International Journal of Quantum Chemistry最新文献

This investigation employed computational methodologies to assess the therapeutic potential of derivatives (1–16) of pyridoxal isonicotinoyl hydrazone (PIH) as potential treatments for tuberculosis. Various computational techniques, including molecular dynamics simulation, molecular docking, density functional theory, and global chemical descriptors, were employed to analyze the interactions between the ligands and target proteins. Docking results indicated that ligands 6, 7, 8, and rifampin exhibited binding affinities of −8.4, −7.4, −9.2, and − 7.2 kcal mol⁻¹, respectively, against mycobacterium tuberculosis enoyl acyl carrier protein reductase (INHA), with ligand 8 demonstrating superior inhibition. Molecular dynamics (MD) simulations were utilized to assess the stability of protein-ligand interactions. Remarkably, the Root Mean Square Deviation (RMSD) of the INHA-ligand 8 complex remained minimal, with peak values at .40, .56, .37, and .50 nm at temperatures of 300, 305, 310, and 320 K, respectively. This suggests superior stability compared to the reference drug rifampin and INHA complex, which exhibited an RMSD range of .2 to .8 nm at 300 K. Furthermore, analysis using Frontier Molecular Orbital (FMO) revealed that the Egap value of ligand 8 (4.407 eV) is lower than all the reference drugs except rifampin. This comprehensive theoretical analysis positions ligand 8 as a promising candidate for anti-tuberculosis drug development, underscoring the need for further exploration through in vitro and in vivo studies.

Due largely to the high stability and the potential ozone-depleting, the transformation of greenhouse gas nitrous oxide has gained much attentions. In present paper, a new insight into the deoxygenation of nitrous oxide with silane was reported by using oriented external electric field (OEEF) as a catalytic strategy. When the OEEF was employed, the reaction barrier of deoxygenation was marvelously decreased as it was oriented along the positive NO/OSi bond-axis. Especially the field strength is 300 × 10⁻⁴ a.u., the differences are up to 22.4/18.3 kcal mol⁻¹ as compared with that of nonfield. In addition, once the H atom in SiH₄ was replaced by methyl, two reaction modes were obtained, in which the deoxygenation process was easier when the N₂O captured the H atom attached to the Si atom, not attached to the C atom. Further, the solvent effects of deoxygenation reaction were also considered, but with a weak influence were obtained.

Making products that are affordable, environmentally friendly, and energy-efficient is the main objective of modern production. The objective of this research is to discover compounds that meet these parameters. The full-potential, linearized augmented plane wave program (FP LAPW) offered by Wien2K was used to examine the structural, optical, electrical, and transport aspects of SrCaGe and SrCaSn Half-Heusler (HHs) compounds. Generalized gradient approximation (GGA) was considered for the structural optimization and computation of elastic properties signifies inherent ductility and mechanical stability of the examined SrCaGe and SrCaSn compounds. Additionally, both materials were found to possess a direct bandgap and exhibit semiconducting behavior. The bandgap magnitudes obtained utilizing the modified Becke-Johnson (mBJ) approximation are 0.78 and 0.52 eV for SrCaGe and SrCaSn, respectively. According to their optical characteristics, SrCaGe and SrCaSn show potential for application in optoelectronic components. Furthermore, the transport properties are evaluated by BoltzTrap program, revealing that both SrCaGe and SrCaSn exhibit figures of merit (ZT) values nearly equal to one at room temperature. This suggests their potential use in creating thermoelectric devices with highly efficient performance. The simulation study demonstrates the promising attributes of SrCaGe and SrCaSn HHs materials, positioning them as viable candidates for various applications, aligned with the goals of sustainable and efficient manufacturing.

Chemical graph theory facilitates different tools that have significant applications in drug design and development. Recently Gutman et al., introduced a novel vertex-degree-based topological index called elliptic Sombor index and its application through geometric approach. This article focuses on chemical applicability of elliptic Sombor index through regression models using 22 benzenoid hydrocarbons. In this process, the chemical applicability of elliptic Sombor index with various physicochemical properties of benzenoid hydrocarbons through curvilinear regression models is carried out. The data of the statistical analysis shows that elliptic Sombor index is potential predictive index for the property polarizability.

Rovibrational configuration interaction theory has been used to study the rotational spectrum and low lying rovibrational states of thiopropynal, a molecule, which has recently been detected in an interstellar cloud. Geometrical parameters, fundamental vibrational transitions and spectroscopic constants are also provided. All calculations rely on an $��n�$-mode representation of the multidimensional potential energy surface, which has been obtained from explicitly correlated coupled-cluster approaches including core correlation effects and an approximate treatment of high-order coupled-cluster terms. Comparison with experimental data is provided for several properties and the agreement was found to be excellent in most cases.

Production of ammonia (NH₃) by electrocatalytic reduction of nitrate (NO₃RR) not only eliminates harmful pollution, but also provides a way to reduce the energy consumption associated with predominated Haber-Bosch process. However, realization of this process still faces many challenges because of the complexity of the reaction mechanism. Here we investigated the catalytic activity and selectivity of a series of graphdiyne supported single atom catalysts (SACs), namely TM/GDY, for the reduction of N$��O_3^{-}�$ to NH₃ by first-principles calculations. Among the 10 SACs studied, Fe/GDY was found to have good catalytic performance, consistent with the fact that the Fe-doped GDY molecular layer was located near the top of the volcano plot, with a reaction limit potential of −0.44 V and showed excellent selectivity in inhibiting the competitive hydrogen evolution reaction (HER). The formation of the by-products NO₂, NO, N₂O and N₂ on Fe/GDY requires a considerable energy barrier, which ensures high selectivity. Furthermore, detailed electronic property analyses indicate that the GDY can work as an electron repository to effectively balance the charge transfers during the reaction process. This study not only offers an eligible NO₃RR electrocatalyst but also provides an atomic understanding of the mechanisms of the NO₃RR process behind.

This contribution reports extensive studies on structure–property correlations of two isoelectronic betaine metamers (positional isomers). These zwitterions differ from each other with respect to bonding modes of pyridinium acceptors (Reichardt's mode: through N-atom versus Brooker's mode: through C-atom) with the p-phenylene bridged phenolate donors. Various quantum chemical methodologies are used in this investigation, with time-dependent (TD) and coupled perturbed (CPHF) theories for computations of many molecular response properties. Analysis of first hyperpolarizabilities (β) indicates that Reichardt's metamer (ωB97xD: β = 349.5 × 10⁻³⁰ esu) is more efficient chromophore (~5-fold enhanced) than Brooker's metamer (ωB97xD: β = 69.4 × 10⁻³⁰ esu). The gyratory abilities of the bridge junctions resulted in a cohort of metastable conformations, in the rotational potential energy surfaces (PES) of the two metamers. Moreover, rotational PES establishes that intermediary torsions are suitable for optimal chromophore design strategies (Reichardt's metamer: β = 956.5 × 10⁻³⁰ esu, and Brooker's metamer: β = 1104.7 × 10⁻³⁰ esu), Thus suitable conformational manipulations, can be used to obtain more efficient zwitterionic molecular chromophores. Compared unbridged prototype molecules, p-phenylene bridged zwitterions showed ~6–9 times enhanced values of β. In addition, important aspects of suitable chromophore design strategies are suggested.

To efficiently desorb H₂, pure Mg_n (n = 4–8) clusters were chosen for the hydrogen evolution reaction with H₂O. At the PBE0/def2-TZVP level and the PBE0-D3/def2-TZVP level, the lowest energy structures of Mg_n (n = 4–8) clusters and the most stable structures of Mg_n@H₂O (n = 4–8) complexes were searched in the local region. The transition state was predicted, and then the hydrogen evolution reaction channel was obtained by using the intrinsic reaction coordinate (IRC) to confirm the transition state. To better analyze the hydrogen reaction mechanism, the character of Mg_n@H₂O (n = 4–8) complexes and Mg_nO (n = 4–8) clusters, as well as the atomic charge change trend, were investigated using interaction region indicator function analysis (IRI) and natural population analysis (NPA). The reaction effect of Mg₄ cluster and H₂O is the worst. The energy barrier does, however, progressively lower as the cluster atom count rises, improving the reaction effect.

Based on the improved multiparameter exponential-type potential (IMPET), an extended IMPET (EIMPET) potential has been suggested to reduce the discrepancy between the calculated and experimental values, improving the accuracy near the equilibrium and in the asymptotic region. The average fitting deviation δ_av and Root-Mean-Square (RMS) error is used to evaluate the performance of the potential which generates potential energy curves (PECs) and vibrational energy levels for ClF-A(³Π₁), CP-X²Σ⁺, ICl-X¹Σ⁺, IBr-X¹Σ⁺, CO-X¹Σ⁺, and ⁶Li₂-X¹Σ⁺ molecules that agree better with the Rydberg-Klein-Rees (RKR) data than Morse, Huxley-Murrell (HM) and IMPET potentials. This work provides a reference for the construction and improvement of potential energy functions for diatomic molecules.

The stabilities, mechanical, electronic, and magnetic properties of the new equiatomic quaternary Heusler alloy (EQHA) RuTiCrSi were investigated using the Kohn-Sham DFT (KS-DFT) calculations within the generalized gradient approach (GGA), the modified version of the exchange potential introduced by Becke and Johnson in addition to the GGA (mBJ-GGA), and Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional. The ground-state equilibrium energy reveals that the ferromagnetic with type 2 structure is the more stable. The RuTiCrSi is energetically, mechanically, and dynamically stable. The calculated self-consistent total magnetic moment is 2 μB and agrees well with the Slater-Pauling rule of $��M_t�=�\left(�Z_t�-�24�\right)�$. The electronic structure results from mBJ-GGA and HSE06 functionals show a half-metallic behavior. A high Curie temperature is obtained using the mean-field approximation. The thermoelectric response was calculated using the semi-classical Boltzmann transport equation under constant relaxation time. The maximum value of Seebeck coefficient is observed at the ambient temperature of $��741��\mathrm{\mu V}��K^{�-�1�}�$. It was also observed that the power factor increases significantly as temperature rises. Therefore, the new EQHA RuTiCrSi seems to be a potential candidate for spintronic thermoelectric applications.