Neighboring Atoms Research Articles

ScFeSb3S7: Synthesis and characterization of a new mixed-metal sulfide

Mixed transition metal chalcogenides are pursued for various semiconducting applications. Herein, we report a new mixed transition metal containing quaternary chalcogenide, ScFeSb3S7, which has been prepared by a high-temperature reaction of elements at 1173 K. A single-crystal X-ray diffraction study shows that the monoclinic ScFeSb3S7 structure (space group: C2/m) is disordered with a mixed Sc and Sb site. The lattice parameters of the structure are a = 12.439(5) Å, b = 3.7938(13) Å, c = 11.604(4) Å, β = 106.095(10)°, and Z = 2. The seven unique crystallographic sites of the structure are occupied, which include Fe1, Sb1, mixed Sc1/Sb2, and four S sites. Each of the Fe1 and Sc1/Sb2 atoms is coordinated with six neighboring sulfur atoms in an octahedral fashion, whereas the Sb1 atom occupies the center of a distorted square pyramidal geometry of the S atoms. The (Sc1/Sb2)S6, FeS6, and SbS5 units are the primary building blocks of the ScFeSb3S7 structure. Both resistivity and optical absorption [Eg = 1.5(1) eV] studies confirm that the ScFeSb3S7 is a semiconductor. A thermal conductivity (ktot) study shows that the polycrystalline sample is a poor thermal conductor with an ultralow ktot value of ∼0.30 W/mK at 773 K. DFT studies also indicate the semiconducting nature of the ScFeSb3S7. The COHP analyses suggest stronger bonding interactions between Sb and S than the Sc/Fe with the S atoms.

Deep insights into the promotion role of Sm doping in the sulfur resistance of Fe2O3 catalyst for NH3-SCR: A combined experimental and DFT study

To investigate the inherent role of Sm doping in metal sulfation over the surface of Fe2O3 catalyst and reveal the reason for the SO2 tolerance enhancement of Sm/Fe2O3 catalyst at low temperatures (<320 °C), sulfated Fe2O3 and Sm/Fe2O3 catalysts were prepared by pretreating fresh catalysts in SO2+O2 atmosphere. Selective catalytic reduction (SCR) of NOx by NH3 activities and physicochemical characteristics of fresh and sulfated catalysts were studied, and the reaction mechanisms on sulfated catalysts analyzed. The minor shift of Fe signal to high value and larger shift of S signal to low value of sulfated Sm/Fe2O3 compared with sulfated Fe2O3 was observed with X-ray photoelectron spectroscopy (XPS), indicating that Sm modification could weaken the sulfation of active Fe sites. Consistent with the XPS results, density functional theory calculations showed that SO2 is more easily adsorbed on the Sm/Fe2O3 catalyst with the adsorption sites located at Sm atom and its neighboring Fe atoms. In-situ DRIFTS results showed that the SCR reaction over the sulfated Fe2O3 catalyst followed both L-H (the adsorbed NH3 species react with adsorbed nitrate species) and E-R (the adsorbed NH3 species react with gaseous NO) mechanisms at 250 °C, with the L-H route much faster, whereas only the L-H pathway occurred over sulfated Sm/Fe2O3 catalyst because of too strong affinity of NH3 on the sulfated sites to inhibit NH3 activation – this was also the reason for its enhanced Lewis and Brønsted acidity. More reactive nitrate species were formed on the sulfated Sm/Fe2O3 catalyst due to the existence of more un-sulfated Fe sites, making the Sm/Fe2O3 catalyst resistant to SO2 poisoning at relatively low temperatures.

New Insights into the Physicochemical and Electrochemical Characterization of Gold Phthalocyanine-Based Materials

Gold phthalocyanine-based materials can allow to combine the unique physical properties of the metallophthalocyanine with gold for numerous applications such as (photo)-electrochemistry or the so-called single atom catalysts (SACs), which require very small amounts of metal. However, there is currently a lack of physico-chemical and electrochemical knowledge to consider such applications. We report the synthesis and the physical characterization of three types of materials, the unsubstituted and the octo-substituted gold phthalocyanines AuPc, AuPc(CN)8 and AuPc(COOH)8, which were successfully synthesized. To interrogate the physicochemical and electrochemical properties of the as-synthesized materials, we have performed a multi-variant study by integrating different methods (UV–vis, FTIRS, TGA-TDA, HR-ESI-MS, SEM-EDX, XRD, XPS, CV). UV–vis confirms the shift towards high wavelengths (bathochromic effect) for the transition Q-band (charge transfer from pyrrolic carbons to neighboring atoms in the macrocycle) of AuPc(CN)8 and AuPc(COOH)8 compared to AuPc. CV in both aqueous and non-aqueous provides the first electrochemical insights into the phthalocyanine ring reduction and oxidation, AuPc/[AuPc]−, [AuPc]−/[AuPc]2− and [AuPc]2−/[AuPc]3−. The results delineate a possible rational pathway for AuPc-based materials or alternatively, their transformation into SACs, where a single Au atom is embedded in a nanostructured carbon-nitrogen scaffold.

Hydrogenation conversion of CO2 molecules on monolayer MoS2 supported (TiO2)n clusters: A first-principles investigation

Adsorption and hydrogenation reaction of CO2 molecules on the surfaces of monolayer MoS2 supported (TiO2)n clusters were investigated using the first principles calculations. Calculation results reveal that small (TiO2)n clusters can be bounded firmly on monolayer MoS2 surface through the formation of chemical bonds between Ti and S atoms. (TiO2)n clusters on the surface of MoS2 can significantly improve the capabilities for CO2 capture. Due to the existence of dangling oxygen atoms of (TiO2)n clusters, CO2 molecules are likely to adsorb on MoS2/(TiO2)n surfaces as bent configurations. H atoms and CO2 molecules co-adsorb stably on the surfaces of MoS2/(TiO2)n, and then realize the hydrogenation conversion of adsorbed CO2 to *COOH through H adatoms migrations. The results suggest that H adatoms can migrate along several specific reaction pathways with relative lower energy barriers. Especially, for MoS2/(TiO2)4 substrate, distal H adatoms could firstly migrate to neighboring oxygen atoms with a lower energy barriers of about 1.12 eV, and further hydrogenation reaction occurs with an activation barrier of about 0.59 eV. These results may provide some useful proposals of catalyst design for hydrogenation conversion of CO2.

Guilty as Charged: The Role of Undercoordinated Indium in Electron-Charged Indium Phosphide Quantum Dots.

Quantum dots (QDs) are known for their size-dependent optical properties, narrow emission bands, and high photoluminescence quantum yield (PLQY), which make them interesting candidates for optoelectronic applications. In particular, InP QDs are receiving a lot of attention since they are less toxic than other QD materials and are hence suitable for consumer applications. Most of these applications, such as LEDs, photovoltaics, and lasing, involve charging QDs with electrons and/or holes. However, charging of QDs is not easy nor innocent, and the effect of charging on the composition and properties of InP QDs is not yet well understood. This work provides theoretical insight into electron charging of the InP core and InP/ZnSe QDs. Density functional theory calculations are used to show that charging of InP-based QDs with electrons leads to the formation of trap states if the QD contains In atoms that are undercoordinated and thus have less than four bonds to neighboring atoms. InP core-only QDs have such atoms at the surface, which are responsible for the formation of trap states upon charging with electrons. We show that InP/ZnSe core-shell models with all In atoms fully coordinated can be charged with electrons without the formation of trap states. These results show that undercoordinated In atoms should be avoided at all times for QDs to be stably charged with electrons.

Recent Advances in the Synthesis of Pyrazole Derivatives: A Review

Pyrazole, characterized by a five-membered heterocyclic structure featuring two neighboring nitrogen atoms, serves as a core element. Pyrazoles hold a privileged status as versatile frameworks in various sectors of the chemical industry, including medicine and agriculture. Previous reviews have extensively highlighted the significance of pyrazoles and their diverse biological activities, encompassing roles such as antituberculosis, antimicrobial, antifungal, anti-inflammatory, anticancer, and antidiabetic agents. Consequently, they have garnered substantial interest from researchers. The aim of this review is to offer a comprehensive overview of the published research related to the synthesis of pyrazole derivatives, encompassing a discussion of diverse methods for accessing the pyrazole moiety. These methods span from utilizing transition-metal catalysts and photoredox reactions to employing one-pot multicomponent processes, novel reactants, and innovative reaction types. It encompasses studies conducted by numerous scientists worldwide, showcasing collective efforts in advancing the methodologies and applications of pyrazole derivatives.

Competitive Formation Mechanism for Bidentate Passivation of Halogen Vacancies in Perovskite Based on 6-Chloropurine.

For metal halide perovskite solar cells, bidentate passivation (BP) is highly effective, but currently, only passivation sites rather than molecular environments are being considered. Here, the authors report an effective approach for high-performance fully printable mesoscopic perovskite solar cells (FP-PSCs) through the BP strategy using the multidentate molecule 6-chloropurine (6-CP). By utilizing density functional theory (DFT) calculations, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) characterizations, the competition mechanism is identified of BP between the chlorine atom and neighboring nitrogen atom of the imidazole and pyrimidine rings. Through BP between the chlorine atom and adjacent nitrogen atom in imidazole, the power conversion efficiency (PCE) of the pristine samples is significantly enhanced from 16.25% to 17.63% with 6-CP. The formation of BP enhances interfacial hole selectivity and charge transfer, and suppresses nonradiative recombination, improving device stability under high humidity conditions. The competition mechanism of BP between two aromatic cycles provides a path for designing molecular passivants and selecting passivation pathways to approach theoretical limits.

MLIP-3: Active learning on atomic environments with moment tensor potentials.

Nowadays, academic research relies not only on sharing with the academic community the scientific results obtained by research groups while studying certain phenomena but also on sharing computer codes developed within the community. In the field of atomistic modeling, these were software packages for classical atomistic modeling, and later for quantum-mechanical modeling; currently, with the fast growth of the field of machine-learning potentials, the packages implement such potentials. In this paper, we present the MLIP-3 package for constructing moment tensor potentials and performing their active training. This package builds on the MLIP-2 package [Novikov et al., "The MLIP package: moment tensor potentials with MPI and active learning," Mach. Learn.: Sci. Technol., 2(2), 025002 (2020)], however, with a number of improvements, including active learning on atomic neighborhoods of a possibly large atomistic simulation.

Insights into the effect of γ′- or γ′′-precipitated phase types on resistance against harmful atoms of heterogeneous interface in nickel-based superalloys

To improve the service performances of nickel-based superalloys by controlling the type and proportion of precipitate phases, the resistances against harmful atoms (weakening effect caused by harmful atoms and capacity for hindering intrusion of harmful atoms) of the representative γ-matrix/γ′- or γ′′-precipitated phase heterogeneous interfaces (γ-Ni/γ′-Ni3Al, γ-Ni/γ′-Ni3Ti, and γ-Ni/γ′′-Ni3Nb interfaces) was investigated. The results show that, the harmful atoms (H, O, and S atoms) can be stable adsorbed on heterogeneous interfaces and weaken the interfacial bonding strength, resulting in the fracture position change from γ′- or γ′′ slab to interface during tensile deformation. Because of the minimum changes on interfacial bonding characteristics after the intrusion of harmful atoms, γ-Ni/γ′′-Ni3Nb heterogeneous interface (HIγ″−Ni3Nb) demonstrates the strongest resistance against weakening effect, presented as the smallest deterioration of interfacial ideal work of adhesion and tensile strength. Meanwhile, the energy barrier of harmful atoms diffusing along HIγ″−Ni3Nb is much larger than those along HIγ″−Ni3Al and HIγ″−Ni3Ti, leading to a smallest diffusion coefficient for harmful atoms diffusing along HIγ″−Ni3Nb. The result indicates HIγ″−Ni3Nb also shows the strongest capacity for hindering the intrusion of harmful atoms. This phenomenon is attributed to the strongest interaction between harmful atoms on saddle point and the neighboring atoms on HIγ″−Ni3Nb during the diffusion process. To summary, the Ni-based superalloys with γ′′-Ni3Nb as the main precipitated phase demonstrate the most promising properties in resistance against harmful atoms. This work not only contributes to the further improvement of Ni-based superalloys, but also provides the creative ideas for the research of other superalloys.

Prediction of pathogenic single amino acid substitutions using molecular fragment descriptors.

Next Generation Sequencing technologies make it possible to detect rare genetic variants in individual patients. Currently, more than a dozen software and web services have been created to predict the pathogenicity of variants related with changing of amino acid residues. Despite considerable efforts in this area, at the moment there is no ideal method to classify pathogenic and harmless variants, and the assessment of the pathogenicity is often contradictory. In this article, we propose to use peptides structural formulas of proteins as an amino acid residues substitutions description, rather than a single-letter code. This allowed us to investigate the effectiveness of chemoinformatics approach to assess the pathogenicity of variants associated with amino acid substitutions. The structure-activity relationships analysis relying on protein-specific data and atom centric substructural multilevel neighborhoods of atoms (MNA) descriptors of molecular fragments appeared to be suitable for predicting the pathogenic effect of single amino acid variants. MNA-based Naïve Bayes classifier algorithm, ClinVar and humsavar data were used for the creation of structure-activity relationships models for 10 proteins. The performance of the models was compared with 11 different predicting tools: eight individual (SIFT 4G, Polyphen2 HDIV, MutationAssessor, PROVEAN, FATHMM, MVP, LIST-S2, MutPred) and three consensus (M-CAP, MetaSVM, MetaLR). The accuracy of MNA-based method varies for the proteins (AUC: 0.631-0.993; MCC: 0.191-0.891). It was similar for both the results of comparisons with the other individual predictors and third-party protein-specific predictors. For several proteins (BRCA1, BRCA2, COL1A2, and RYR1), the performance of the MNA-based method was outstanding, capable of capturing the pathogenic effect of structural changes in amino acid substitutions. Supplementary data are available at Bioinformatics online.

Origin of medium-range atomic correlation in simple liquids: Density wave theory

The atomic pair-distribution function of simple liquid and glass shows exponentially decaying oscillations beyond the first peak, representing the medium-range order (MRO). The structural coherence length that characterizes the exponential decay increases with decreasing temperature and freezes at the glass transition. Conventionally, the structure of liquid and glass is elucidated by focusing on a center atom and its neighboring atom shell characterized by the short-range order (SRO) and describing the global structure in terms of overlapping local clusters of atoms as building units. However, this local bottom-up approach fails to explain the strong drive to form the MRO, which is different in nature from the SRO. We propose to add an alternative top-down approach based upon the density wave theory. In this approach, one starts with a high-density gas state and seeks to minimize the global potential energy in reciprocal space through density waves using the pseudopotential. The local bottom-up and global top-down driving forces are not mutually compatible, and the competition and compromise between them result in a final structure with the MRO. This even-handed approach provides a more intuitive explanation of the structure of simple liquid and glass.

Mapping Nanoscale Electrostatic Field Fluctuations around Graphene Dislocation Cores Using Four-Dimensional Scanning Transmission Electron Microscopy (4D-STEM).

Defects in crystalline lattices cause modulation of the atomic density, and this leads to variations in the associated electrostatics at the nanoscale. Mapping these spatially varying charge fluctuations using transmission electron microscopy has typically been challenging due to complicated contrast transfer inherent to conventional phase contrast imaging. To overcome this, we used four-dimensional scanning transmission electron microscopy (4D-STEM) to measure electrostatic fields near point dislocations in a monolayer. The asymmetry of the atomic density in a (1,0) edge dislocation core in graphene yields a local enhancement of the electric field in part of the dislocation core. Through experiment and simulation, the increased electric field magnitude is shown to arise from "long-range" interactions from beyond the nearest atomic neighbor. These results provide insights into the use of 4D-STEM to quantify electrostatics in thin materials and map out the lateral potential variations that are important for molecular and atomic bonding through Coulombic interactions.

The Role of Conjugation in the Halogen-Lithium Exchange Selectivity: Lithiation of 4,6,7,9-Tetrabromo-1,3-dimethyl-2,3-dihydro-1H-perimidine.

The first case of successful suppression of the coordination of a lithium atom with a dialkylamino group by the effective conjugation of the latter with the aromatic core has been discovered. This effect controls regioselectivity of the bromine-lithium exchange in 4,6,7,9-tetrabromo-1,3-dimethyl-2,3-dihydro-1H-perimidine, which leads to products with the most effective conjugation. As a result, the product of this quadruple exchange demonstrates no tendency of the coordination of the NMe groups to neighboring lithium atoms despite the absence of steric restrictions. Experimental results are explained by means of quantum chemical calculations: geometry optimization, natural bond analysis and scans using the modredundant scheme.

Periodic anti-phase boundaries and crystal superstructures in PtCu3 nanoparticles as fuel cell electrocatalysts

To reduce the cost of the electrocatalyst for the oxygen reduction reaction in proton exchange membrane fuel cells, supported metal alloy nanoparticles are commonly used to decrease the amount of the scarce and expensive Pt. Since the structure of the nanoparticles has a crucial influence on the catalytic properties, advanced characterization methods help elucidate these relationships and ultimately enable more rational synthesis. This work focuses on investigating the presence of one particular planar defect, namely periodic anti-phase boundaries in carbon-supported PtCu3 nanoparticles. The studying of this structural phenomenon was approached with several characterization tools. Ex-situ X-ray diffractograms were used in conjunction with computer simulations and Rietveld analyses to reliably determine the modulated unit cell containing anti-phase boundaries, while their temperature-dependent formation and disappearance were observed with high-temperature X-ray powder diffraction. In addition, their presence was also confirmed by electron diffraction and atomically resolved scanning transmission electron microscopy. Furthermore, the average neighborhood of Cu and Pt atoms was confirmed using extended X-ray absorption fine structure. Finally, the electrocatalytic activity for the oxygen reduction reaction for composites with and without anti-phase boundaries was determined using a thin-film rotating disk electrode, and the performance was found to correlate with the degree of alloy ordering but not with the presence of anti-phase boundaries. Overall, this study represents a significant step towards better control over the atomically precise synthesis of advanced functional metallic materials by providing valuable insight into the formation of planar defects in metallic alloy nanoparticles and their impact on the structure-property relationships of electrocatalysts.

London Dispersion Effects on the Stability of Heavy Tetrel Molecules.

London dispersion (LD) interactions, which stem from long-range electron correlations arising from instantaneously induced dipoles can occur between neighboring atoms or molecules, for example, between H atoms within ligand C-H groups. These interactions are currently of interest as a new method of stabilizing long bonds and species with unusual oxidation states. They can also limit reactivity by installing LD enhanced groups into organic frameworks or ligand substituents. Here, we address the most recent advances in the design of LD enhanced ligands, the sterically counterintuitive structures that can be generated and the consequences that these interactions can have on the structures and reactivity of sterically crowded heavy group 14 species.

Spectroscopic and Theoretical Studies on Conformational Stability of Benzyl Methyl Ether.

Conformer-selected electronic and vibrational spectra of benzyl methyl ether and its terminal methyl group-substituted derivative in a supersonic jet have been measured using ultraviolet (UV)-UV hole burning and fluorescence-detected infrared spectroscopy to investigate the conformational stability of flexible molecules. Various quantum chemical calculations as well as experimental observations reveal the coexistence of three conformers with different CCOC dihedral angles and side-chain orientations relative to the benzene ring plane. Vibrational analysis in the excited state with time-dependent density functional theory and IR simulations containing anharmonic coupling sufficiently reproduce the experimental results, suggesting that these three conformers can be distinguished into one gauche-conformer and two trans-ones with respect to the CCOC dihedral angle. We also observe that the gauche conformer exhibits higher-frequency CH2 modes. The natural bond orbital analysis indicates that this phenomenon is attributed to the electron delocalization from the non-bonding orbitals and the C-O orbitals associated with the neighboring oxygen atom, which leads to a conformer dependence of the methylene C-H bond strength.

MOF衍生的单原子催化剂中γN原子在ORR反应中的远程作用及其调制机制

The development of fuel cells is conducive to achieving carbon peaking and carbon neutrality goals, but the oxygen reduction reaction (ORR) of its cathodes is still kinetically slow due to multi-step proton-coupled electron transfer. Currently, metal-organic frameworks-derived single-atom catalysts (SACs) are emerging as efficient ORR catalysts. However, the outer layer structure of the active site is difficult to be determined, resulting in the uncertainty of the reaction mechanism. Here, the dual effect of the outer γN atom on its neighboring βC atom and the distant metal center was investigated. The results show that the doping of γN with different locations and amounts changes the electronic configuration of the replaced C sites in Fe-N4/C-γNx structures, which in turn affects the charge distribution of the βC atom closer to the metal center. And these changes indirectly affect the electron distribution and spin of the metal center through long-range effects, significantly enhancing the ORR performance of the 4-e− paths. More importantly, the electronegativity-enhanced βC atoms are thus more likely to adsorb the OH moiety in alkaline electrolyte typically used in experiments. Thus, a γN-modulated βC-assisted pathway was predicted and a higher thermodynamic limiting potential of ORR than that of the common 4-e− pathway was achieved. Further wavefunction analysis, based on the potential limiting steps, provided an understanding on the electronic level and revealed the significance of precise design and characteristics of γN site in analogous SACs.

Synthesis, Structural and Magnetic Characterization of Superparamagnetic Ni0.3Zn0.7Cr2−xFexO4 Oxides Obtained by Sol-Gel Method

The sol-gel process was used to produce ferrite Ni0.3Zn0.7Cr2−xFexO4 compounds with x = 0, 0.4, and 1.6, which were then subsequently calcined at several temperatures up to 1448 K for 48 h in an air atmosphere. X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and 57Fe Mössbauer spectrometry were used to examine the structure and magnetic characteristics of the produced nanoparticles. A single-phase pure Ni0.3Zn0.7Cr2−xFexO4 nanoparticle had formed. The cubic Fd3¯m spinel structure contained indexes for all diffraction peaks. The crystallite size is a perfect fit for a value of 165 ± 8 nm. Based on the Rietveld analysis and the VSM measurements, the low magnetization Ms of Ni0.3Zn0.7Cr2−xFexO4 samples was explained by the absence of ferromagnetic Ni2+ ions and the occupancy of Zn2+ ions with no magnetic moments in all tetrahedral locations. Moreover, because of the weak interactions between Fe3+ ions in the octahedral locations, the magnetization of the current nanocrystals is low or nonexistent. According to Mössbauer analyses, the complicated hyperfine structures are consistent with a number of different chemical atomic neighbors, such as Ni2+, Zn2+, Cr3+, and Fe3+ species that have various magnetic moments. A Fe-rich neighbor is known to have the highest values of the hyperfine field at Fe sites, while Ni- and Cr-rich neighbors are responsible for the intermediate values and Zn-rich neighbors are responsible for the quadrupolar component.

Application of DFT and TD-DFT on Langmuir Adsorption of Nitrogen and Sulfur Heterocycle Dopants on an Aluminum Surface Decorated with Magnesium and Silicon

In this study, we investigated the abilities of nitrogen and sulfur heterocyclic carbenes of benzotriazole, 2-mercaptobenzothiazole, 8-hydroxyquinoline, and 3-amino-1,2,4-triazole-5-thiol regarding adsorption on an Al-Mg-Si alloy toward corrosion inhibition of the surface. Al-Si(14), Al-Si(19), and Al-Si(21) in the Al-Mg-Si alloy surface with the highest fluctuation in the shielding tensors of the “NMR” spectrum generated by intra-atomic interaction directed us to the most influence in the neighbor atoms generated by interatomic reactions of N → Al, O → Al, and S → Al through the coating and adsorbing process of Langmuir adsorption. The values of various thermodynamic properties and dipole moments of benzotriazole, 2-mercaptobenzothiazole, 8-hydroxyquinoline, and 3-amino-1,2,4-triazole-5-thiol adsorbed on the Al-Mg-Si increased by enhancing the molecular weight of these compounds as well as the charge distribution between organic compounds (electron donor) and the alloy surface (electron acceptor). Finally, this research can build up our knowledge of the electronic structure, relative stability, and surface bonding of various metal alloy surfaces, metal-doped alloy nanosheets, and other dependent mechanisms such as heterogeneous catalysis, friction lubrication, and biological systems.

Local atomic configurations in mechanically alloyed amorphous (FeCoNi)70Ti10B20 powders

The atomic structure of amorphous (FeCoNi)70Ti10B20 alloy synthesized by mechanical alloying was investigated using high energy synchrotron X-ray diffraction and inverse Monte Carlo simulations of pair distribution functions. Empirical potential structure refinement indicates a chemical short-range order at the length scales of 2.1–2.5 Å via local atomic arrangements forming deformed bcc-like clusters. The structural model obtained was described by bond lengths, coordination numbers, and bond angle distribution functions determined for the first neighbor atoms by x-ray scattering supplemented with 3D Monte Carlo simulations.