Pub Date : 2026-03-01Epub Date: 2025-11-14DOI: 10.1016/j.chemphys.2025.113029
I. Armenise , F. Esposito , G. Bonasia , G. Micca Longo , S. Longo
The application of multilayer feedforward backpropagation neural network is investigated for the implementation of state-to-state rate coefficients in a chemically reacting air system, which includes excited vibrational states and radicals. An oxygen dissociation reaction is chosen as a case study because of its importance, and also to compare it with a high-end traditional fit in terms of various performances in isolation and within a kinetic model. Different network architectures are experimented and compared, by varying the number of layers and neurons. The indications provided are relevant for practical use of different data implementation techniques in complex kinetic models.
{"title":"Evaluation of neural network in multivariate interpolation of rate coefficients in air kinetics","authors":"I. Armenise , F. Esposito , G. Bonasia , G. Micca Longo , S. Longo","doi":"10.1016/j.chemphys.2025.113029","DOIUrl":"10.1016/j.chemphys.2025.113029","url":null,"abstract":"<div><div>The application of multilayer feedforward backpropagation neural network is investigated for the implementation of state-to-state rate coefficients in a chemically reacting air system, which includes excited vibrational states and radicals. An oxygen dissociation reaction is chosen as a case study because of its importance, and also to compare it with a high-end traditional fit in terms of various performances in isolation and within a kinetic model. Different network architectures are experimented and compared, by varying the number of layers and neurons. The indications provided are relevant for practical use of different data implementation techniques in complex kinetic models.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113029"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-10-19DOI: 10.1016/j.chemphys.2025.112975
Attaur Rahman , Muhammad Haneef , Bin Amin
This research work investigates the structural, elastic and mechanical, electronic, optical, acoustic, and thermal properties of the cubic, lead-free double perovskites Cs₂KAlCl₆, Cs₂KAlBr₆, and Cs₂KAlI₆. The Full-potential linearized augmented plane wave (FP-LAPW) formulism based on density functional theory (DFT) is employed using WIEN2k simulation code. These perovskites strongly fulfill the Gold-Schmidt tolerance (tG) and octahedral (μo) factor conditions. The negative values of formation enthalpy (Hf) demonstrate their thermodynamic stability. However, the Born’s stability criteria, the elastic and mechanical features, confirms its elastic and mechanical stability. The Cs2KAlCl6 and Cs2KAlBr6 are ductile, while Cs2KAlI6 is brittle, and all the three halide double perovskites exhibit anisotropic behavior, as indicated by their Pugh's & Poisson ratios, Cauchy-pressure and anisotropic factors. The acoustic behaviors of these compounds are explored through sound velocities estimations. Thermal performances are analyzed with Debye & melting temperature, and thermal expansion coefficient. It is evident from the electronic properties, these perovskites are direct band semiconductors having band gap values 4.38, 3.04, and 1.71 eV for Cs2KAlCl6, Cs2KAlBr6 and Cs2KAlI6 respectively. A stepwise tuning of the band gap is observed, driven by the increase in ionic size moving down the halogen group from Cl to Br to I, which gradually reduces the band gap. The threshold values of optical parameters for Cs2KAlCl6/(Cs2KAlBr6 and Cs2KAlI6) start from ultraviolet/(visible light) range and both go on maximum in the ultraviolet region. Hence, offer an open range to be used in optoelectronic and photovoltaic renewable energy applications. Moreover, the alignment of valence and conduction band edge potentials relative to the standard redox potentials of water splitting make these compounds a promising choice for hydrogen production through photocatalysis.
{"title":"Cs2KAlY6 (Y = Cl, Br, I): A lead-free double perovskites for optoelectronic and photocatalytic applications","authors":"Attaur Rahman , Muhammad Haneef , Bin Amin","doi":"10.1016/j.chemphys.2025.112975","DOIUrl":"10.1016/j.chemphys.2025.112975","url":null,"abstract":"<div><div>This research work investigates the structural, elastic and mechanical, electronic, optical, acoustic, and thermal properties of the cubic, lead-free double perovskites Cs₂KAlCl₆, Cs₂KAlBr₆, and Cs₂KAlI₆. The Full-potential linearized augmented plane wave (FP-LAPW) formulism based on density functional theory (DFT) is employed using WIEN2k simulation code. These perovskites strongly fulfill the Gold-Schmidt tolerance (t<sub>G</sub>) and octahedral (μ<sub>o</sub>) factor conditions. The negative values of formation enthalpy (<span><math><mo>∆</mo></math></span>H<sub>f</sub>) demonstrate their thermodynamic stability. However, the Born’s stability criteria, the elastic and mechanical features, confirms its elastic and mechanical stability. The Cs<sub>2</sub>KAlCl<sub>6</sub> and Cs<sub>2</sub>KAlBr<sub>6</sub> are ductile, while Cs<sub>2</sub>KAlI<sub>6</sub> is brittle, and all the three halide double perovskites exhibit anisotropic behavior, as indicated by their Pugh's & Poisson ratios, Cauchy-pressure and anisotropic factors. The acoustic behaviors of these compounds are explored through sound velocities estimations. Thermal performances are analyzed with Debye & melting temperature, and thermal expansion coefficient. It is evident from the electronic properties, these perovskites are direct band semiconductors having band gap values 4.38, 3.04, and 1.71 eV for Cs<sub>2</sub>KAlCl<sub>6</sub>, Cs<sub>2</sub>KAlBr<sub>6</sub> and Cs<sub>2</sub>KAlI<sub>6</sub> respectively. A stepwise tuning of the band gap is observed, driven by the increase in ionic size moving down the halogen group from Cl to Br to I, which gradually reduces the band gap. The threshold values of optical parameters for Cs<sub>2</sub>KAlCl<sub>6</sub>/(Cs<sub>2</sub>KAlBr<sub>6</sub> and Cs<sub>2</sub>KAlI<sub>6</sub>) start from ultraviolet/(visible light) range and both go on maximum in the ultraviolet region. Hence, offer an open range to be used in optoelectronic and photovoltaic renewable energy applications. Moreover, the alignment of valence and conduction band edge potentials relative to the standard redox potentials of water splitting make these compounds a promising choice for hydrogen production through photocatalysis.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112975"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145340412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-10-30DOI: 10.1016/j.chemphys.2025.112999
Qiuhui Zhao , Yaqi Jing , Jiale Zhang , Jiadan Xue , Jianjun Liu , Jianyuan Qin , Zhi Hong , Yong Du
Isoniazid (INH), a frontline anti-tuberculosis drug, faces rising resistance and hepatotoxicity, motivating crystal-engineering approaches. The INH-4-hydroxybenzoic acid (INH-HBA) cocrystal shows multiple polymorphs, its hydrate exists in two forms whose lattice water markedly alters hydrogen-bond topology and molecular packing. We combined terahertz time-domain spectroscopy (THz-TDS) and FT-Raman spectroscopy with periodic solid-state DFT and potential energy distribution (PED) analysis to assign vibrational modes and link spectral features to structural motifs. Hirshfeld surface analysis indicates form I is dominated by multi-directional OH...N contacts and an NH...O synthon that yields parallel layered packing. By contrast, form II uses lattice water to bridge OH...O/NH...O interactions and weak CH...O contacts, producing a cross-stacked three-dimensional network lacking dimers. Observed spectral differences are attributed to these distinct intermolecular interactions and associated vibrations. By integrating experimental and theoretical data, this study provides spectroscopic-structural insights into INH-HBA hydrate polymorphism, offering a foundation for pharmaceutical cocrystal identification and design.
{"title":"Polymorphic behavior in isoniazid-4-hydroxybenzoic acid hydrated cocrystals: A combined terahertz, Raman vibrational spectroscopy, and DFT analysis","authors":"Qiuhui Zhao , Yaqi Jing , Jiale Zhang , Jiadan Xue , Jianjun Liu , Jianyuan Qin , Zhi Hong , Yong Du","doi":"10.1016/j.chemphys.2025.112999","DOIUrl":"10.1016/j.chemphys.2025.112999","url":null,"abstract":"<div><div>Isoniazid (INH), a frontline anti-tuberculosis drug, faces rising resistance and hepatotoxicity, motivating crystal-engineering approaches. The INH-4-hydroxybenzoic acid (INH-HBA) cocrystal shows multiple polymorphs, its hydrate exists in two forms whose lattice water markedly alters hydrogen-bond topology and molecular packing. We combined terahertz time-domain spectroscopy (THz-TDS) and FT-Raman spectroscopy with periodic solid-state DFT and potential energy distribution (PED) analysis to assign vibrational modes and link spectral features to structural motifs. Hirshfeld surface analysis indicates form I is dominated by multi-directional O<img>H...N contacts and an <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow></mrow></math></span> N<img>H...O synthon that yields parallel layered packing. By contrast, form II uses lattice water to bridge O<img>H...O/N<img>H...O interactions and weak C<img>H...O contacts, producing a cross-stacked three-dimensional network lacking <span><math><mrow><msubsup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mrow><mo>(</mo><mn>8</mn><mo>)</mo></mrow></mrow></math></span> dimers. Observed spectral differences are attributed to these distinct intermolecular interactions and associated vibrations. By integrating experimental and theoretical data, this study provides spectroscopic-structural insights into INH-HBA hydrate polymorphism, offering a foundation for pharmaceutical cocrystal identification and design.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112999"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-04DOI: 10.1016/j.chemphys.2025.113013
Raj Kumar Khan , B. Shivaranjini , S. Umadevi , R. Pratibha
Binary mixtures of two liquid crystals, one composed of chiral rod-like (R) and the other of achiral bent-core (BC) molecules, were investigated in order to obtain stable long range blue phases (BPs). While highly chiral BPs were found to be enhanced, the chiral nematic and chiral smectic C⁎ phases were suppressed and a long range non-chiral smectic A phase induced. Another interesting offshoot was the formation of a reentrant isotropic phase which has not been observed earlier in such systems. The results have been interpreted based on self-assembly of the R and BC molecules and the interplay of molecular chirality of the R molecules and conformation chirality of the BC molecules. The study demonstrates how phase behaviour and chirality in binary mixtures are closely connected with the specific molecular structures of the components and that a proper choice is essential for the design of new chiral materials for technological applications.
{"title":"Reentrant isotropic phase and enhanced blue phases in mixtures of chiral calamitic and achiral bent-core molecules","authors":"Raj Kumar Khan , B. Shivaranjini , S. Umadevi , R. Pratibha","doi":"10.1016/j.chemphys.2025.113013","DOIUrl":"10.1016/j.chemphys.2025.113013","url":null,"abstract":"<div><div>Binary mixtures of two liquid crystals, one composed of chiral rod-like (R) and the other of achiral bent-core (BC) molecules, were investigated in order to obtain stable long range blue phases (BPs). While highly chiral BPs were found to be enhanced, the chiral nematic and chiral smectic C<sup>⁎</sup> phases were suppressed and a long range non-chiral smectic A phase induced. Another interesting offshoot was the formation of a reentrant isotropic phase which has not been observed earlier in such systems. The results have been interpreted based on self-assembly of the R and BC molecules and the interplay of molecular chirality of the R molecules and conformation chirality of the BC molecules. The study demonstrates how phase behaviour and chirality in binary mixtures are closely connected with the specific molecular structures of the components and that a proper choice is essential for the design of new chiral materials for technological applications.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113013"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NiTe nanorods with varying levels of Molybdenum substitution were grown by a facile hydrothermal process, and their performance as electrocatalysts for hydrogen evolution reaction (HER) was evaluated. The 5% Mo-substituted NiTe was found to have the best performance as HER electrocatalyst with the lowest overpotential among pristine and substituted NiTe. Density functional theory studies further corroborate our experimental findings, showing that an optimum substitution of Mo in NiTe enhances the electrocatalytic property of NiTe. Our findings shed light on the factors determining the optimum substitution levels in electrocatalysts based on transition metal dichalcogenides.
{"title":"Enhanced electrocatalytic activity of optimally Mo-substituted NiTe2 nanorods for hydrogen evolution","authors":"Joyal Sunny , Karuna Sharma , Poonam Moar , Imtiaz Ahmed , Krishna Kanta Haldar , Krishnakanta Mondal , Sourabh Barua","doi":"10.1016/j.chemphys.2025.113018","DOIUrl":"10.1016/j.chemphys.2025.113018","url":null,"abstract":"<div><div>NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> nanorods with varying levels of Molybdenum substitution were grown by a facile hydrothermal process, and their performance as electrocatalysts for hydrogen evolution reaction (HER) was evaluated. The 5% Mo-substituted NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> was found to have the best performance as HER electrocatalyst with the lowest overpotential among pristine and substituted NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Density functional theory studies further corroborate our experimental findings, showing that an optimum substitution of Mo in NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> enhances the electrocatalytic property of NiTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Our findings shed light on the factors determining the optimum substitution levels in electrocatalysts based on transition metal dichalcogenides.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113018"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-15DOI: 10.1016/j.chemphys.2025.113026
Yanqiao Dong , Junfang Liu
To enhance the performance of bentonite-based barrier systems under heavy metal contamination, this study introduced corn straw biochar as an adsorptive amendment into polymer-modified calcium bentonite, successfully developing a polymer-modified calcium bentonite-biochar composite barrier material (PB8@C8). Through systematic evaluation of compressive strength, permeability coefficient, swell index, and adsorption performance, the optimal biochar content was determined to be 8 %. At this ratio, the material exhibited significant improvements in permeability coefficient, swell index, and adsorption capacity. Although the compressive strength slightly decreased, it still met the engineering requirement of 103.4 kPa. Microstructural characterization techniques such as XRD, SEM, FTIR, and BET confirmed the successful incorporation of biochar into the modified calcium bentonite, introducing abundant hydroxyl and carboxyl functional groups as well as a larger specific surface area, thereby enhancing the adsorption performance. Analysis of the Pb2+ adsorption behavior indicated that the adsorption process of PB8@C8 better conformed to the pseudo-second-order kinetic model and the Langmuir isotherm model, suggesting monolayer chemical adsorption as the dominant mechanism. Under the conditions of pH = 6, an adsorbent dosage of 0.25 g, and an initial Pb2+ concentration of 500 mg/L, the adsorption capacity of PB8@C8 for Pb2+ reached 195.98 mg/g.
{"title":"Adsorption and resistance properties of Pb2+ by modified calcium bentonite @ biochar composite barrier","authors":"Yanqiao Dong , Junfang Liu","doi":"10.1016/j.chemphys.2025.113026","DOIUrl":"10.1016/j.chemphys.2025.113026","url":null,"abstract":"<div><div>To enhance the performance of bentonite-based barrier systems under heavy metal contamination, this study introduced corn straw biochar as an adsorptive amendment into polymer-modified calcium bentonite, successfully developing a polymer-modified calcium bentonite-biochar composite barrier material (PB8@C8). Through systematic evaluation of compressive strength, permeability coefficient, swell index, and adsorption performance, the optimal biochar content was determined to be 8 %. At this ratio, the material exhibited significant improvements in permeability coefficient, swell index, and adsorption capacity. Although the compressive strength slightly decreased, it still met the engineering requirement of 103.4 kPa. Microstructural characterization techniques such as XRD, SEM, FTIR, and BET confirmed the successful incorporation of biochar into the modified calcium bentonite, introducing abundant hydroxyl and carboxyl functional groups as well as a larger specific surface area, thereby enhancing the adsorption performance. Analysis of the Pb<sup>2+</sup> adsorption behavior indicated that the adsorption process of PB8@C8 better conformed to the pseudo-second-order kinetic model and the Langmuir isotherm model, suggesting monolayer chemical adsorption as the dominant mechanism. Under the conditions of pH = 6, an adsorbent dosage of 0.25 g, and an initial Pb<sup>2+</sup> concentration of 500 mg/L, the adsorption capacity of PB8@C8 for Pb<sup>2+</sup> reached 195.98 mg/g.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113026"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-10-25DOI: 10.1016/j.chemphys.2025.112992
Maria Akhtar , Sharmin Akhter Maya , Md. Rafikul Islam , Md. Masiur Rahaman , Md Abdul Goni , Dileep Kumar , Md. Anamul Hoque , Mahbub Kabir , Ajamaluddin Malik
This study investigates the self-assembly of cetyltrimethylammonium bromide (CTAB) with sodium alginate (SA) in presence of anionic and nonionic hydrotropes (HYDTs) using conductometric technique. The research focused on determining critical micelle concentration (CMC) and degree of micelle ionization (α) of the CTAB + SA mixture by analyzing conductivity versus CTAB concentration plots. Results indicated that introduction of HYDTs significantly impeded micelle formation compared to aqueous medium. The CMC values also displayed a clear dependency on temperature variation. Notably, spontaneous micelle formation is confirmed by the negative Gibbs free energy () values across all solvents examined, suggesting favorable thermodynamic conditions for micellization. Additionally, magnitudes of enthalpy () and entropy changes () provided significant insights into underlying interaction forces, indicating that hydrophobic and electrostatic interactions play vital roles in the self-assembly process. These findings influence a deeper understanding of surfactant behavior in complex systems and may have expressive implications for industrial formulations, markedly in drug delivery and pharmaceutical design.
{"title":"Effects of hydrotropes and temperature on interactions between sodium alginate and cetyltrimethylammonium bromide surfactant: An experimental and theoretical study","authors":"Maria Akhtar , Sharmin Akhter Maya , Md. Rafikul Islam , Md. Masiur Rahaman , Md Abdul Goni , Dileep Kumar , Md. Anamul Hoque , Mahbub Kabir , Ajamaluddin Malik","doi":"10.1016/j.chemphys.2025.112992","DOIUrl":"10.1016/j.chemphys.2025.112992","url":null,"abstract":"<div><div>This study investigates the self-assembly of cetyltrimethylammonium bromide (CTAB) with sodium alginate (SA) in presence of anionic and nonionic hydrotropes (HYDTs) using conductometric technique. The research focused on determining critical micelle concentration (<em>CMC</em>) and degree of micelle ionization (<em>α</em>) of the CTAB + SA mixture by analyzing conductivity versus CTAB concentration plots. Results indicated that introduction of HYDTs significantly impeded micelle formation compared to aqueous medium. The <em>CMC</em> values also displayed a clear dependency on temperature variation. Notably, spontaneous micelle formation is confirmed by the negative Gibbs free energy (<span><math><mrow><msubsup><mi>ΔG</mi><mi>m</mi><mn>0</mn></msubsup></mrow></math></span>) values across all solvents examined, suggesting favorable thermodynamic conditions for micellization. Additionally, magnitudes of enthalpy (<span><math><mrow><msubsup><mi>ΔH</mi><mi>m</mi><mn>0</mn></msubsup></mrow></math></span>) and entropy changes (<span><math><mrow><msubsup><mi>ΔS</mi><mi>m</mi><mn>0</mn></msubsup></mrow></math></span>) provided significant insights into underlying interaction forces, indicating that hydrophobic and electrostatic interactions play vital roles in the self-assembly process. These findings influence a deeper understanding of surfactant behavior in complex systems and may have expressive implications for industrial formulations, markedly in drug delivery and pharmaceutical design.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112992"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-10DOI: 10.1016/j.chemphys.2025.113019
K.L. Ngai , Yanhui Zhang , Li-Min Wang , S. Capaccioli
In many studies of the dynamics of glass-forming materials pressure P and temperature T were varied while keeping the structural α-relaxation time τα(T,P) constant. Found generally by experiments and simulations is the frequency dispersion of the α-relaxation, or the exponent βK of its Kohlrausch-Williams-Watts correlation function, remains the same. Moreover, the Johari-Goldstein (JG) β-relaxation time τβ(T,P) is also constant. This remarkable and ubiquitous property of invariance of τα(T,P), βK(T,P), and τβ(T,P) collectively to varying P and T at constant τα(T,P) originates from the inseparable connection between the JGβ relaxation and the α-relaxation as predicted by the Coupling Model. Not considered before in this property is the caged dynamics, which has all molecules confined within cages via the intermolecular potential, and it is the precursor of the JGβ relaxation. The caged dynamics is strongly coupled to the JGβ and α relaxations as indicated by its decay and eventual termination by the onset of the JGβ relaxation, and its change of temperature dependence on crossing the glass transition temperatures Tgβ and Tgα of the JGβ and α relaxations. The strong connections of the caged dynamics to the JGβ and α relaxations suggest it is also invariant to changes of P and T at constant τα(T,P). Collected in this paper are data of caged dynamics from neutron scattering and dielectric relaxation experiments, and molecular dynamics simulations performed at different combinations of P and T at constant τα(T,P). The results clearly verify the invariance of the caged dynamics collectively with τα(T,P), βK(T,P), and τβ(T,P) to variations of P and T at constant τα(T,P). This co-invariance property extended to include the caged dynamics is expected to have repercussion on current research of the dynamics and thermodynamics of glass-forming materials.
{"title":"Co-invariance of caged dynamics with α and β relaxation to variation of temperature and pressure with the α-relaxation time kept constant","authors":"K.L. Ngai , Yanhui Zhang , Li-Min Wang , S. Capaccioli","doi":"10.1016/j.chemphys.2025.113019","DOIUrl":"10.1016/j.chemphys.2025.113019","url":null,"abstract":"<div><div>In many studies of the dynamics of glass-forming materials pressure <em>P</em> and temperature <em>T</em> were varied while keeping the structural α-relaxation time <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>) constant. Found generally by experiments and simulations is the frequency dispersion of the α-relaxation, or the exponent <em>β</em><sub><em>K</em></sub> of its Kohlrausch-Williams-Watts correlation function, remains the same. Moreover, the Johari-Goldstein (JG) <em>β</em>-relaxation time <em>τ</em><sub><em>β</em></sub>(<em>T,P</em>) is also constant. This remarkable and ubiquitous property of invariance of <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>), <em>β</em><sub><em>K</em></sub>(<em>T,P</em>), and <em>τ</em><sub><em>β</em></sub>(<em>T,P</em>) collectively to varying <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>) originates from the inseparable connection between the JG<em>β</em> relaxation and the α-relaxation as predicted by the Coupling Model. Not considered before in this property is the caged dynamics, which has all molecules confined within cages via the intermolecular potential, and it is the precursor of the JG<em>β</em> relaxation. The caged dynamics is strongly coupled to the JGβ and α relaxations as indicated by its decay and eventual termination by the onset of the JGβ relaxation, and its change of temperature dependence on crossing the glass transition temperatures <em>T</em><sub><em>gβ</em></sub> and <em>T</em><sub><em>gα</em></sub> of the JGβ and α relaxations. The strong connections of the caged dynamics to the JGβ and α relaxations suggest it is also invariant to changes of <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>). Collected in this paper are data of caged dynamics from neutron scattering and dielectric relaxation experiments, and molecular dynamics simulations performed at different combinations of <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>). The results clearly verify the invariance of the caged dynamics collectively with <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>), <em>β</em><sub><em>K</em></sub>(<em>T,P</em>), and <em>τ</em><sub><em>β</em></sub>(<em>T,P</em>) to variations of <em>P</em> and <em>T</em> at constant <em>τ</em><sub><em>α</em></sub>(<em>T,P</em>). This co-invariance property extended to include the caged dynamics is expected to have repercussion on current research of the dynamics and thermodynamics of glass-forming materials.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113019"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-07DOI: 10.1016/j.chemphys.2025.113015
Mohamed El Amine El Goutni , Hela Ferjani , Mohammed Batouche , Taieb Seddik
Vacancy-ordered double perovskites A₂TeX₆ (A = Cs, Rb; X = Cl, Br, I) are promising lead-free semiconductors for photocatalysis and photovoltaics. Using density functional theory (DFT) combined with experimental comparisons, we investigated their structural, electronic, and optical properties. Phonon dispersions and ab initio molecular dynamics (AIMD) simulations at 300 K confirm their dynamical stability, with energy fluctuations <0.1 eV and temperature oscillations within ±30 K. Calculated indirect band gaps range from 1.40 eV (Cs₂TeI₆) to 2.65 eV (Rb₂TeCl₆), in excellent agreement with reported experimental values (1.5–2.7 eV). Effective carrier masses are light (0.23–0.41 mₑ), supporting mobility ratios exceeding 102, favorable for charge transport. Density of states analysis indicates Te-p states dominate the valence band, while halide-p orbitals shape the conduction band. Optical spectra confirm strong absorption in the visible region, while band edge alignment indicates suitability for water oxidation and CO₂ reduction. These results demonstrate A₂TeX₆ compounds as stable, tunable, and environmentally benign candidates for next-generation energy conversion devices.
空位有序双钙钛矿A₂TeX₆（A = Cs, Rb; X = Cl, Br， I）是一种很有前途的用于光催化和光伏发电的无铅半导体材料。利用密度泛函理论（DFT）结合实验比较，研究了它们的结构、电子和光学性质。300 K下声子色散和从头算分子动力学（AIMD）模拟证实了它们的动力学稳定性，能量波动<；0.1 eV，温度振荡在±30 K内。计算的间接带隙范围从1.40 eV （Cs₂TeI₆）到2.65 eV （Rb₂TeCl₆），与报告的实验值（1.5-2.7 eV）非常吻合。有效载流子质量较轻（0.23-0.41 mₑ），迁移率超过102，有利于电荷输运。态密度分析表明Te-p态主导价带，而卤化物-p轨道主导导带。光谱证实了可见光区的强吸收，而带边缘排列表明适合水氧化和CO₂还原。这些结果证明了A₂TeX₆化合物是下一代能量转换装置的稳定、可调和环保的候选物。
{"title":"Tailoring solar photocatalysis and water oxidation in lead-free A₂TeX₆ (A = Cs, Rb; X = Cl, Br, I) perovskites via halide substitution","authors":"Mohamed El Amine El Goutni , Hela Ferjani , Mohammed Batouche , Taieb Seddik","doi":"10.1016/j.chemphys.2025.113015","DOIUrl":"10.1016/j.chemphys.2025.113015","url":null,"abstract":"<div><div>Vacancy-ordered double perovskites A₂TeX₆ (A = Cs, Rb; X = Cl, Br, I) are promising lead-free semiconductors for photocatalysis and photovoltaics. Using density functional theory (DFT) combined with experimental comparisons, we investigated their structural, electronic, and optical properties. Phonon dispersions and ab initio molecular dynamics (AIMD) simulations at 300 K confirm their dynamical stability, with energy fluctuations <0.1 eV and temperature oscillations within ±30 K. Calculated indirect band gaps range from 1.40 eV (Cs₂TeI₆) to 2.65 eV (Rb₂TeCl₆), in excellent agreement with reported experimental values (1.5–2.7 eV). Effective carrier masses are light (0.23–0.41 mₑ), supporting mobility ratios exceeding 10<sup>2</sup>, favorable for charge transport. Density of states analysis indicates Te-p states dominate the valence band, while halide-p orbitals shape the conduction band. Optical spectra confirm strong absorption in the visible region, while band edge alignment indicates suitability for water oxidation and CO₂ reduction. These results demonstrate A₂TeX₆ compounds as stable, tunable, and environmentally benign candidates for next-generation energy conversion devices.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 113015"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-03-01Epub Date: 2025-11-04DOI: 10.1016/j.chemphys.2025.112954
Damin Cao , Jiayi Zhao , Zhiyuan Yu , Shuo Chen
The precise manipulation of droplets takes key role in microfluidic chips, involving biological detection and chemical reactions. In the present paper, the dynamics of droplet impacting on an inclined hydrophilic-superhydrophobic surface are investigated experimentally and numerically. The processes of post-impact behaviors are captured by snapshots, suggesting that the bouncing direction can be well managed by maximal attachment distance of the droplet spreading in the hydrophilic region () and the inclined angle (). The forces between droplets and hydrophilic-superhydrophobic surface causing the unbalanced torque are studied via many-body dissipative particle dynamics (MDPD) method. Moreover, the theoretical models for predicting movement velocity and bouncing height are established through analyzing the competition between capillary force and gravity, showing good consistence to the experimental and numerical outcomes. The present work aims to provide the post-impact mechanism of droplets on heterogeneous surfaces, which is helpful to the corresponding applications.
{"title":"Dual-directional manipulation of droplet impacting on an inclined hydrophilic-superhydrophobic surface","authors":"Damin Cao , Jiayi Zhao , Zhiyuan Yu , Shuo Chen","doi":"10.1016/j.chemphys.2025.112954","DOIUrl":"10.1016/j.chemphys.2025.112954","url":null,"abstract":"<div><div>The precise manipulation of droplets takes key role in microfluidic chips, involving biological detection and chemical reactions. In the present paper, the dynamics of droplet impacting on an inclined hydrophilic-superhydrophobic surface are investigated experimentally and numerically. The processes of post-impact behaviors are captured by snapshots, suggesting that the bouncing direction can be well managed by maximal attachment distance of the droplet spreading in the hydrophilic region (<span><math><mi>e</mi></math></span>) and the inclined angle (<span><math><mi>θ</mi></math></span>). The forces between droplets and hydrophilic-superhydrophobic surface causing the unbalanced torque are studied via many-body dissipative particle dynamics (MDPD) method. Moreover, the theoretical models for predicting movement velocity and bouncing height are established through analyzing the competition between capillary force and gravity, showing good consistence to the experimental and numerical outcomes. The present work aims to provide the post-impact mechanism of droplets on heterogeneous surfaces, which is helpful to the corresponding applications.</div></div>","PeriodicalId":272,"journal":{"name":"Chemical Physics","volume":"602 ","pages":"Article 112954"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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