Surface Mapping Research Articles

A pilot scale test study with theoretical justification of reaction mechanism for the recovery of chromium(VI) based on solvent extraction using novel centrifugal extractors

As a strategic resource and hazardous substance, the purification and recovery of chromium(VI) from the aqueous phase have attracted attention. In this study, the centrifugal extractor was used to treat the leach liquor of sodium roasting chromite on a pilot scale. The extraction performance and equilibrium distribution of chromium in countercurrent extraction were investigated. Meanwhile, the scrubbing effect of impurities was carefully studied, and the stripping and regeneration effects of the organic phase were tested. Under the selected process parameters, the pilot scale test results, including extraction efficiency of chromium, scrubbing efficiency of impurities, and regeneration performance of the organic phase, were excellent. The qualified (NH4)2Cr2O7 and Cr2O3 products were prepared using the strip liquor, and several physical properties of the products were tested. In addition, the molecular electrostatic potential surface maps, HOMO-LUMO orbitals, Fukui functions, and single point energy of the molecules involved were calculated by Quantum Chemistry. The molecular electrostatic potential analysis, frontiers molecular orbital analysis, Fukui function analysis and interaction energy analysis were applied to investigate the mechanism of separation of chromic acid from impurities in the extraction system.

Atmosphere-aware photoclinometry for pixel-wise 3D topographic mapping of Mars

High-resolution topographic mapping is essential for scientific investigations and operational exploration of planets, such as Mars. Photoclinometry, which uses light scattered from a surface to reconstruct 3D topography, can retrieve subtle topographic details from monocular images. However, its performance is affected by the atmosphere of Mars, which alters surface reflectance mechanisms due to the scattering and absorption by aerosols. Therefore, specific treatments accounting for these atmospheric effects are needed to enable photoclinometric mapping of Mars. This paper presents a novel photoclinometric approach incorporating a radiative-transfer model of atmospheric scattering effects for pixel-wise 3D reconstruction of the Martian surface. The approach requires a high-resolution image, a corresponding coarse-resolution digital elevation model (DEM), and information of the optical depth as inputs. A radiative transfer model adapted to the Martian atmosphere is used to account for the atmospheric effects. The approach also allows directly adopting optical depth estimates from a global database (e.g., the Mars Climate Database). The approach was validated using different types of Mars orbiter images collected by cameras on-board the Mars Reconnaissance Orbiter and the Tianwen-1 Orbiter. The results indicate that the approach can achieve a geometric accuracy (in terms of root-mean-squared error (RMSE) of the elevation) of approximately 2 pixels of the image resolution and significantly enhances topographic details. In addition, we evaluated the approach using different settings for the optical depths and spatial resolutions of the input DEMs. The results show that overestimating the optical depth leads to overestimation of topographic amplitudes (e.g., deeper craters). On the other hand, underestimating the optical depth by the same amount as overestimation leads to a smaller increase in the RMSE. Moreover, coarsening the resolution of an input DEM increases the RMSE of the photoclinometric results. Nevertheless, photoclinometry improves both the RMSE and the resolution of the input DEM. This new approach serves as an effective means for applying photoclinometry for pixel-wise 3D topographic mapping of the Martian surface. This will facilitate exploitation of the large number of high-resolution monocular images of Mars in 3D topographic mapping of the planet.

Compactness of harmonic maps of surfaces with regular nodes

Compactness of harmonic maps of surfaces with regular nodes

CartoCell, a high-content pipeline for 3D image analysis, unveils cell morphology patterns in epithelia

Decades of research have not yet fully explained the mechanisms of epithelial self-organization and 3D packing. Single-cell analysis of large 3D epithelial libraries is crucial for understanding the assembly and function of whole tissues. Combining 3D epithelial imaging with advanced deep-learning segmentation methods is essential for enabling this high-content analysis. We introduce CartoCell, a deep-learning-based pipeline that uses small datasets to generate accurate labels for hundreds of whole 3D epithelial cysts. Our method detects the realistic morphology of epithelial cells and their contacts in the 3D structure of the tissue. CartoCell enables the quantification of geometric and packing features at the cellular level. Our single-cell cartography approach then maps the distribution of these features on 2D plots and 3D surface maps, revealing cell morphology patterns in epithelial cysts. Additionally, we show that CartoCell can be adapted to other types of epithelial tissues.

Machine Learning-Enabled Quantitative Analysis of Optically Obscure Scratches on Nickel-Plated Additively Manufactured (AM) Samples.

Additively manufactured metal components often have rough and uneven surfaces, necessitating post-processing and surface polishing. Hardness is a critical characteristic that affects overall component properties, including wear. This study employed K-means unsupervised machine learning to explore the relationship between the relative surface hardness and scratch width of electroless nickel plating on additively manufactured composite components. The Taguchi design of experiment (TDOE) L9 orthogonal array facilitated experimentation with various factors and levels. Initially, a digital light microscope was used for 3D surface mapping and scratch width quantification. However, the microscope struggled with the reflections from the shiny Ni-plating and scatter from small scratches. To overcome this, a scanning electron microscope (SEM) generated grayscale images and 3D height maps of the scratched Ni-plating, thus enabling the precise characterization of scratch widths. Optical identification of the scratch regions and quantification were accomplished using Python code with a K-means machine-learning clustering algorithm. The TDOE yielded distinct Ni-plating hardness levels for the nine samples, while an increased scratch force showed a non-linear impact on scratch widths. The enhanced surface quality resulting from Ni coatings will have significant implications in various industrial applications, and it will play a pivotal role in future metal and alloy surface engineering.

Mapping of impervious surfaces with the use of remote sensing imagery: Support Vector Machines classification and GIS-based approach

Mapping of impervious surfaces with the use of remote sensing imagery: Support Vector Machines classification and GIS-based approach

Quad Mesh Quantization Without a T‐Mesh

AbstractGrid preserving maps of triangulated surfaces were introduced for quad meshing because the 2D unit grid in such maps corresponds to a sub‐division of the surface into quad‐shaped charts. These maps can be obtained by solving a mixed integer optimization problem: Real variables define the geometry of the charts and integer variables define the combinatorial structure of the decomposition. To make this optimization problem tractable, a common strategy is to ignore integer constraints at first, then to enforce them in a so‐called quantization step. Actual quantization algorithms exploit the geometric interpretation of integer variables to solve an equivalent problem: They consider that the final quad mesh is a sub‐division of a T‐mesh embedded in the surface, and optimize the number of sub‐divisions for each edge of this T‐mesh. We propose to operate on a decimated version of the original surface instead of the T‐mesh. It is easier to implement and to adapt to constraints such as free boundaries, complex feature curves network etc.

Landsat-derived impervious surface area expansion in the Arctic from 1985 to 2021

Accurate and timely impervious surface mapping is essential for assessing land cover change, urban heat island, and monitoring human activity intensity and ecological change. While various global impervious surface datasets become available, these datasets exhibit significant omissions in Arctic regions. Hence, in this study, we present a 30-m impervious surface area (ISA) dataset of Arctic from 1985 to 2021 (GISA_Arcitc). To this aim, we proposed to combine visually interpreted ISA samples and automatically generated NonISA samples for Arctic ISA mapping. Then, adaptive random forest (RF) classifiers were used for long time-series ISA mapping and the result was post-processed to improve the spatial-temporal consistency. Finally, the accuracy of GISA_Arcitc was assessed using the 37,800 independent test samples. GISA_Arctic possessed an overall accuracy of 93.59 % and a F-score of 0.934. It is found that the Arctic ISA increased from 857.83 km2 to 2115.49 km2 during the past 37 years. More than 84 % of the Arctic ISA increment is embraced by three countries: Russia, Finland, and Norway. Courtesy of the long time-series GISA_Arctic, the sources of Arctic ISA expansion were further analyzed. It was found that the top three land covers transformed to ISA are tundra, forest and grassland. The GISA_Arctic could contribute to further understanding of human activities and Arctic ecological changes, which can be accessed from http://irsip.whu.edu.cn/resources/resources_v2.php.

Planar Reconstruction of Regular Surfaces’ Three-Dimensional Morphology and Tribology Application

The three-dimensional morphology of frictional sub-surfaces holds significant importance for studying tribological issues. However, the uniformity of the horizontal datum in 3D scanning is limited for curved surfaces, resulting in the inability to obtain accurate contour characterization parameters from the scanning results. This study aims to address this issue by constructing regular surface equations and normalizing the 3D profiler scanning results. By fitting the data, a “plane” surface representative of the surface features is obtained, and the paper demonstrates this approach on the surface morphology of different worn parts in the frictional area of spherical bearings located in the specific environment of the Three Gorges gate. The results indicate that the obtained “plane” effectively reconstructs the three-dimensional morphology map of the regular surface. Moreover, this reconstructed plane not only clearly illustrates the surface characteristics but also provides the foundation for analyzing the wear mechanism.

How thick is the Strathbogie Complex?

The Strathbogie Complex is a large granitic body in north central Victoria. Previous detailed mapping of part of its western and southern boundary suggested that the body was relatively thin, probably less than 1 km. However, forward modelling its gravity response suggests the complex is thicker, perhaps more than 6 km in its deepest parts. The only way the measured gravity response could be modelled to fit a maximum thickness of 1.5 km is with an unrealistically low density. While not definitive, the modelling provides a warning that, where available, even excellent surface mapping should be combined with other data to obtain the most realistic subsurface geometries.

Carbonate submarine fan deposits of the Mississippian Lake Valley Formation, Sacramento Mountains, New Mexico

AbstractDeep‐water carbonate deposition is relatively poorly understood but an area of vigorous research in academia and industry, where these deposits are a significant component of many unconventional petroleum reservoirs. Recent studies of modern deep‐water carbonates have highlighted the wide variety of depositional processes, sediment types and resultant geomorphology; however, well‐documented outcrops of ancient systems, their rock types and architecture are relatively sparse. The Mississippian Lake Valley Formation provides world‐class exposures of slope‐basinal carbonate deposits. The Tierra Blanca and Doña Ana members comprise submarine fans that are >14 to 20 km in length, >5 km wide, and exposed in strike and dip view, affording a unique opportunity to constrain the architecture, rock types and sedimentary processes. Tierra Blanca and Doña Ana sedimentation was dominated by crinoids shed from an up‐dip platform and supplemented by sediments sourced locally from Waulsortian mounds. Depositional processes include turbidity flows, debris flows and hybrid sediment‐gravity flows. The Tierra Blanca submarine fan thins towards its lateral flanks and distal fringe, where deposits become more mud‐dominated, gravelly grain‐supported flows are less common, and fewer beds have scoured bases. In proximal settings, bed tracing complemented by measured sections allow mapping of stratal surfaces and identification of stories, elements and complexes. The Tierra Blanca evolved from more unconfined to confined deposition. Point‐sourced deposition of the Tierra Blanca fan required a funnelling mechanism, probably due to bathymetry created by Waulsortian mounds or possibly a platform margin re‐entrant. Outcrop exposures illustrate that younger Doña Ana submarine fan deposits onlap onto, and compensationally stack with, the thickest portions of the antecedent Tierra Blanca fan. These outcrops illustrate both similarities and differences between carbonate and siliciclastic gravity flow deposits. Similarities include comparable deposit types, depositional processes and architecture; differences relate to hydrodynamics of carbonate grains, funnelling mechanisms for point‐sourced deposits and sequence stratigraphic forcing.

Diagnostic value of 3D Optical Coherence Tomography Multimode Images in the Diagnosis of Acute Central Serous Chorioretinopathy.

Spectral-Domain Optical Coherence Tomography (SD-OCT) provides non-invasive, high-speed, high-resolution, three-dimensional cross-section imaging of the macula. This study aimed to investigate the diagnostic value of the multimodal imaging technique of three-dimension (3D) optical coherence tomography (OCT) (3D-OCT) for the diagnosis and characterization of acute central serous chorioretinopathy (CSC). In this prospective clinical study 3D-OCT examinations of 82 cases with acute CSC were performed on the macular area, and the image characteristics were analyzed. Our study included a total of 87 eyes from 82 cases of CSC patients, 67 males and 15 females (mean age ± standard deviation (SD): 42.89 ±7.80 years old; age range: 27 to 56 years old. The 3D-OCT images were evaluated for the presence of subretinal fluid, subretinal space, fluctuation of the internal limiting membrane (ILM), folds of retinal pigment epithelial (RPE), retinal pigment epithelium detachment (PED), and flat irregular PED. The foveal thickness was measured using the manual caliper of OCT software. The OCT B-scan images showed 87 (100%) eyes had exudative retinal detachment (ERD), 38 (44%) had flat irregular PED, 36 (41%) had PED, 8 (9%) had subretinal turbidity structure, 2 (2%) had subretinal dot-like precipitates, 1 (1%) had focal choroidal excavation (FCE), and 1 (1%) eye had fluctuation of internal limiting membrane (FI). In the ILM-RPE thickness map, all eyes had a round or round like regular uniform domes. Fifty-seven (66%) domes were limited in the examination area and 30 (44%) domes were beyond the scope of this examination and only a partial section of the dome could be observed. In the en-face image, all eyes had a round or round-like black figure that corresponded with domes in the ILM-RPE thickness map. In RPE surface, 76 (87%) eyes had a shallow plate depression, 71(82%) had small focal uplift, and 1 (1%) eye had a focal concave feature. In the OCT ILM-RPE thickness, en-face image, and RPE surface maps, acute CSC exhibited specific imaging characteristics that can be helpful for reliable diagnosis and differential diagnosis of CSC.

The Brainstem Cavernoma Case Series: A Formula for Surgery and Surgical Technique.

Background and Objectives: Cavernous malformations (CM) are vascular malformations with low blood flow. The removal of brainstem CMs (BS) is associated with high surgical morbidity, and there is no general consensus on when to treat deep-seated BS CMs. The aim of this study is to compare the surgical outcomes of a series of deep-seated BS CMs with the surgical outcomes of a series of superficially located BS CMs operated on at the Department of Neurosurgery, College of Tuebingen, Germany. Materials and Methods: A retrospective evaluation was performed using patient charts, surgical video recordings, and outpatient examinations. Factors were identified in which surgical intervention was performed in cases of BS CMs. Preoperative radiological examinations included MRI and diffusion tensor imaging (DTI). For deep-seated BS CMs, a voxel-based 3D neuronavigation system and electrophysiological mapping of the brainstem surface were used. Results: A total of 34 consecutive patients with primary superficial (n = 20/58.8%) and deep-seated (n = 14/41.2%) brainstem cavernomas (BS CM) were enrolled in this comparative study. Complete removal was achieved in 31 patients (91.2%). Deep-seated BS CMs: The mean diameter was 14.7 mm (range: 8.3 to 27.7 mm). All but one of these lesions were completely removed. The median follow-up time was 5.8 years. Two patients (5.9%) developed new neurologic deficits after surgery. Superficial BS CMs: The median diameter was 14.9 mm (range: 7.2 to 27.3 mm). All but two of the superficial BS CMs could be completely removed. New permanent neurologic deficits were observed in two patients (5.9%) after surgery. The median follow-up time in this group was 3.6 years. Conclusions: The treatment of BS CMs remains complex. However, the results of this study demonstrate that with less invasive posterior fossa approaches, brainstem mapping, and neuronavigation combined with the use of a blunt "spinal cord" dissection technique, deep-seated BS CMs can be completely removed in selected cases, with good functional outcomes comparable to those of superficial BS CM.

Comparison of dimensional accuracy of 3D printing model for clear aligner among various orientation types and hollow types

ABSTRACT Purpose The objective of this study was to investigate the effect of printing protocol focusing upon the accuracy of 3D-printed dental models. Materials and Methods In total, 6 groups of 10 identical maxillary dental models (Formlabs dental model resin) were produced with a stereolithography (SLA)-based 3D printer using 6 printing protocols, Group 1: Hollow/Horizontal (HH), Group 2: Hollow/Oblique (HO), Group 3: Hollow/Vertical (HV), Group 4: Non-hollow/Horizontal (NHH), Group 5: Non-hollow/Oblique (NHO) and Group 6: Non-hollow/Vertical (NHV). Deviation analysis (GOM Inspect) using the best-fit algorithm was conducted to assess accuracy. Trueness and precision of 5 tooth types which were further classified by 3 surface points on anterior teeth and 5 surface points on posterior teeth, were calculated. Thereafter, Kruskal–Wallis was conducted to determine if there were any differences in trueness/precision among the 6 printing protocols. Results Accuracy of clear aligner models showed significant differences (p < .05) among the 6 printing protocols. Majority of values were within clinically acceptable limits (<0.2 mm) except for first molars and second molars. HV showed significant worst accuracy while NHH was the best printing protocol. Other groups (HH/NHV/HO/NHO) were ranked in middle. Inaccuracy was varied depending on tooth type and surface points. Second molars showed greatest defects at significant level in all printing groups. Color surface maps of 3D model superimposition demonstrated non-uniform deviations. Conclusions The printing protocols with differences in hollow types and printing orientations can significantly affect the dimensional accuracy of 3D printed models for clear aligner. Overall deviations showed location-specific deviations.

First-principles calculation of phase stability and elastic properties of CrxMoNbTiV refractory high-entropy alloys

Compared with traditional alloys, high-entropy alloys (HEAs) have been widely studied because of their unique phase formation rules and excellent physical properties. This work used the first-principle calculation method to study the effect of Cr content on the phase formation, stability, and mechanical properties of MoNbTiV refractory HEAs (RHEAs). The structural model of CrxMoNbTiV (x = 0.00, 0.25, 0.50, …, 2.00) RHEAs was constructed by the virtual crystal approximation method. The structural model was geometrically optimized using the Cambridge Sequential Total Energy Package code, and the structures’ binding energy, enthalpy of formation, and elastic constants were calculated. The results show that the CrxMoNbTiV RHEAs can form a stable body-centered cubic structure, and the addition of Cr significantly impacts the lattice constant, elastic constant, plastic toughness, and elastic anisotropy of the alloy. At the same time, the three-dimensional surface map of Young’s modulus anisotropy is also drawn.

Development of a Hardware Demonstration Platform for Multispacecraft Reconnaissance of Small Bodies

The next frontier in space exploration involves visiting some of the 2 million small bodies scattered throughout the solar system. However, these missions are expected to be challenging due to the surface irregularities of these bodies and the very low gravity, which makes steps like getting into orbit very complex. For these reasons, reconnaissance is crucial for small body exploration before taking on ambitious orbital, surface, and sample-return missions. Our previous work developed IDEAS, an automated design software for small body reconnaissance mission development using spacecraft swarms. A critical challenge to furthering such designs is the lack of hardware demonstration platforms for interplanetary spacecraft operations. In this paper, we present MAPS (Multi-Agent Photogrammetry of Small bodies), a hardware platform to demonstrate critical reconnaissance operations of multi-spacecraft missions identified by the IDEAS framework. MAPS uses UAVs as the autonomous agents that perform reconnaissance operations. The UAVs use their visual feed to generate a 3D surface map of a small body mockup, which is encountered along their flight path. In this paper, we examine the various design elements of a small body surface reconstruction mission inside the MAPS testbed. These elements are used for designing reference trajectories of the participating UAVs, which is enforced using a tracking feedback control law. We then formulate the small-body mapping problem as an MINLP problem, which is handled by the Automated Swarm Designer module of the IDEAS framework. The solutions are implemented inside the MAPS, and shape models generated from the UAV feeds are compared.

Identification of Landslides Controlling and Triggering Factors using the Analytical Hierarchy Process (AHP) in Dermasuci Village, Pangkah District, Tegal Regency, Central Java Province - Indonesia

The National Disaster Management Agency (BNPB) stated that in 2022 around 634 landslides occurred in Indonesia. One of the regions in Indonesia that experienced landslide disasters is Dermasuci Village, Pangkah District, Tegal Regency, Central Java Province. The first landslide disaster occurred on February 5, 2022, and the second landslide occurred on February 10, 2022. The landslide disasters caused damage to 61 residents’ houses and four road sections. The objective of this study is to identify the controlling and triggering factors that mainly contributed to the landslide event. These two factors are determined based on the order of their static and dynamic properties using the analytical hierarchy process (AHP) method. Controlling and triggering factors of the landslide in the study area are determined based on geological and engineering geological conditions which were obtained from surface mapping results. The controlling factors obtained are the rock bedding inclination, geological structure in the form of faults, slope inclination, engineering properties of soil and rock, land use, and groundwater table. The triggering factors that are known and commonly occur are rainfall in the form of antecedents and intensity, and earthquakes that can induce landslides.

Assessment of Spatial Variability Mapping of Soil Properties and its Impacts on Agricultural Productivity using GIS Approach in Siliguri Sub-Division, West Bengal, India

Soil surveying and mapping are extremely important in order to comprehend the characteristics of soil and what applications there are in agriculture, irrigation, urbanisation, and other land uses purposes. A major hindrance to the maximum production of the land is soil degradation brought on by inappropriate land management techniques. Geographical variability mapping of soil parameters is necessary for the agricultural productivity, food safety and environmental modelling. This research was done to identify some of the soil characteristics in the Siliguri Sub-Division. The present study had been conducted in the four blocks of Siliguri Sub-Division, located at the foot hill of the Darjeeling Himalayas in the Terai region of West Bengal, India. To comprehend the geographic variability of soil characteristics using a geospatial technique Soil pH, Phosphorus (P), Organic Carbon (OC), Nitrogen (N), Sulphur (S) and Potassium (K)were measured. To evaluate the current soil status of the area, some important chemical characteristics of the soil were identified. Geographic Information System (GIS) techniques were used to create surface maps of soil attributes, and sampling-broad analysis utilizing GPS was found to be a potentially effective tool. The goal of the study is to use an innovative method to carry out a soil analysis in a newly developed area. The production of digital maps for soil attributes allowed GIS to be used in the study to portray the laboratory results of the soil analysis. Utilizing variable technology, such digital mapping can be utilised in the research on agricultural applications. The result obtained from the research portray that the soil is acidic in nature and the pH value ranges between pH 6.1 to pH 4.5. Moreover, the presence of Nitrogen is between 0.13 to 1.90 %. Organic Carbon ranges between 2.22 to 1.47 %. The range of Potassium is between 32 ppm to 58 ppm, Phosphorus ranges between 09 to 27 ppm and sulphur content ranges between 10.4 to 32.3 ppm. The investigations will assist the development of a sustainable ecological status and proper agricultural system. Subsequently, it will also help to local government, environmentalists, LULC planners to promote any developmental plan related to agriculture and soil in the Siliguri Sub-division.

(Invited) Approaches for Mechanistic Understanding of Electrodeposition Processes for Fabricating Micro/Nano Structures and Devices

Electrochemical deposition processes have precise controllability, selectivity and uniformity, and have been widely applied for fabricating various functional micro/nano structures and devices. In order to achieve further higher controllability for developing reliable process for manufacturing, molecular-level understanding of the deposition processes is required. Furthermore, this can be be also utilized to understand various applications such as the electrode processes of secondary batteries using metal anodes and so on. For this, we have attempted to apply theoretical approaches such as density functional theory (DFT) and kinetic Monte Carlo (KMC) calculations[1.2], as well as experimental methods such as surface enhanced Raman microscopy equipped with plasmonic sensors[3-5]. In this paper, these approaches with some of the resent results will be described. The analysis using DFT calculations provided the molecular-level insights for the catalytic activity of the electroless deposition reaction process at the surface, with the effects of the additive species and solvation. Also, in combination with the KMC calculation, multi-scale simulation for the nucleation and growth process at the Zn anode surface for the secondary battery was attempted. While these approaches enable quantitative discussion for the mechanistic understanding of the processes, we also attempted to obtain "real" data from experimental approaches. For this, we applied surface enhanced Raman scattering (SERS) and developed "plasmonic sensors" with controlled nanostructures to obtain high signal enhancement at electrode-electrolyte interface. We have developed two types of the plasmonic sensors which could achieve extremely high sensitivity. Multi-confocal type SERS microscopy was also developed for mapping and imaging analyses of the electrode surface as well as local pH distributions. By using these techniques, various processes at the electrode surfaces and interfaces have been investigated and modelling of the processes has been carried out.This work was financially supported in part by “Development of Systems and Technology for Advanced Measurement and Analysis” program from Japan Science and Technology Agency, and Grant-in-Aid for Scientific Research, MEXT, Japan.[1] Y. Onabuta, M. Kunimoto, H. Nakai, T. Homma, Electrochim. Acta, 307, 536 (2019).[2] Y. Onabuta, M. Kunimoto, S. Wang, Y. Fukunaka, H. Nakai, T. Homma, J. Electrochem. Soc., 169, 092504 (2022).[3] M. Yanagisawa, M. Saito, M. Kunimoto, T. Homma, Appl. Phys. Express, 9 , 122002 (2016).[4] M. Kunimoto, F. Yamaguchi, M. Yanagisawa, T. Homma, J. Electrochem. Soc., 166, D212 (2019).[5] T. Wang, M. Kunimoto, M. Yanagisawa, M. Morita, T. Abe, T. Homma, Energy Env. Mat., in press (2022).

VIBRATIONAL SPECTROSCOPIC STUDY OF PYRIDINE AND PYRIMIDINE LIGANDS COORDINATED WITH ANTIMONY (III) COMPLEXES: INSIGHTS FROM DFT CALCULATIONS

By employing the Scaled Quantum Mechanics Force Field (SQMFF) methodology, a comprehensive analysis was conducted to assign the vibrational spectra of three antimony (III) compounds, [1a-3a], that possess pyridine and pyrimidine ligands. The potential energy distribution (PED) was calculated and utilized to assign the IR spectra of the antimony (III) compounds. The theoretical frontier molecular orbital descriptors, the partial and total density of state distribution (TDOS, PDOS), molecular electronic potential surface map (MEP), nonlinear optical properties (NLO) of these complexes also were computed and investigated. The DFT/B3LYP/GEN (C, H, N, Cl: 6-31G(d,p) and Sb: LanL2DZ) level was utilized for all DFT calculations using the Gaussian 09W program. Furthermore, theoretical frontier molecular orbital descriptors, including electronegativity, chemical potential, softness, electrophilicity index, and electron affinity for six antimony (III) compounds were calculated ([1a/1b-3a/3b]). The results showed that, the ionization potential energy value of the [3a], which had the lowest experimental Leishmania activity, was also found to be the lowest among the others.