Perfect Surface Research Articles

Promoting effect of CO2 on NiCr oxidation: Atomistic origins based on first principles.

The adsorption and dissociation of CO2 on both perfect and oxygen-deficient α-Cr2O3 (0001) surfaces, alongside the subsequent incorporation of the resulting C into the oxide lattice and its impact on oxide growth, are investigated using first-principles calculations. Our findings reveal that oxygen vacancies significantly enhance CO2 adsorption and promote its stepwise decomposition into C and O atoms. The resulting C can spontaneously dissolve into the oxide lattice through the oxygen vacancies. The presence of bulk dissolved C in the Cr2O3 lattice substantially enhances the formation, migration, and clustering of oxygen vacancies in the bulk. These results provide an atomic-level understanding of how CO2 accelerates the oxidation of chromia-forming alloys, offering microscopic insights for controlling oxide growth and mitigating oxidation-induced degradation of high-temperature alloys.

Interaction of H2S with perfect and O-covered Pd(100) surface: A first-principles study

Using density functional theory (DFT) calculations, we investigated the dissociative mechanism of H2S adsorption and its dissociation on both clean and oxygen covered Pd (100) surface. For adsorption mechanism, the site preference was considered for H2S and HS monomers on both surfaces. The results suggest that H2S is energetically adsorbed on high symmetry sites, particularly the hollow site, on clean surface and top site on O-covered Pd (100) surface. Chemisorption of HS is stronger than H2S at the favorable hollow site on clean surface and O-covered surface. The energy barriers for S–H bond-breaking during the first H2S dehydrogenation are 0.35, 0.07, 0.32, and 0.16 eV, while for second dehydrogenation are 0.32 and 0.30 eV, respectively. On the oxygen-covered surface, the H2S adsorption site transitions from bridge to the top site and their energy barrier for first-order decomposition is 0.05 eV, significantly lesser than that observed on a clean surface. To examine more, the electronic densities of states as well as d-band center model were used to characterize the interaction of adsorbed H2S with the surfaces. Overall, our findings show that H2S decomposition on these surfaces is exothermic and relatively easy, but the presence of surface oxygen hinders the breaking process of H–S bond due to kinetic and thermodynamic factors.

Catalytic properties of trivalent rare-earth oxides with intrinsic surface oxygen vacancy

Oxygen vacancy (Ov) is an anionic defect widely existed in metal oxide lattice, as exemplified by CeO2, TiO2, and ZnO. As Ov can modify the band structure of solid, it improves the physicochemical properties such as the semiconducting performance and catalytic behaviours. We report here a new type of Ov as an intrinsic part of a perfect crystalline surface. Such non-defect Ov stems from the irregular hexagonal sawtooth-shaped structure in the (111) plane of trivalent rare earth oxides (RE2O3). The materials with such intrinsic Ov structure exhibit excellent performance in ammonia decomposition reaction with surface Ru active sites. Extremely high H2 formation rate has been achieved at ~1 wt% of Ru loading over Sm2O3, Y2O3 and Gd2O3 surface, which is 1.5–20 times higher than reported values in the literature. The discovery of intrinsic Ov suggests great potentials of applying RE oxides in heterogeneous catalysis and surface chemistry.

A DFT investigation on surface and defect modulation of the Co3O4 catalyst for efficient oxygen evolution reaction

The electrolysis of a water for hydrogen production is a promising way to produce clean energy, but the sluggish oxygen evolution reaction (OER) limits the overall efficiency of water electrolysis. In this work, we investigated the water oxidation pathways on the perfect and defect Co3O4(111) surfaces by using density functional theory (DFT) calculations. We found that for the perfect surface the free energy barrier of the potential determining step (PDS) in the adsorbate evolution mechanism (AEM) of water is lower than that in the lattice oxygen mechanism (LOM). For the defect surfaces, cobalt vacancies are more easily formed than oxygen vacancies. The Co vacancy promotes the formation of *OH, changes the PDS of the LOM and AEM, and reduces the free energy barrier of both PDS. The PDS of the LOM pathway on the VCo2Co3O4(111) surface is the coupling step of the O adatom and lattice oxygen, which promotes the LOM process. Different from the OER mechanism on the perfect surface and the defect surface with Co vacancy, the LOM is perferred to occur on the defect surface with O vacancy. This work may provide new insight into the relationship between the surface structure and OER activity surface of the Co3O4 catalyst and help to design the efficient OER catalysts by surface and vacancy engineering.

The Comparison of Individual and Group Hybrid Telerehabilitation Methods in Women with Urinary Incontinence.

The aim is to compare the effects of the progressive training program (PTP), a new protocol, with two different hybrid telerehabilitation methods, on the parameters related to urinary incontinence in women with urinary incontinence. A total of 50 participants with stress or mixed urinary incontinence participated in this two-arm, parallel-group, randomized, non-inferiority trial. Individual hybrid training (IHT) or group hybrid training (GHT) was given to women for 8weeks. The Power, Endurance, Repetitions, Fast contractions, and Every Contraction Timed (PERFECT) scheme and surface electromyography were used to assess pelvic floor muscle function, whereas quality of life, exercise adherence, and symptoms were assessed by questionnaires and a 3-day bladder diary. An intention-to-treat analysis was performed. Linear mixed model analysis with the factors "time" and "group" was used to determine the effects of IHT and GHT. The primary outcome was changes in pelvic floor muscle function as evaluated using the PERFECT scheme and surface electromyography at the 4th and 8th weeks relative to baseline. No statistical difference was found between the groups except for "power" of the PERFECT scheme and "nocturnal urination frequency" (p > 0.05). The GHT showed significant improvement in P and nocturnal urination frequency at the end of the 8th week (p < 0.05). From baseline to week 8, the effect size for the P value was found to be small (Cohen's d = 0.33). Eightweeks of PTP did not lead to different results in incontinence-related parameters in either of the training methods. It may be better to conduct GHT in terms of implementing PTP in incontinence and training programs in terms of time, staff workload, and applicability.

Coexistence of Interacting Charge Density Waves in a Layered Semiconductor.

Coexisting orders are key features of strongly correlated materials and underlie many intriguing phenomena from unconventional superconductivity to topological orders. Here, we report the coexistence of two interacting charge-density-wave (CDW) orders in EuTe_{4}, a layered crystal that has drawn considerable attention owing to its anomalous thermal hysteresis and a semiconducting CDW state despite the absence of perfect Fermi surface nesting. By accessing unoccupied conduction bands with time- and angle-resolved photoemission measurements, we find that monolayers and bilayers of Te in the unit cell host different CDWs that are associated with distinct energy gaps. The two gaps display dichotomous evolutions following photoexcitation, where the larger bilayer CDW gap exhibits less renormalization and faster recovery. Surprisingly, the CDW in the Te monolayer displays an additional momentum-dependent gap renormalization that cannot be captured by density-functional theory calculations. This phenomenon is attributed to interlayer interactions between the two CDW orders, which account for the semiconducting nature of the equilibrium state. Our findings not only offer microscopic insights into the correlated ground state of EuTe_{4} but also provide a general nonequilibrium approach to understand coexisting, layer-dependent orders in a complex system.

First-principle investigation the initial oxidation of methane on Pd doped LaCo0.2Fe0.8O3-δ anode surfaces of solid oxide fuel cells

Initial oxidation of methane (CH4) is essential for subsequent oxidation reactions on anode surfaces of solid oxide fuel cells (SOFCs). Here first principle method was employed to investigate the initial oxidation mechanism of CH4 on Pd doped LaCo0.2Fe0.8O3-δ (LCF) anode. Results show that Pd-doping decreases formation energies of surface oxygen vacancy. The adsorption ability of CH4 molecules is also improved on perfect LCF surface by Pd-doping. Dissociation barriers of CH4 on LCF surfaces are greatly decreased with min value of 1.14 eV by Pd-doping and surface oxygen vacancy compared to those on perfect and defective LCF surfaces (min values of 1.76 and 1.34 eV, respectively). Results of Bader charges and bond lengths of CH4 (or CH3) and OH show that the initial oxidation of CH4 molecules is namely the oxidation of dissociated H atoms from CH4 molecules. And higher valences of surface metal atoms interacted with CH4 molecules mean the lower dissociation barriers of CH4 molecules.

Theoretical and Experimental Investigations of Identifying Bridge Damage Using Instantaneous Amplitude Squared Extracted from Vibration Responses of a Two-Axle Passing Vehicle

Identifying bridge damage using a movable test vehicle is highly regarded for its mobility, cost-effectiveness, and broad monitoring coverage. Previous studies have shown that the residual contact-point (CP) response between connected vehicles is free of the impact of vehicle self-vibrations and road roughness, making it particularly suitable for the indirect extraction of bridge modal properties. However, most experimental campaigns regarding contact-point (CP) responses focus on a single-axle testing vehicle within a non-moving state. This study aims to theoretically and experimentally identify bridge damage using the instantaneous amplitude squared (IAS) extracted from the residual CP response of a two-axle passing vehicle. First, the closed-form solution of the residual CP acceleration was derived for a two-axle vehicle interacting with a simply supported beam. The IAS index was constructed from the driving frequency of the residual CP acceleration. Then, numerical investigations using finite element simulation were conducted to validate using the IAS index for indirect bridge damage identification. The application scope of the approach under various vehicle speeds and road roughness grades was examined. Finally, a laboratory vehicle–bridge interaction system was tested to validate the approach. Numerical studies demonstrated that bridge damage could be directly determined by observing the IAS abnormalities, which were baseline-free. The IAS from the residual CP response outperformed the IAS from CP responses in identifying bridge damage. However, it was better to use the IAS when the vehicle speed was no greater than 2 m/s and the grade of the road surface roughness was not high. Laboratory tests showed that it was possible to identify bridge damage using the IAS extracted from the residual CP acceleration under perfect road surfaces. However, it fell short under rough road surfaces. Hence, further experiments are required to fully examine the capacity of the IAS for bridge damage identification in practical applications.

Effects of sulfur‐ and Fe‐deficient defects on the decomposition of hydrogen peroxide H2O2 on pyrite surface

AbstractThere is still a lack of research on the effect of the S and Fe vacancy on the adsorption mechanism of peroxide (H2O2) on the pyrite surface. In this work, the adsorption of H2O2 molecules on the perfect and defective pyrite surface is simulated based on density functional theory (DFT). The results indicated that the adsorption energy of H2O2 molecules on the S‐vacancy surface is relatively lower than that on the perfect surface and dissociative adsorption entirely occurs, while the adsorption behavior of H2O2 molecules on the S‐rich pyrite surface has not occurred. When the H2O2 molecules are adsorbed on the Fe‐rich pyrite surface, two products appear, one with two OH− species and the other with an H2O molecule and an O atom. The analysis of the transition state (TS) found that the dissociation of the H2O2 molecule producing two OH− species that bond with two Fe atoms is more likely to occur. In addition, based on the coordination chemistry, it is demonstrated that Fe atoms are more reactive around an S vacancy than on a perfect surface.

DFT insights into doping and oxygen vacancy effects on CO and CO₂ adsorptions over CuAl2O4 spinel surfaces

Introducing transition metals into CuAl2O4 spinel enhances catalyst stability and Cu sintering resistance in methanol steam reforming. Yet, the influence of doping on vacancy formation and the adsorption behaviors of CO2 (the primary product) and CO (the notorious byproduct) remains unclear. Herein, we employed DFT + U to investigate CO and CO2 adsorption on perfect, M-doped (Fe, Co, and Ni), and M-doped oxygen-deficient CuAl2O4 spinel (100) and (110) surfaces. We find that stronger CO adsorption on (100) than (110) surfaces across all M-doped surfaces, while CO2 adsorbs more stronger on (110) surfaces. The weakened CO adsorptions are observed on Fe and Ni-doped surfaces, demonstrating that doping plays a significant role in improving the resistance to CO poisoning. Co-doping promotes CO adsorption via a CO3-like structure on CuAl2O4(110) surface and boosts the CO oxidation. Furthermore, infrared spectroscopy simulation indicates that the vibrational frequencies for CO linear adsorption, formation of bent CO2- and CO3-like structures are within the ranges of 2042–2078, 1463–1566, and 1497–1816 cm−1, respectively. In addition, Ov on Ni-doped surfaces can significantly strengthen the CO2 adsorption by 0.6–1.3 eV, highlighting the doping and oxygen-defect engineering in enhancing the CO2 capture. This research uncovers the critical impact of metal doping and oxygen vacancies on CO and CO2 adsorptions over CuAl2O4 spinel catalyst, providing insights for developing catalysts with improved resistance to CO poisoning and enhanced CO oxidation which is vital for methanol steam reforming.

Regulating Surface-Passivator Binding Priority for Efficient Perovskite Light-Emitting Diodes.

Suppressing trap-assisted nonradiative losses through passivators is a prerequisite for efficient perovskite light-emitting diodes (PeLEDs). However, the complex bonding between passivators and perovskites severely suppresses the passivation process, which still lacks comprehensive understanding. Herein, the number, category, and degree of bonds between different functional groups and the perovskite are quantitatively assessed to study the passivation dynamics. Functional groups with high electrostatic potential and large steric hindrance prioritize strong bonding with organic cations and halides on the perfect surface, leading to suppressed coordination with bulky defects. By modulating the binding priorities and coordination capacity, hindrance from the intense interaction with perfect perovskite is significantly reduced, leading to a more direct passivation process. Consequently, the near-infrared PeLED without external light out-coupling demonstrates a record external quantum efficiency of 24.3% at a current density of 42mA cm-2. In addition, the device exhibits a record-level-cycle ON/OFF switching of 20000 and ultralong half-lifetime of 1126.3h under 5mA cm-2. An in-depth understanding of the passivators can offer new insights into the development of high-performance PeLEDs.

Quantum dots on the InAs(110) cleavage surface created by atom manipulation

Cryogenic scanning tunneling microscopy was employed in combination with density-functional theory calculations to explore quantum dots made of In adatoms on the InAs(110) surface. Each adatom adsorbs at a surface site coordinated by one cation and two anions, and transfers one electron to the substrate, creating an attractive quantum well for electrons at the surface. We used the scanning-probe tip to assemble the positively charged adatoms into precisely defined quantum dots exhibiting a bound state roughly 0.1 eV below the Fermi level at an intrinsic linewidth of only ∼4 meV, as revealed by scanning tunneling spectroscopy. For quantum-dot dimers, we observed the emergence of a bonding and an antibonding state with even and odd wave-function character, respectively, demonstrating the capability to engineer quasimolecular electronic states. InAs(110) constitutes a promising platform in this respect because highly perfect surfaces can be readily prepared by cleavage and charged adatoms can be generated by the scanning-probe tip. Published by the American Physical Society 2024

Computational demystification of iron carbonyls formation under syngas environment

Iron pentacarbonyl (IPC) gas forms upon the reaction of carbon monoxide with Fe containing metallic surfaces under gas reforming conditions. IPC formation can sometimes reach alarming levels that cause metal loss, pipeline thinning corrosion, catalyst poisoning, and contamination of sensitive industrial equipment. In this work, we demystify using multiscale computational modeling the mechanism of Iron pentacarbonyl formation: Density functional theory (DFT) is used to explore various catalytic reactions that involve a Fe adatom reacting with adsorbed carbon monoxide. Our calculated carbonyls desorption barriers on a perfect and clean Fe surface are too high to allow the carbonyls to form then desorb at temperatures <500 K at the rates reported experimentally. Most importantly, our calculations indicate that a high CO surface coverage, in addition to the presence of Fe adatoms, favors carbonyl formation and its desorption towards the flowing gas medium. Using insights extracted from ab initio molecular dynamics simulations, we propose that the most plausible IPC formation mechanism consists of: (1) on surface reactions of adsorbed CO molecules with an Fe adatom to form iron tricarbonyl (Fe(CO)3*) molecules; (2) an adsorbate assisted movement of iron tricarbonyl on top of the CO adlayer; and (3) the interaction of iron tricarbonyl with CO molecules from the gaseous medium eventually leading to iron adatom removal as Fe(CO)5 gas.

Ruthenium, rhodium decorated perfect and Te-vacancy MoTe2 monolayer for industrial hazardous gases detection and scavenging

With the rapid development of industry and soaring of the global economy, the atmospheric pollution and human poisoning problems turn to a harsh circumstance. Accurate online monitoring and scavenging of industrial hazardous gases have become a bottleneck in recent years. In this paper, the adsorption mechanism and electrical properties of Ruthenium, Rhodium decorated perfect and Te-vacancy MoTe2 monolayer towards hazardous gases (SO2, CO, NH3) were firstly explored based on density functional theory. Comparing the adsorption behavior differences between perfect surface MoTe2 and Te atom vacancy MoTe2 through the analysis of density of states differential charge density and molecular orbital theory. The results show that the dopant reduces the band gap and enhances the surface competence. In addition, the trapping ability of the metal-modified defective MoTe2 to hazardous gases is inferior to that of the perfect MoTe2, and both adsorption types are physico-chemical adsorption. Modified MoTe2 could obtain the ideal recovery time as a NH3 gas sensor. CO are more difficult to detach from the mixture’ surfaces, which is a good proof for the CO adsorbent. The data provides the basis for the design of metal particle decoration based MoTe2 nanomaterials employed in the detection and scavenging of hazardous gases.

Optimization of grinding process for hard and brittle materials based on damage evolution mechanism

Grinding damage of hard and brittle materials has a direct impact on part strength and subsequent polishing efficiency. Damage suppression is one of the key research issues in hard and brittle material processing. Due to the uncertain damage evolution law, there is still a lack of optimization methods for the multi-step grinding process under given damage constraints. In this paper, the extended finite element method is used to establish a model between the prefabricated crack depth and final crack depth, which reveals the influence of various existing subsurface damages on crack propagation. It is found that only when the prefabricated crack depth is close to the indentation crack depth on the perfect surface, the final crack depth will be affected to some extent. To optimize the grinding process to achieve low damage, a semi-empirical model for predicting grinding damage is proposed which is suitable for process optimization and does not rely on some difficult-to-obtain parameters. Finally, based on the damage evolution law and prediction model, the core content of this paper is proposed, that is, a multi-step grinding process optimization method with variable grinding depth. This method can minimize the damage while ensuring the same processing efficiency, the damage depth is reduced by 25 %. The effectiveness of the optimization method and the correctness of the damage evolution law are proved by experiments. This method is suitable for engineering applications and has practical significance for understanding the damage evolution mechanism, which is helpful for the suppression of grinding damage and the optimization of the grinding process.

Wideband close perfect meta surface absorber for solar photovoltaic and optical spectrum applications

The leading research challenge is to develop a meta-surface absorber design for optimal performance across ultraviolet, visible, and near-infrared wavelengths. In ongoing research, a meta-surface absorber is being introduced, designed to achieve near-perfect absorption of 99% across the 250–2500 nm UV–Vis-NIR spectrum for both Transverse electric (TE) and Transverse magnetic (TM) polarized waves. The aimed design features a symmetrical resonator pattern, resulting in a polarization-insensitive absorption response. Additionally, the absorption response demonstrates robustness when altering the geometric parameters of the meta-surface unit cell. Precise simulation and modelling of the proposed meta-surface absorber are achieved by Employing a Finite Difference Frequency Domain (FDFD) solver, coupled with the Finite Integration Technique (FIT) and a tetrahedral mesh component. Verification of absorption characteristics is conducted through three frameworks: impedance matching, interference, and an equivalent circuit model. The suggested meta-structure design exhibits a uniform absorption response, as determined through considerations of impedance matching, interference theory, and the equivalent circuit theory. The PCR value is significantly lower than recent studies, reinforcing that the proposed meta-surface primarily serves as an absorber, not a polarization converter. The absorption response of the suggested meta-structure design remains consistent across the range of electromagnetic wave polarization angles from 0 to 90 for both TE and TM waves. Furthermore, the absorption response of the proposed design demonstrates stability up to an incident angle of 70 for electromagnetic waves. The distribution of electric and magnetic fields, along with surface current density on the proposed design, validates the existence of localized, propagating, and cavity surface plasmon resonance. These collectively create anti-parallel current flow, leading to the absorption of incident EM waves. Furthermore, the suggested design achieves a solar energy thermal conversion efficiency of 99% across the operational spectrum at a working temperature of 573 K, substantiating its potential for use as a solar absorber. Thus, this study presents a meta-structure unit cell that addresses the challenge with near-perfect absorption, polarization independence, and angle robustness. Applications include photodetection, thermal mapping, solar harvesting, and photo-trapping.

N2O ADSORPTION OVER FLAT AND DEFECTIVE Cu (110) SURFACES: PURE DFT AND DFT+U STUDIES INCLUDING vdW FORCES

The adsorption of N2O on flat and defective Cu (110) surfaces has been studied using pure density functional theory (DFT) and DFT with Hubbard U, including van der Waals (vdW) corrections of the form vdW-DF. The calculations show that for GGA-PBE, as the exchange-correlation and vdW-DF functionals are considered, N2O molecule interacts very weakly with the flat Cu (110) surface, while the presence of the Cu-adatom results in better stability of adsorbed N2O compared to one on the perfect surface. Also, the inclusion of U parameter to PBE and vdW-DF functionals reduces the values of the adsorption energy relative to the standard PBE and vdW-DF functionals with or without spin-polarization. Finally, the analysis of the projected density of states shows a strong hybridization between the Cu-3d band and N-2p orbital. Our investigation suggests that the Cu (110) surface can serve as a catalytic medium that is able to adsorb the harmful N2O molecule.

Effect of single vacancy defects on two-dimensional &lt;i&gt;δ&lt;/i&gt;-InSe stability

The two-dimensional (2D) semiconductor material of InSe has received much attention due to its excellent electrical properties and moderate adjustable bandgap. The vacancy defects in the material affect not only the optical and electrical properties, but also the environmental stability. Compared with other phases in InSe materials, &lt;i&gt;δ&lt;/i&gt;-InSe has superior material properties, however, the effect of environment on this material stabilityhas not been reported. In this work, we systematically investigate the stability of 2D &lt;i&gt;δ&lt;/i&gt;-InSe material under oxygen environment based on density functional theory. The results are shown below. Firstly, in an oxygen environment, the perfect &lt;i&gt;δ&lt;/i&gt;-InSe surface exhibits good inertness and stability, for O&lt;sub&gt;2&lt;/sub&gt; molecules need to overcome an exceptionally high energy barrier of 1.827 eV from physical adsorption to chemical adsorption on its surface. Secondly, the presence of Se vacancies (V&lt;sub&gt;Se&lt;/sub&gt;) promotes the oxidation reaction of &lt;i&gt;δ&lt;/i&gt;-InSe, which only requires overcoming a low energy barrier of 0.044 eV. This suggests that the stability of &lt;i&gt;δ&lt;/i&gt;-InSe in an oxygen environment is significantly reduced because of the presence of V&lt;sub&gt;Se&lt;/sub&gt;. The O&lt;sub&gt;2&lt;/sub&gt; molecules oxidized &lt;i&gt;δ&lt;/i&gt;-InSe monolayer is beneficial to the dissociation and adsorption of H&lt;sub&gt;2&lt;/sub&gt;O molecules. Finally, the oxidation rate of &lt;i&gt;δ&lt;/i&gt;-InSe with In vacancies (V&lt;sub&gt;In&lt;/sub&gt;) is slower, with the adsorption energy and charge transfer involved in the physical adsorption of O&lt;sub&gt;2&lt;/sub&gt; molecules on the V&lt;sub&gt;In&lt;/sub&gt; surface being similar to those on a perfect surface. The oxidation process needs to overcome a higher energy barrier of 1.234 eV. The findings of this study will provide theoretical guidance for better understanding the oxidation behavior of single vacancy defects in monolayer &lt;i&gt;δ&lt;/i&gt;-InSe, and reference for experimental preparation of high-reliability 2D &lt;i&gt;δ&lt;/i&gt;-InSe devices.

Autonomous robotic polishing of free-form poly-surfaces: planning from scanning in realistic industrial setting

We propose a novel solution for generating robot tool paths to achieve uniform surface polishing of free-form poly-surfaces, addressing the limitations of imperfect surface reconstruction in real industrial settings and of abruptly varying curvatures. Existing approaches assume perfect 3D surface knowledge and overlook pieces with abrupt changes in principal curvatures, leading to unsatisfactory outcomes like non-smooth paths and incomplete coverage. Our research aims to develop an algorithm that adapts the polishing path for uniform coverage despite imperfect reconstruction or aggressive varying curvatures of the objects to be polished. Users can control the path points density, overlapping, edge proximity, and scanning direction. By segmenting the surface based on curvature similarity and connecting the separately computed trajectories, we minimize polishing time and achieve optimal polishing quality of free-form poly-surfaces in real industrial settings.

THE EXECUTION OF THE MULTILEVEL FAST MULTIPOLE ALGORITHM USING FOURIER ANALYSIS TO SOLVE PLANE WAVE SCATTERING FROM PERFECT ELECTRIC CONDUCTOR SURFACES

The multilevel fast multipole algorithm (MLFMA) is an algorithm employed to speed up the matrix-vector multiplication required to solve equations using an iterative method. In this algorithm, the Green's function is approximated by an expression that separates the receiver point from the source point. Each problem has a unique Green's function, which means derivations are required to get the approximation. As a result, although the algorithm is the same for all problems, each problem requires a new code. To solve these issues, the MLFMA is executed by approximating the Green's function using a Fourier series. The proposed approach is to finding the approximation is straightforward. In addition, the code will always be the same regardless of the problem. In this study, electromagnetic wave scattering from two- and three-dimensional perfect electric conductor surfaces was solved using the proposed approach, the conventional approach, and the method of moments. The results revealed that the suggested method is precise and faster compared to the method of moments and slightly slower than the MLFMA for a large number of unknowns.