisciplinary
Karol Kowalski, Raymond Bair, Nicholas P. Bauman, Jeffery S. Boschen, Eric J. Bylaska, Jeff Daily, Wibe A. de Jong, Thom Dunning, Niranjan Govind, Robert J. Harrison, Murat Keceli, Kristopher Keipert, Sriram Krishnamoorthy, Suraj Kumar, Erdal Mutlu, Bruce Palmer, Ajay Panyala, Bo Peng, Ryan M. Richard, T. P. Straatsma, Peter Sushko, Edward F. Valeev, Marat Valiev, Hubertus J. J. van Dam, Jonathan M. Waldrop, David B. Williams-Young, Chao Yang, Marcin Zalewski, Theresa L. Windus
Summary: Chemists have been utilizing computers since the beginning to understand and solve complex chemical problems. With advancements in hardware and software, the field of theoretical and computational chemistry has evolved. Transitioning software from terascale to petascale and now to exascale computers presents challenges and opportunities for tackling large scientific challenges. One example highlighted is the NWCHEM and its redesign, NWCHEMEX, which is a codesign project aiming to take advantage of massively parallel computers and emerging software standards.
Article
Chemistry, Physical
Jared R. Williams, Nicolas Tancogne-Dejean, Carsten A. Ullrich
Summary: Time-dependent density-functional theory (TDDFT) is an efficient method for calculating optical spectra, providing insight into exciton dynamics by obtaining exciton wave functions and understanding the formation and dissociation of excitons in real time.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Optics
Zainab N. Jaf, Hussein A. Miran, Imad H. Khaleel, Kareem A. Jasim
Summary: This contribution provides an atomistic understanding of the impact of W, Nb, and Mo co-substitution at the Hf-site of the cubic HfO2 lattice to produce the Hf(1_x)TMxO(2) system at x = 25%. The calculations were performed using density functional theory (DFT) supported by Habbured parameter (DFT+U). The results show that the lattice constants are consistent with previous studies, with a contraction of 1.33% compared to the host system. The doping effect of TM on the band gap leads to its reduction in the resulting Hf0.75TM0.25O2 configurations. Optical analysis reveals that Hf0.75TM0.25O2 systems can absorb a broad range of UV electromagnetic waves, making them suitable candidates for optoelectronic devices.
Article
Physics, Condensed Matter
Shahran Ahmed, Sadiq Shahriyar Nishat, Alamgir Kabir, A. K. M. Sarwar Hossain Faysal, Tarique Hasan, Shovon Chakraborty, Imtiaz Ahmed
Summary: In this study, first principles simulations were used to investigate the structural, elastic, vibrational, electronic, and optical properties of orthorhombic samarium orthoferrite SmFeO3 based on density functional theory. The study utilized various density functionals to model the electron exchange-correlation, with Heyd-Scuseria-Ernzerhof functional showing better modeling for localized d and f orbitals in SFO. The results provide a comprehensive theoretical analysis of the properties of SFO.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Neurosciences
Rawan S. Alnafisah, James Reigle, Mahmoud Ali Eladawi, Sinead M. O'Donovan, Adam J. Funk, Jaroslaw Meller, Robert E. Mccullumsmith, Rammohan Shukla
Summary: Antipsychotic drugs have a significant impact on postmortem studies of schizophrenia treatment. This study compares the effects of schizophrenia and antipsychotic drugs on the proteome to gain insight into the disease's pathophysiology. The findings reveal distinct changes in biological pathways, cell types, subcellular synaptic events, and drug targets between the two. The study identifies a hyperdopaminergic cortex and discusses the influence of drugs targeting cognitive symptoms on schizophrenia pathology.
NEUROPSYCHOPHARMACOLOGY
(2022)
Article
Environmental Sciences
Aina Barcelona, Carolyn Oldham, Jordi Colomer, Teresa Serra
Summary: The study found that seagrasses may exhibit two different behaviors in water flow, depending on canopy density, patch size, and wave velocity. High canopy density, large patches of vegetation, or moderate wave speed will result in plant-wave interaction, while low canopy density, small patches of vegetation, or slow wave speed will lead to behaviors similar to non-vegetated cases.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Multidisciplinary Sciences
Menghan Liao, Heng Wang, Yuying Zhu, Runan Shang, Mohsin Rafique, Lexian Yang, Hao Zhang, Ding Zhang, Qi-Kun Xue
Summary: The authors observed magnetoresistance oscillations and an anomalous metal state due to the coexistence of superconductivity and charge density wave in lithium intercalated TiSe2. They induced a superconducting dome in the phase diagram of LixTiSe2 and observed periodically arranged superconducting arrays around optimal doping. Additionally, they observed an anomalous metal state with resistance plateau below the superconducting transition.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Condensed Matter
Arghya Ghosh, Subrata Jana, Manish K. Niranjan, Sushant Kumar Behera, Lucian A. Constantin, Prasanjit Samal
Summary: This study finds that the meta-generalized gradient approximation (meta-GGA) obtained from the cuspless hydrogen density (MGGAC) performs well in understanding the electronic properties of chalcopyrites, with comparable bandgaps to state-of-the-art hybrid methods. The study also highlights the importance of the Pauli kinetic energy enhancement factor in describing the d electrons in chalcopyrites. Therefore, the MGGAC functional within semilocal approximations can be a better choice for studying chalcopyrites and other solid-state systems due to its superior performance and significantly low computational cost.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Bidyadhar Das, Madhusmita Sahoo, Abhilash Patra, Ashok K. Yadav, S. N. Jha, Prasanjit Samal, Kartik Senapati, Pratap K. Sahoo
Summary: This study explores the feasibility of using X-ray Absorption Spectroscopy (XAS) to track changes in the local bonding environment in NiBi3 and NiBi systems. The decomposition of NiBi3 into NiO and Bi during thermal annealing was successfully tracked through changes in structural and magnetization behavior, which correlated well with the findings from XAS. The study also revealed that NiO becomes the dominant phase at 500 degrees C annealing temperature, as confirmed by magnetic hysteresis measurements and XAS.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Meenakshi Talukdar, Sushant Kumar Behera, Subrata Jana, Prasanjit Samal, Pritam Deb
Summary: Engineering 2D heterostructures can enhance photocatalytic performance for dye degradation. This study analyzed the band alignment of a 2D/2D heterojunction and confirmed its desired type-II band alignment, which facilitates rapid separation of photogenerated carriers and efficient photocatalytic degradation.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Physical
Subrata Jana, Lucian A. Constantin, Szymon Smiga, Prasanjit Samal
Summary: The reverse-engineered semilocal exchange hole model is useful for designing hybrid density functionals for challenging compounds. This method has important applications in materials science and has been validated.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Selin Bac, Abhilash Patra, Kareesa J. Kron, Shaama Mallikarjun Sharada
Summary: This paper provides an overview of state-of-the-art techniques for efficiently calculating second and higher nuclear derivatives of quantum mechanical energy. Machine learning, automatic differentiation, and matrix completion are emerging methods that show promise in overcoming the challenges of high costs and memory for such calculations. These methods enable reliable predictions of quantum mechanical energy responses to nuclear perturbations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Arghya Ghosh, Subrata Jana, Manish K. Niranjan, Fabien Tran, David Wimberger, Peter Blaha, Lucian A. Constantin, Prasanjit Samal
Summary: This study demonstrates that the use of the MGGAC method can accurately calculate the ground-state phase of MnO, consistent with results from high-level correlation methods. Additionally, the use of hybrid functionals (including Hartree-Fock exchange) can also yield the correct ground-state phase. These methods have the advantage of being computationally inexpensive when calculating the relative stability of antiferromagnetic transition-metal oxides.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Gurupada Ghorai, Kalyan Ghosh, Bidyadhar Das, Subhashree Sahoo, Bikash Patra, Prasanjit Samal, Pratap K. Sahoo
Summary: Manipulating light at the sub-wavelength level is crucial for surface plasmon resonance (SPR) properties. Noble metals like Au and Ag are commonly used for SPR, but this study explores chromium (Cr) as an alternative plasmonic material. Cr micro-rods were synthesized and their plasmonic modes were observed using optical absorption and cathodoluminescence imaging spectroscopy. The observed emission peaks match the band transitions obtained from density functional theory calculations. These findings expand the range of plasmonic materials beyond noble metals for tunable plasmonic emissions in optical technology.
Article
Chemistry, Physical
Subrata Jana, John M. M. Herbert
Summary: The methods for computing core-level ionization energies are evaluated and compared. The full core hole approach and Slater's transition concept are considered, with the latter showing mean errors of 0.3-0.4 eV compared to experiment. A shifted Slater transition method requiring only initial-state Kohn-Sham eigenvalues is found to be a simple and practical way to compute core-level binding energies. It is particularly useful for simulating transient x-ray experiments.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Abhilash Patra, Anna I. Krylov, Shaama Mallikarjun Sharada
Summary: Exciplexes are formed when one moiety of the donor-acceptor pair is electronically excited, and the exciplex formed between OPP and TEA can hinder the generation of the necessary radical anion for CO2 reduction. This study develops a workflow for automating quantum-chemistry calculations to generate and characterize an ensemble of structures representing the exciplex state, improving the agreement with experimental results.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Subrata Jana, Lucian A. Constantin, Prasanjit Samal
Summary: We propose a realistic density functional approximation based on a semilocal indicator that exhibits good screening properties. The local band model shows remarkable density scaling behaviors and is applicable to various atoms. We introduce the LDAg correlation functional, which correctly calculates the correlation energy of atoms and shows improvement in ionization potential.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Review
Multidisciplinary Sciences
Naline Gandhi, Amatullah Sana Qadeer, Ananda Meher, Jennifer Rachel, Abhilash Patra, Jebamalar John, Aiswarya Anilkumar, Ambarish Dutta, Lipika Nanda, Sarit Kumar Rout
Summary: The main objective of this review is to summarize the evidence on the core modelling specifications and methodology on the cost-effectiveness of TKR compared to non-surgical management. Another objective is to synthesize evidence of TKR cost and compare it across countries using purchasing power parity (PPP). The findings showed that the Markov model was most widely used in the analysis of the cost effectiveness of TKR and the cost of TKR was higher in developed countries than in developing countries.
Article
Materials Science, Multidisciplinary
Subrata Jana, Arghya Ghosh, Lucian A. Constantin, Prasanjit Samal
Summary: A simple and effective screening parameter is constructed for the screened range-separated exchange-correlation hybrid functional based on the compressibility sum rule in the context of linear-response time-dependent density functional theory. When applied to the dielectric-dependent hybrid (DDH), it shows remarkable accuracy for bulk solids compared to parameters obtained from fitting with the model dielectric function or depending on the valence electron density of materials. The screening parameter developed in this study is simple, realistic, and physically appealing, and can be easily obtained using the average of the local Seitz radius over the unit-cell volume of the bulk solid. Furthermore, the constructed DDH demonstrates very good accuracy in energy band gaps, occupied d band positions, ionization potentials, optical properties of semiconductors and insulators, and geometries of bulk solids (equilibrium lattice constants and bulk moduli).