ABSTRACT This study presents the design and analysis of five acceptor–donor–acceptor (A–D–A) type donor molecules ( QABT1 – QABT5 ) by incorporating 2,1,3‐benzothiadiazole (BT) derivatives as electron‐withdrawing acceptor groups into a synthesized reference molecule ( R ) for organic solar cell (OSC) applications. Density functional theory (DFT) and time‐dependent DFT (TD‐DFT) methods were employed to explore the impact of acceptor modifications on the structural, electronic, optical, charge transport, and photovoltaic properties of the designed molecules. The results indicate that introducing strong electron‐withdrawing groups significantly enhances overall device performance. The structural modifications lead to reduced HOMO–LUMO band gaps (2.02–2.36 eV), facilitating efficient charge transfer (CT) and extending the absorption spectra. All designed molecules exhibit broader and red‐shifted absorption in both gaseous and solvent phases, along with lower optical band gaps and reduced exciton binding energies, improving exciton dissociation and charge transport efficiency compared to the reference molecule. Among the designed molecules, QABT4 and QABT5 emerge as the most promising candidates, exhibiting a small optical band gap (1.75 eV), extended excited‐state lifetime (9.65 ns), and low reorganization energies for electrons ( λ e ∼97 meV) and holes ( λ ℎ ∼120 meV). Additionally, the strong push‐pull mechanism results in efficient intramolecular CT, with above 85% CT excitations. These properties contribute to an enhanced short‐circuit current density (J sc ∼13.73 mA/cm 2 ), high open‐circuit voltage (V oc ∼1.46 V) with minimal energy loss (0.57 eV), and a theoretical power conversion efficiency (PCE) up to ∼18%. These findings underscore QABT4 and QABT5 as promising candidates for high‐performance OSCs, paving the way for next‐generation optoelectronic applications.

ABSTRACT Accurate modeling of CO adsorption on copper surfaces is essential for catalytic processes such as syngas conversion and methanol synthesis. However, standard generalized gradient approximation (GGA) functionals cannot reproduce physical site preferences due to the “CO adsorption puzzle.” Nonetheless, resolving site preference alone does not ensure a computationally feasible methodology for studying catalytic COCu systems. A systematic approach is required to identify a balanced framework that is both accurate and feasible for large‐scale catalytic studies. Thus, this work systematically evaluates the effects of basis sets, exchange functionals, dispersion and Hubbard‐U adjustments for CO adsorption on Cu(100), Cu(110), Cu(111), and Cu(211) surfaces using periodic DFT computations. While experimentally observed on‐top adsorption can be achieved using the Hubbard‐U correction, dispersion corrections only improve adsorption energy agreement with experimental data, not the site preference. Among the tested setups, projector augmented‐wave method with the Perdew–Burke–Ernzerhof exchange‐correlation (PAW‐PBE) with U = 8 eV and Grimme‐D3 dispersion correction emerged as a reliable and efficient combination, consistently reproducing adsorption energies and vibrational properties in agreement with experimental reports. To validate this setting in catalytic CO–Cu systems, the approach was extended to methanol adsorption. This work provides a unified, computationally efficient DFT + U + D3 protocol that reproduces experimental CO adsorption behavior and can be readily applied to other catalytic Cu systems.

ABSTRACT Fluorine is commonly incorporated into pharmaceuticals to enhance properties such as metabolic site blocking. However, the Smoothened receptor (SMO) inhibitor, 2,4‐Difluoro‐benzylphthalazine derivative, undergoes metabolism by CYP450 to generate toxic quinone species. A combination of reactivity and accessibility is employed to demonstrate that the quinone production involves hydrogen abstraction from benzyl instead of the phenyl epoxidation mechanism. The main metabolite of fluorine‐containing benzylphthalazine derivatives is benzyl hydroxylation derivatives, which corroborates well with experimental observations. The rate‐determining step in the epoxidation process is a CO bond formation, leading to the production of a radical species instead of a carbocation intermediate. The substitution of F with groups such as CF 3 or CN can increase the energy barrier associated with CO bond formation, thereby augmenting the difficulty in producing quinones. The present study provides a theoretical foundation for the drug metabolism and drug design of pharmaceuticals containing fluorine atoms.

ABSTRACT The luminescence characteristics of small molecules excited BN superatoms remain unexplored, despite their potential applications in material luminescence. In this study, we investigated the absorption and fluorescence emission spectra of three small molecules (pyrazine, pyridine, and benzene) adsorbed on B 16 N 16 using first principle. Our results reveal that pyridine and pyrazine form stable chemisorption structures, namely pyrazine‐B 16 N 16 and pyridine‐B 16 N 16 , while benzene forms a physisorption structure, benzene‐B 16 N 16 ‐4V, upon adsorption. Both the chemisorption of pyrazine and pyridine and the physisorption of benzene strengthen the emission spectrum intensity of B 16 N 16 , but the enhancement effect of the former is more pronounced. Additionally, the influence of varying numbers of small molecule adsorption on spectral characteristics is discussed, noting that the adsorption of multi‐small molecules weakens the absorption and emission spectra. The optical band gap analysis indicates that pyrazine‐B 16 N 16 has a narrower optical band gap than B 16 N 16 , pyridine‐B 16 N 16 , and benzene‐B 16 N 16 ‐4V, suggesting that the pyrazine‐adsorbed system is more readily excited. These findings present a strategic approach to luminescent materials and serve as a theoretical foundation for experimental investigations.

ABSTRACT A global potential energy surface (PES) for the CH 2 (1 1 A′) was constructed using neural network method based on high‐level ab initio points. The topographic features of the PES were discussed and compared with available theoretical and experimental values. The results indicate that the present PES is accurate and reliable. To further clarify the reality of the PES, the dynamics calculations of the C( 1 D) + H 2 → H + CH(X 2 Π) reaction were performed using time‐dependent wave packet method. Some meaningful dynamic results including reaction probability, integral cross section, differential cross section, and rate constant were calculated and compared with previous theoretical and experimental values. The reasonable dynamics results indicate that the present PES can be used to perform any kind of dynamics studies.

ABSTRACT This work presents an improved version of the residual vector correction (RVC) algorithm, designed to address the eigenproblem involved in electronic structure calculations. Instead of directly diagonalizing the entire Hamiltonian matrix, the proposed algorithm iteratively diagonalizes a 2 × 2 submatrix, focusing only on the relevant molecular orbitals. Molecular orbital energies are iteratively minimized along a residual vector, with the step size determined by diagonalizing the 2 × 2 submatrix. To obtain the subsequent eigenvalues, we employ Hotelling deflation, which constructs the necessary auxiliary Fock matrix. Since the size of the diagonalized matrix does not increase with the molecular system, this algorithm eliminates the cubic scaling dependence of computational efficiency on molecule size seen in direct diagonalization. Compared to the earlier version, the implementation within the Hartree–Fock framework shows that the current version is significantly more practical for the calculation of considerably large molecules. As demonstrated, the RVC method consistently surpasses existing iterative approaches in efficiency while maintaining high accuracy.

ABSTRACT Lithium‐ion batteries (LIBs) have dominated the energy storage field due to their high energy density, long cycle life, and environmental friendliness. In this study, we systematically investigated the electrochemical properties of phosphorus (P)‐doped γ‐graphyne as a promising LIBs anode material using density functional theory calculations. The formation energy and cohesive energy of γ‐graphyne at varying doping concentrations are calculated, demonstrating excellent experimental synthesizability of P‐doped γ‐graphyne. Notably, the P‐doped system exhibits enhanced electrical conductivity compared to pristine γ‐graphyne. The adsorption energy of a single lithium (Li) atom on P‐doped γ‐graphyne is determined to be −3.72 eV, significantly higher than those of N‐doped, Si‐doped, and intrinsic γ‐graphyne. Even with increasing Li storage, the Li adsorption energy remains greater than the cohesive energy of bulk lithium, while the average open‐circuit voltage falls within the optimal range of 0–1 V, ensuring high operational safety. Remarkably, the theoretical Li storage capacity of P‐doped γ‐graphyne reaches 1150.68 mAh/g, which is 1.85 times that of pristine γ‐graphyne and 3.09 times that of conventional graphite. Furthermore, the diffusion barrier calculations reveal that P‐doped γ‐graphyne substantially reduces the Li‐ion migration energy barrier, indicating favorable lithium diffusion kinetics. In summary, P‐doped γ‐graphyne demonstrates exceptional advantages in specific capacity, structural stability, electrical conductivity, and Li‐ion diffusion kinetics, providing critical theoretical insights and experimental guidance for designing next‐generation high‐performance LIBs anode materials.