Qawareer Fatima, Azhar Ali Haidry, Usaid Ahmad, Haiqian Zhang
{"title":"The Critical Role of Tilting Descriptors in Data-Driven Property Prediction of Orthorhombic Perovskites","authors":"Qawareer Fatima, Azhar Ali Haidry, Usaid Ahmad, Haiqian Zhang","doi":"10.1002/adts.70513","DOIUrl":"10.1002/adts.70513","url":null,"abstract":"<div>\u0000 \u0000 <p>Accurate prediction of the properties of all relevant polymorphs is necessary for rational design of stable, high-performance perovskite materials. While the discovery of cubic perovskites has been hastened by machine learning (ML), the orthorhombic (Pnma) phase needed for device performance at room temperature has been little studied due to its complicated structural distortions. This work addresses this gap by developing a specialized ML framework for orthorhombic ABX<sub>3</sub> halide perovskites. We assembled a curated dataset of 3000 Pnma structures and developed a set of 67 descriptors specifically describing octahedral tilting, anisotropic distortion, and electrical effects. A thorough benchmark of twelve algorithms revealed XGBoost to be the best model, yielding credible predictions for formation energy (test R2 = 0.939) and band gap (test R2 = 0.619). Interestingly, the recursive feature removal showed that a low-dimensional electronic subspace controls formation energy, while the prediction of the band gap requires a complicated interplay of structural and electronic features. In contrast, prediction of thermodynamic stability (energy above hull) remained a challenge, revealing the limitations of existing compositional descriptors. This work introduces a verified and interpretable pathway for high-throughput screening of orthorhombic perovskites and provides fundamental insight into the descriptor-property connections governing different perovskite polymorphs.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148717608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Polarization-Independent Dichroic Beam Splitter Using All-Dielectric Metasurface at Near-Infrared Wavelength","authors":"Chandan Kumar, Bhairov Kumar Bhowmik, Tanmay Bhowmik, Pranav Kumar Pandey, Makaraju Srinivasa Raju, Debabrata Sikdar, Gagan Kumar","doi":"10.1002/adts.70501","DOIUrl":"10.1002/adts.70501","url":null,"abstract":"<div>\u0000 \u0000 <p>In the modern era, metasurfaces have gained significant attention for their potential in light manipulation, including focusing, bending, blocking, and wavefront control, as well as designing ultra-thin optical components. Metasurfaces comprising high-index dielectric nanostructures have emerged as an inevitable platform for high-performance flat optical devices. Among these, a dichroic beam splitter is a crucial optical component that selectively reflects and transmits light based on the wavelength, enabling precise control over beam routing. In this work, we demonstrate a polarization- and angle-tolerant metasurface-based dichroic beam splitter that operates as a harmonic separator, efficiently separating the fundamental wavelength (1560 nm) and its second harmonic (780 nm) wavelength. Using a 2D array of gallium phosphide (GaP) cylindrical nanostructures, the proposed device exhibits high transmission at 1560 nm while simultaneously achieving near-unity reflection at 780 nm over a bandwidth of approximately 168 nm. This device finds application in fluorescence microscopy, multispectral imaging and advanced laser systems due to its precise spectral selectivity in the near-infrared regime. Beyond these applications, our result highlights a versatile design route to compact dichroic beam splitters that can replace conventional bulky optical devices, with promising prospects for on-chip photonics and portable optical elements.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148717715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Awais Jehangir, Yang Gao, Abid Iqbal, Siddig M. Elkhider, Syed Hashim Raza Bukhari, Ali S. Alzahrani, G. Murtaza, Shamim Khan
{"title":"Unveiling X2LaAuI6 Through First Principles Study: Photocatalytic, Optoelectronic, and Thermoelectric Properties","authors":"Muhammad Awais Jehangir, Yang Gao, Abid Iqbal, Siddig M. Elkhider, Syed Hashim Raza Bukhari, Ali S. Alzahrani, G. Murtaza, Shamim Khan","doi":"10.1002/adts.70502","DOIUrl":"10.1002/adts.70502","url":null,"abstract":"<div>\u0000 \u0000 <p>The advancement of materials science increasingly focuses on predicting novel and functional materials, often driven by rapid screening enabled through density functional theory calculations. The current work on structural, mechanical, optoelectronic, photocatalytic, and thermoelectric X<sub>2</sub>LaAuI<sub>6</sub> (X = K/Rb/Cs) were analyzed using DFT. Crystal structure stability was confirmed through the phonon dispersion, while optoelectronic and thermoelectric properties were investigated using TB-mBJ and SOC exchange-correlation potentials, revealing that these compounds X<sub>2</sub>LaAuI<sub>6</sub> (X = K/Rb/Cs) are indirect with an accurate value of 2.28, 2.23, and 2.23 eV, respectively. The ductile nature of these materials was confirmed by Poisson's ratio and Pugh's modulus. The prominent absorption peaks in the near-visible region underscore the suitability of these compounds for solar cells and optoelectronic devices. SLME calculations indicated efficiencies of up to 7.5%, further support their potential for photovoltaic applications. Thermoelectric calculations were assessed using semi-classical Boltzmann theory (SCBT) across the temperature range of 200–1000 K. The materials exhibited promising ZT metrics at 1000 K, with values of 0.88, 0.86, and 0.89 for X<sub>2</sub>LaAuI<sub>6</sub> (X = K/Rb/Cs), respectively. These findings highlight the potential of X<sub>2</sub>LaAuI<sub>6</sub> (X = K/Rb/Cs) compounds for applications in solar cells, thermoelectric devices, and photocatalysis.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148691008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Angle-Independent and Polarization-Insensitive Colored Daytime Radiative Cooler Design Based on Ultra-Broadband Metasurface Thermal Emitter","authors":"Vivek Kumar Gupta, Prince Gupta, Dheeraj Pratap, Satyendra Prakash Pal, Govind Dayal","doi":"10.1002/adts.70505","DOIUrl":"10.1002/adts.70505","url":null,"abstract":"<div>\u0000 \u0000 <p>We numerically demonstrate a broadband long-wave infrared (LWIR) absorber with near-zero visible–near-infrared (Vis–NIR) absorption, enabling daytime radiative cooling with colored display. The structure comprises two patterned black phosphorus (BP) resonator layers separated by a dielectric spacer and backed by an optically thick metallic reflector. Although BP inherently exhibits strong in-plane optical anisotropy, polarization- and angle-insensitive behavior is achieved through the fourfold rotational symmetry of the metasurface unit cell. Full-wave electromagnetic simulations show an average absorptance exceeding 98% across the LWIR (8–14 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>μ</mi>\u0000 <mi>m</mi>\u0000 </mrow>\u0000 <annotation>$mathrm{mu}mathrm{m}$</annotation>\u0000 </semantics></math>) for both transverse electric (TE) and transverse magnetic (TM) polarizations, with stable performance for incident angles up to <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mn>70</mn>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <annotation>$70^circ$</annotation>\u0000 </semantics></math>, while absorptance in the VIS–NIR range (0.4–2.5 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>μ</mi>\u0000 <mi>m</mi>\u0000 </mrow>\u0000 <annotation>$mathrm{mu}mathrm{m}$</annotation>\u0000 </semantics></math>) remains below 5.5%. Under realistic daytime conditions, the resulting spectral emissivity yields a maximum net cooling power of approximately 94 W <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>m</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 <annotation>${rm m}^{-2}$</annotation>\u0000 </semantics></math> and a steady-state temperature reduction of about 7.8<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow></mrow>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <annotation>$^{circ }{rm C}$</annotation>\u0000 </semantics></math> below ambient. Colorimetric analysis based on the CIE 1931 standard illuminant D65 confirms a warm-yellow reflected appearance, demonstrating stable color display alongside efficient radiative cooling. The proposed BP-based dual-layer metasurface thus offers a compact, polarization- and angle-insensitive, spectrally selective platform for infrared thermal management, daytime radiative cooling, and multifunctional photonic applications.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148691009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Machine Learning for Second- and Third-Harmonic Generation: Benchmarks, Challenges, and a Roadmap for Data-Driven Photonic Materials","authors":"Masoumeh Shokati Mojdehi, Ramin Khezri","doi":"10.1002/adts.70500","DOIUrl":"10.1002/adts.70500","url":null,"abstract":"<div>\u0000 \u0000 <p>Nonlinear optical (NLO) processes, particularly second- and third-harmonic generation (SHG and THG), are central to modern photonics, enabling frequency conversion, ultrafast signal processing, and nonlinear imaging technologies. The discovery and optimization of efficient NLO materials remain challenging due to the complex interplay between structural symmetry, electronic band structure, and higher-order light-matter interactions, as well as the high cost and limited scalability of conventional experimental and computational approaches. Machine learning (ML) is increasingly adopted as a complementary framework to accelerate the prediction, screening, and inverse design of nonlinear susceptibilities. However, existing efforts remain fragmented, often limited to χ<sup>(2)</sup>-dominated systems, constrained material classes, and non-standardized benchmarking practices, while higher-order nonlinearities such as χ<sup>(3)</sup> remain underexplored. In this review, ML methodologies applied to SHG and THG are critically synthesized, with emphasis on descriptor design, dataset construction, model architectures, performance evaluation, and uncertainty quantification. Key challenges, including data scarcity, dataset heterogeneity, limited transferability, and insufficient incorporation of physical constraints, are systematically analyzed. Benchmarking considerations are discussed, and a roadmap for physics-informed and uncertainty-aware ML frameworks is outlined to support reproducible and scalable discovery of advanced NLO materials.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148687998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengan Hong, Jian Qi, Jie Hu, Jin Qi, Yuliang Shen, Shuo Zhang, Jing Guo, Guo-Niu Zhu
{"title":"Simulation-Based Performance Analysis of Roadheader Picks Considering Environmental Characteristics and Motion Trajectories","authors":"Chengan Hong, Jian Qi, Jie Hu, Jin Qi, Yuliang Shen, Shuo Zhang, Jing Guo, Guo-Niu Zhu","doi":"10.1002/adts.202502257","DOIUrl":"10.1002/adts.202502257","url":null,"abstract":"<div>\u0000 \u0000 <p>Boom-type roadheaders face a trade-off between cutting efficiency and component degradation, requiring precise performance evaluation of picks. To address high tunneling experiment costs and limitations of conventional simulations in rock modeling and motion reproduction, a performance analysis framework is developed via co-simulation based on Multibody Dynamics and the Discrete Element Method. This framework integrates three methodological contributions: (1) a reusable parametric simulation platform is constructed to resolve the complex “environment-motion” coupling, realizing a parameter mapping method that accurately associates macroscopic rock properties and actual motion trajectories with simulation boundary conditions; (2) oriented toward the cost-effective cutting mode, this study evaluates the performance of picks under the typical “S-shaped” path, specifically assessing the rock-breaking rate, load strength, and wear rate; (3) a component decoupling strategy and motion path segmentation are implemented to systematically analyze 25 distinct performance indicators of picks. Consequently, utilizing the enhanced Latin Hypercube Sampling (LHS) and Partial Dependence Plots (PDP) to conduct batch simulations, this study rigorously investigates the performance evolution laws, degradation mechanisms, and key influencing factors across different cutting phases. This work provides a rigorous workflow for tunneling equipment optimization, especially for the development of high-fidelity digital twins.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148675250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wasif Abu Dujana, Md Saiduzzaman, Tasdid Bin Kabir, Tahani Mohammed Alrosaa, Reda A. Haggam, Raghad Radi Al Rasheed, Amani Mubarak Al-Farhan, Zakia Hassan Alhashem, Mohammed Albossed, Shima Sadaf, Mir Waqas Alam, Noureddine Elboughdiri
{"title":"Hydrogen Storage Properties of XFe3H8 Hydrides: A First-Principles Study","authors":"Wasif Abu Dujana, Md Saiduzzaman, Tasdid Bin Kabir, Tahani Mohammed Alrosaa, Reda A. Haggam, Raghad Radi Al Rasheed, Amani Mubarak Al-Farhan, Zakia Hassan Alhashem, Mohammed Albossed, Shima Sadaf, Mir Waqas Alam, Noureddine Elboughdiri","doi":"10.1002/adts.70490","DOIUrl":"10.1002/adts.70490","url":null,"abstract":"<div>\u0000 \u0000 <p>The current work provides the first-principles exploration of the XFe<sub>3</sub>H<sub>8</sub> (X = Li, Na, K, and Rb) perovskite hydrides series. The negative formation energies confirm the thermodynamic stability of the entire XFe<sub>3</sub>H<sub>8</sub> series. Electronic band structures and density of states (DOS) analyses reveal the metallic nature of all compounds for both GGA and HSE06 functionals. The dynamic stability is confirmed by the positive phonon curves. Elastic constants satisfy Born stability criteria, with mechanical analysis indicating that all four hydrides show ductile behavior that suggest potential use of the compounds in flexible devices. The XFe<sub>3</sub>H<sub>8</sub> (X = Li, Na, K, and Rb) hydrides' exhibit gravimetric H<sub>2</sub> storage capacities of 4.42, 4.06, 3.76, and 3.09 wt.%, respectively demonstrating that LiFe<sub>3</sub>H<sub>8</sub> provides the highest capacity and superior performance in the series. The resulting volumetric H<sub>2</sub> storage capacities are 207.92, 187.98, 167.09, and 156.11 gH<sub>2</sub>/L respectively for XFe<sub>3</sub>H<sub>8</sub> (X = Li, Na, K, and Rb) hydrides.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148687774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Iterative Sumudu Transform Technique for a Fractional Chemotactic Interaction Process of Cellular Slime Mold","authors":"Neha Kalyan, Sanjeev Ahuja, Amit Prakash","doi":"10.1002/adts.70503","DOIUrl":"10.1002/adts.70503","url":null,"abstract":"<div>\u0000 \u0000 <p>In this article, we employ a hybrid methodology, ISTT by combining the “Sumudu transform” and the “Gejji–Jafari iterative technique” to obtain an approximate series solution of the fractional nonlinear Keller–Segel equation. The method is applied to three examples with different sensitivity functions and the obtained solutions are presented through graphical visualizations. The obtained results are compared with those reported by existing methods. In addition, the convergence behavior of the proposed method is discussed through the consecutive errors. The results show that ISTT provides a simple iterative approach for obtaining approximate solutions of nonlinear coupled fractional differential equations.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148674996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exploring the Potential of CsGeI3 Photovoltaics: Simulation Based Investigation for Optimal Device Configuration and Efficiency","authors":"Roopam, Jyoteesh Malhotra, Jaya Madan, Rahul Pandey","doi":"10.1002/adts.70491","DOIUrl":"https://doi.org/10.1002/adts.70491","url":null,"abstract":"<div>\u0000 \u0000 <p>For generating lead-free photovoltaic devices, CsGeI<sub>3</sub> appears as a good alternative because they show significant benefits in terms of materials and also provides environmental compatibility. It focuses on increasing stability and removing toxicity from Perovskite solar cell (PSC) while introducing an inexpensive electron transport layer (ETL) material, n-TiO2. Subsequently, an intrinsic-CsGeI<sub>3</sub> absorber layer based on FTO/n-TiO<sub>2</sub>/i-CsGeI<sub>3</sub>/p-CsGeI<sub>3</sub>/Au is proposed, which is economical for solar cell production. For performance analysis and modeling, the SCAPS-1D simulator has been used. Therefore, an innovative solar-cell device based on inorganic material CsGeI<sub>3</sub> is implemented. Simulating with the <i>p</i>-type of CsGeI<sub>3</sub> doped hole transport layer (HTL) material, accomplishing optimal device configurations, yielding a power conversion efficiency (PCE) of 11.07%, along with short circuit current density (J<sub>sc</sub>) of 21.06 mA/cm<sup>2</sup>, a fill factor (FF) of 65.15%, and an open circuit voltage (V<sub>oc</sub>) of 0.81 volts for the configuration of FTO/n-TiO<sub>2</sub>/i-CsGeI<sub>3</sub>/p-CsGeI<sub>3</sub>/Au.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arslan Zulfiqar, Muhammad Saqib Arslan, Farooq Ahmad
{"title":"The Physical Origin of Ultralow Lattice Thermal Conductivity in Strongly Anharmonic Thermoelectric Materials Na2CdSe and Na2HgSe","authors":"Arslan Zulfiqar, Muhammad Saqib Arslan, Farooq Ahmad","doi":"10.1002/adts.70504","DOIUrl":"https://doi.org/10.1002/adts.70504","url":null,"abstract":"<div>\u0000 \u0000 <p>Extremely low lattice thermal conductivity is a decisive condition for the development of high-efficiency thermoelectric materials that can convert waste heat to electrical power. By means of first-principles calculations in conjunction with the Boltzmann transport theory, we have carried out a systematic study of structural and thermoelectric properties of Na<sub>2</sub>CdSe and Na<sub>2</sub>HgSe, especially focusing on their low lattice thermal conductivity and its origin. Besides the thermoelectric transport, the electronic and 3D mechanical properties have also been studied. Both compounds show extremely low room-temperature lattice thermal conductivity of 0.31 Wm<sup>−1</sup>K<sup>−1</sup> for Na<sub>2</sub>CdSe and 2.32 Wm<sup>−1</sup>K<sup>−1</sup> for Na<sub>2</sub>HgSe. Detailed studies of cumulative thermal conductivities, phonon mean free paths, Grüneisen parameter, group velocity, phonon lifetime, and scattering rates show that the ultralow thermal transport mainly originates from low phonon group velocities, short mean free paths, as well as small phonon lifetimes. HSE06 calculations show that Na<sub>2</sub>CdSe and Na<sub>2</sub>Hg Se possess direct bandgap of 0.32 and 0.67 eV, respectively. Both materials have excellent thermoelectric performance, exhibiting maximum ZT values of 1.62 for Na<sub>2</sub>CdSe and 1.23 for Na<sub>2</sub>HgSe at 460 and 800 K, respectively. These results demonstrate that Na<sub>2</sub>CdSe and Na<sub>2</sub>HgSe are promising for efficient thermoelectric energy conversion with intrinsically low lattice thermal conductivity.</p>\u0000 </div>","PeriodicalId":7219,"journal":{"name":"Advanced Theory and Simulations","volume":"9 8","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148617380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}