2p Electrons Research Articles

Structural characterisation, Hirshfeld surfaces, DSC, periodic DFT modeling, vibrational and optical study of heptylenediammonium pentachlorobismuthate H3N(CH2)7NH3BiCl5

A perspective hybrid material, NH3(CH2)7NH3BiCl5, was extensively characterized by structural, DSC, spectroscopic (FT-IR, FT-Raman, and UV-fluorescence) and theoretical (periodic DFT/GGA/PBE) methods. The structural features, noncovalent interactions between molecules in the crystal and electronic structure were examined and discussed in relation to the phase transitions, vibrational characteristics and optical properties. The compound crystallizes at 296 ​K in orthorhombic system (Pbcn space group, Z ​= ​8). The Cl⋯H/H⋯Cl intermolecular contacts act as the major contributor (77.2%) in the crystal. The compound was stable from the ambient temperature to 503 ​K, and it underwent one-reversible phase transition of second order type near 498 ​K, at heating. Characteristic bands in FT-IR (400-4000 ​cm-1) and FT-Raman (50-3500 ​cm-1) spectra were interpreted based on factor group analysis and calculated vibrational spectrum. The UV-fluorescence excitation at 396 ​nm and the visible region emission at 483 ​nm, which are of Cl(3p) ↔ Bi(6p) electron transition character, suggest potential applications as UV-filters and blue photoluminescent emmiters.

Field-induced electron transfer in magnetostrictive material Fe81Ga19

The effect of magnetic fields on the local structure of the Fe81Ga19 alloy was investigated by X-ray absorption fine spectroscopy (XAFS) technique. The results demonstrate that 0.6 T magnetic fields lead to the increasing of the 3d, 4s and 4p electrons of Fe atoms, but the decreasing of the 4p electrons of Ga atoms. The electron transfer from Ga to Fe with applying magnetic fields is revealed. The magnetic fields increase the Fe–Ga bond length. The role of the Fe–Ga bond in determining the magnetostriction is revealed.

Adsorption performance and mechanism of the commonly used collectors with Oxygen-containing functional group on the ilmenite surface: A DFT study

Flotation is the main method to purify ilmenite, the success of flotation is closely related to the effective adsorption of collectors on the mineral surface. Herein, the coordination chemistry adsorption mechanism of the commonly used collectors with oxygen-containing functional groups on ilmenite surface were systematically investigated by first-principles DFT calculations. Adsorption energy results shows that the O bearing pnictogen compounds are the best for ilmenite beneficiation among all the oxygen-containing collectors. In the O-bearing pnictogen compounds, the collection performance of arsenic acid is the best, followed by phosphorous acid and phosphoric acid ester. The frontier molecular orbital analysis predicted that the collectors possessed a good chemical bonding ability with ilmenite, which is confirmed by the charge population analysis that there is significant electron transfer (bonding evidence) between collectors and ilmenite. Partialdensityofstates analysis further confirmed that the physicochemical nature of the adsorption of the collectors on the surface Ti site were ascribed to the hybridization of O 2p and Ti 3d, in which the O 2p electrons of the collectors occupied the empty orbital of Ti 3d to complete the coordination shell of surface Ti atom. This work sheds new light on the screening of solidophilic functional groups for the collector design of ilmenite beneficiation and helps to explain the adsorption mechanism of oxygen-containing collectors on the oxidized mineral surface.

Constructing ample active sites in nitrogen-doped carbon materials for efficient electrocatalytic carbon dioxide reduction

Seeking catalysts with high density of active sites of N-doped carbon nanomaterials is desired for effective conversion of CO2 to CO. Here, the density functional theory (DFT) calculation is employed to investigate the formation energy and chemical potential of N species from different N-containing carbon precursors. It is found that the hybrid precursors facilitate to form high density of the pyridinic-N active sites, owing to its lower formation energy of pyridinic-N. Accordingly, we develop a hybridization strategy of precursors to fabricate the N-doped porous carbon (NPC) with a pyridinic-N content of 2.86 wt% by ball milling of the poly(aniline-co-pyrrole) copolymer in the presence salt templets, followed by pyrolysis. As expected, the optimized NPC1:0.5 exhibits an excellent activity toward CO2RR with the CO Faradaic efficiency of ∼95.3% and a high CO current density of 4.3 mA cm−2, higher than most of the previous reports. Besides, this NPC had CO current density of 115.9 mA cm−2 and a long-term stability for 20 h in flow cell. The experiments and DFT calculation show that the pyridinic-N species act as active sites for CO2RR. In addition, 2p electrons of pyridinic-N species promote *COOH intermediate release to enhance CO2 conversion toward CO.

Amorphous to crystalline transformation of indium sulphide powders on thermal treatment: Studies by x-ray photoelectron spectroscopy and Raman spectroscopy

Amorphous, partially crystalline and polycrystalline indium sulphide (In2S3) obtained on the heat treatment of wet-chemically synthesized In2S3 powders, at 373, 523 and 673 K temperatures respectively in argon atmosphere have been examined by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The binding energies of In(3d) and S(2p) electrons decrease on the transformation of the compound from its amorphous to polycrystalline (β-In2S3) state. The co-existence of amorphous and crystalline phases in the partially crystalline material is conclusively demonstrated by the occurrence of as many peaks in the In(3d) electron spectrum. The XPS measurements also indicate the prevalence of β-In2S3 in subtle amounts in the amorphous In2S3 powder and a certain content of amorphous In2S3 in the material heat treated at 673 K. The higher binding energies of In 3d5/2 electrons (446 eV) and S 2p3/2 electrons (163.3 eV) in amorphous In2S3 can be attributed to the lack of extra-atomic relaxation. The relative shifts of the binding energies suggest that the bonding is more ionic in the crystalline phase. The polycrystalline material has Raman spectrum typical of β-In2S3 indicating a crystal ordering initially with the formation of InS4 tetrahedra and subsequently with, InS6 octahedra as the temperature of the treatment is increased to 673 K. The Raman spectrum, too, points to the prevalence of a certain amorphicity in the compound.

Semimetallic nature of and magnetic polarons in EuB$$_6$$ studied using angle-resolved photoemission spectroscopy

Temperature-dependent angle-resolved photoemission spectroscopy (ARPES) was carried out on single-crystalline EuB6 samples. By measuring ARPES spectra in an extended Brillouin zone, a B 2p hole pocket centered at the X point is clearly observed, thus proving the semimetallic nature of EuB6. Below the Curie temperature TC, ARPES spectra show two B 2p bands of which separation is due to an exchange interaction between local Eu 4f and itinerant B 2p electrons. The exchange splitting becomes smaller as the temperature increases and disappears well above TC. Additionally, a diffuse structure near the Fermi level survives just above TC. Such behavior is well described by Monte Carlo simulations of a Kondo lattice model, thus supporting the formation of magnetic polarons in EuB6, which accounts for the resistivity upturn near above TC when lowering the temperature.

Electronic and optical properties of ZnSe by theoretical simulation TB-mBJ (Tran-Blaha modified Becke Johnson) associated to analysis techniques XPS (X-Ray Photoelectron Spectroscopy); REELS (Reflective Electron Energy Loss Spectroscopy) and PLS (Photoluminescence Spectroscopy)

Our work aims to establish a correspondence between the obtained theoretical and experimental results on the electronic and optical properties of ZnSe.The calculated DOS (Density of States) using the FP-LAPW method with the Tran-Blaha modified Becke-Johnson exchange-correlation potential reveal that the upper valence energy levels involve an important contribution from the Se-(4p and 3d) electron states with a small contribution from the Zn-2s states.The real (ε1(ω)) and imaginary (ε2(ω)) parts of the dielectric function show the anisotropy character of w-ZnSe.The main peaks appearing in the ε2(ω) spectrum, are calculated by summing over all contributions of electronic transitions between the pairs of bands Vn→Cn′, where Vn is an occupied valence band and Cn′ is an unoccupied conduction band. Experimentally, the XPS (X-Ray Photoelectron Spectroscopy) analysis technique is used to show the clean and homogeneous state of ZnSe. To confirm the calculated electron transitions, we use the REELS (Reflected Electron Energy Loss Spectroscopy) technique of great sensitivity for displaying the electron interband transitions. The electron states in the w-ZnSe gap are determined through the Gaussian deconvolution of the photoluminescence spectrum (PLS).

Identification of Auger mechanisms responsible for low energy electron emission from graphene on copper using Auger-gamma coincidence spectroscopy

We have applied positron annihilation induced Auger-gamma coincidence spectroscopy to identify important mechanisms responsible for the emission of low energy electrons following the sudden creation of holes in bilayer graphene on copper substrate. The novel surface spectroscopic method measures the energy of the Doppler shifted annihilation gamma photon in coincidence with the Auger electron emitted following the relaxation of the hole created by the annihilation of a surface electron with a surface trapped positron. By extracting and theoretically modelling the annihilation gamma spectra coincident with low energy electrons, we associate majority of the intensity in the low energy (7 eV–25 eV) region of the Auger spectrum to electron emission following Auger decays of 2s holes in adsorbed oxygen and deep valence holes in graphene. We provide additional support to this conclusion by showing that most of the Auger electrons with energy less than ∼ 25 eV are coincident with gamma photons with small Doppler shift (511 keV–512 keV) indicating that the primary electron whose annihilation resulted in low energy Auger electron emission had small momentum parallel to the gamma emission direction. On the other hand, majority of the Auger electrons measured in coincidence with the photons having maximum Doppler shift (515 keV–521 keV) were emitted following the decay of core holes (C 1s and O 1s). By selecting annihilation gamma photons coincident only with the O KVV (from surface adsorbed oxygen), C KVV (graphene), and Cu MVV (copper substrate) Auger electrons, we have also experimentally derived the energy spectrum of Doppler shifted gamma photons resulting from the annihilation of positrons with 1s electrons of O, 1s electrons of C and 3p electrons of Cu respectively. Model Doppler broadened gamma spectra produced using ab-initio calculations agree well with the experimentally derived line shapes. This demonstrates the ability of Auger-gamma coincidence method to experimentally resolve the Doppler broadened annihilation gamma spectrum from surfaces into its veiled electronic level constituents which has, heretofore, relied solely on theoretical analysis. Our results also demonstrate that the line shape of the Doppler broadened annihilation gamma peak reflect the chemical composition of the topmost atomic layer and can thus be used to characterize both external and inaccessible surfaces of porous materials.

Nitrogen doping and oxygen vacancy effects on the fundamental properties of BeO monolayer: a DFT study

In practice, modifying the fundamental properties of low-dimensional materials should be realized before incorporating them into nanoscale devices. In this paper, we systematically investigate the nitrogen (N) doping and oxygen vacancy (OV) effects on the electronic and magnetic properties of the beryllium oxide (BeO) monolayer using first-principles calculations. Pristine BeO single layer is a non-magnetic insulator with an indirect K–Γ gap of 5.300 eV. N doping induces a magnetic semiconductor nature, where the spin-up and spin-down band gaps depend on the dopant concentration and N–N separation. Creating one OV leads to the energy gap reduction of 31.06% with no spin-polarization, which is due to the abundant 2p electrons of the Be atoms nearest the OV site. The further increase to two OVs and varying the OV–OV distance affect the band gap values, however the spin independence is retained. The magnetic semiconducting behavior is also obtained by the simultaneous N doping and OV presence. Calculations reveal significant magnetization of the BeO@1N, BeO@2N-n, BeO@NOV-n systems, which is produced mainly by the spin-up N–2p state. Except for the BeO@NOV-1 and BeO@NOV-2, whose magnetic properties are created by the spin-up 2p state of the Be atoms closest to the OV site. The variation of the N–N and N–OV distances keeps the ferromagnetic ordering in the BeO@2N and BeO@NOV layers. Results presented herein may propose efficient methods to artificially modify the physical properties of BeO monolayer, leading to the formation of novel two-dimensional (2D) materials for optoelectronic and spintronic applications.

Identifying active sites of boron, nitrogen co-doped carbon materials for the oxygen reduction reaction to hydrogen peroxide

The electrochemical synthesis of hydrogen peroxide (H2O2) from two-electron oxygen reduction reaction (2e- ORR) is a promising alternative for producing chemicals on demand, but its widespread application is still hampered by the low efficiency. Here, we successfully prepared a boron and nitrogen co-doped porous carbon (B/NC) aerogel with a tunable B, N co-doped configuration by the gelation of PVA-graphene, borax and PANI, followed by pyrolysis. Due to a hierarchical porous structure and optimized B, N co-doping, B/NC aerogel showed an excellent electrocatalytic performance for H2O2 production in alkaline solution with a high H2O2 selectivity (94.16%) at positive applied potential (0.6 V vs. RHE), superior than most of the other reported electrocatalysts. Density functional theory (DFT) calculations reveal that the hexagonal boron nitride (hBN) coupled with neighboring pyridinic-N species act as the active sites to lower free energy barrier for formation of HOO* intermediate, thus facilitating H2O2 production. Practically, B 2p electron plays an important role for the adsorption of HOO* intermediates. B and Nco-doping into carbon materials provides an effective and facile method to reasonably construct carbon-based catalysts for electroreduction of O2 to H2O2.

Ultrafast x-ray pump x-ray probe transient absorption spectroscopy: A computational study and proposed experiment probing core-valence electronic correlations in solvated complexes.

Femtosecond x-ray pump-x-ray probe experiments are currently possible at free electron lasers such as the linac coherent light source, which opens new opportunities for studying solvated transition metal complexes. In order to make the most effective use of these kinds of experiments, it is necessary to determine which chemical properties an x-ray probe pulse will measure. We have combined electron cascade calculations and excited-state time-dependent density functional theory calculations to predict the initial state prepared by an x-ray pump and the subsequent x-ray probe spectra at the Fe K-edge in the solvated model transition metal complex, K4FeII(CN)6. We find several key spectral features that report on the ligand-field splitting and the 3p and 3d electron interactions. We then show how these features could be measured in an experiment.

A Noncentrosymmetric Polymorph of LuRuGe.

We report a new polymorph of LuRuGe, obtained in indium flux. This phase exhibits the noncentrosymmetric ZrNiAl-type structure with the space group P6̅2m as determined by single-crystal X-ray diffraction. This polymorph can convert into another centrosymmetric polymorph (TiNiSi-type structure, space group Pnma) at high temperatures. We performed electrical transport, magnetization, and specific heat measurements on this new phase. It shows metallic behavior with a Hall sign change from negative at 2 K to positive at 125 K. LuRuGe exhibits Pauli paramagnetism as the ground state with no local magnetic moments from either the Ru or Lu site. The Debye temperature Θ = 348 K and electronic coefficient γe = 3.6 mJ K-2 mol-1 are extracted from the low-temperature specific heat data in LuRuGe. We also carried out first-principles density functional theory calculations to map out the electronic band structure and density of states. There are several electronic bands crossing the Fermi level, supporting a multiband scenario consistent with the Hall sign change. The density of states around the Fermi level is mainly from Ru 4d and Ge 4p electrons, indicating a strong hybridization between those atomic orbitals.

Effect of plasma screening on electron impact excitation and ionization of Fe16+ in a dense environment

ABSTRACT Electron impact excitation and ionization with atoms and ions within a dense plasma are fundamental microscopic processes that determine the ionization balance, physical properties (such as electron conductive opacity and thermal conductivity) and plasma formation and dynamics. While collision cross-sections and rates are well studied in dilute systems, similar investigations are scarce for dense plasmas under stellar interior conditions using an appropriate plasma-screening potential. Here we investigate the plasma-screening effect on the electron impact excitation and ionization cross-sections, effective collision strengths, and rate coefficients within plasmas under stellar interior conditions in a mass density range of 1–15.748 g cm−3 and a temperature range of 200–1000 eV. These investigations were carried out using our recently developed plasma-screening model, taking Fe16+ as an example. The results show that the cross-sections of the electron impact excitation are generally decreased, whereas they are always significantly increased for the collision ionization due to the plasma screening. In a plasma at a temperature of 200 eV and density of 15.748 g cm−3, the plasma screening causes a decrease in the excitation cross-section of 36 per cent for the dipole-allowed transition $2\mathrm{ s}^22\mathrm{ p}^6~^1\mathrm{ S}_0 \rightarrow 2\mathrm{ s}^22\mathrm{ p}^53\mathrm{ d}~^1\mathrm{ P}^o_1$ and of 50 per cent for the dipole-forbidden transition $2\mathrm{ s}^22\mathrm{ p}^6~^1\mathrm{ S}_0 \rightarrow 2\mathrm{ s}^22\mathrm{ p}^53\mathrm{ d}~^3\mathrm{ D}^o_1$. However, the collision ionization cross-section of a 2p electron from the ground level of Fe16+ is increased by 500 per cent and 100 per cent under an incident electron energy of 1500 and 10 000 eV, respectively. This results in the rate coefficient increasing by a factor of 18.5 at a temperature of 200 eV and density of 15.748 g cm−3.

Aluminum Hugoniot from model calculations including semicore electrons based on density functional theory

We present a method to obtain Hugoniot from model calculations based on density functional theory, and apply the method to aluminum Hugoniot. Technological advances have extended the experimental research of high energy density physics, and call for quantitative theoretical analysis. However, direct computation of Hugoniot from density functional theory is very difficult. We propose two step calculations of Hugoniot from density functional theory. The first step is molecular dynamics simulations with an ambient temperature for electrons. The second step is total energy calculations of a crystal with desired high temperatures for electrons and with the ambient temperature for electrons. We treated the semicore 2s and 2p electrons of aluminum as valence electrons only for the total energy calculations of the aluminum crystal. The aluminum Hugoniot from our model calculations is in excellent agreement with available experimental data and the previous density functional theory calculations in the literature.

Resistive grain boundary and double-diffused potential barrier formation for delayed dielectric relaxation in SrBi1.98La0.02Nb-TaO9 material

In present work, doping modified SrBi1.98La0.02Nb2-xTaxO9; x = 0.0–2.0 in steps of 0.5 (SBLNT) matrix is investigated for typical potential barrier formation yielding delayed dielectric relaxation and repair of weak ferroelectric character due to deterioration post microwave synthesis. Unit cell regularizes to tetragonal character on doping tantalum compared to dominant orthorhombic nature of undoped SrBi1.98La0.02Nb2O9 SBLN sample. Regular decrease in c-axis strain in the presence of fix lanthanum content is due to increased electrostatic repulsion along a-b plane on doping tantalum. Strong correlation between 4f-electrons of tantalum and intense sp3-hybridization between Ta(4f)-O(2p) electrons is discussed as a major cause for holding any unbound charge without participating in conduction. Complex impedance and modulus spectroscopy both confirm growth of highly resistive grain boundaries in sample with 50% tantalum doping. Poled and unpoled ferroelectric hysteresis loops for all samples indicate rise in ferroelectric hardness on increase in tantalum doping besides decreasing pore-size.

Direct double ionization of the Ar+ M shell by a single photon

Author(s): Muller, A; Kilcoyne, ALD; Phaneuf, RA; Holste, K; Schippers, S; Kheifets, AS | Abstract: Direct double ionization of the Ar+(3p-1) ion by a single photon is investigated both experimentally and theoretically. The photon-ion merged-beams technique was employed at the Advanced Light Source in Berkeley, USA, to measure absolute cross sections in the energy range from 60 to 150 eV. In this range, three contributions to the double ionization of Ar+ are to be expected: the removal of two 3p electrons, of a 3s and a 3p electron, and of two 3s electrons. Among the possible mechanisms leading to double ionization, the TS1 (two-step one) process dominates in the near-threshold region. In TS1, a photoelectron is ejected and, on its way out, knocks out a secondary electron. This two-step mechanism is treated theoretically by multiplying the calculated cross section for direct single photoionization of a given subshell with the calculated (e,2e) ionization probability for the ejected photoelectron to knock off a secondary electron. The calculated cross section is in very good agreement with the experiment.

Ab-initio investigations of electronic, optical, mechanical and thermal properties of Ca0.875Ba0.125Te

The ground-state properties and optical, mechanical, elastic and thermal properties of the Ca0.875Ba0.125Te alloy have been studied by using the full potential linearized augmented plane wave (FP-LAPW) scheme based on the density functional theory in the frame of generalized gradient approximation (GGA). In order to model Ca1-xBaxTe alloy, 16-atoms supercell of the type 2 × 2 × 2 is employed. The lattice structure of Ca0.875Ba0.125Te alloy is obtained by replacing one Ca atom by one Ba atom in the crystal lattice of CaTe. The charge density plot, electronic structure and density of states plots are made and discussed for the alloy. The lower valence band maxima (VBM) and the upper conduction band minima (CBM) of Ca0.875Ba0.125Te alloy is locaed at Γ point, ensuing in a direct band gap, whereas in case of parent element CaTe the nature of the band gap is indirect. The characteristic properties of Ca0.875Ba0.125Te alloy is dominated by Te 5p electrons (below the Fermi level) and Ba 4d and Ca 3d electrons (above the Fermi level).

Activation of CO2 on graphitic carbon nitride supported single-atom cobalt sites

Using solar energy to realize photoreduction of CO2 into valuable chemicals is a potential way to solve energy crisis and carbon cycle. Due to the extremely stable molecular configuration of CO2, activating CO2 molecule is the key and difficult step in the whole CO2 conversation process. In this work, we used density functional theory (DFT) to calculate the reaction pathways of CO2 to CO on pure g-C3N4 and single-atom cobalt (Co) modified g-C3N4. Theoretical calculation predicts that single-atom Co sites modified g-C3N4 (Co-CN) possess stronger CO2 adsorption ability and lower barrier of CO2 hydrogenation activation than pure g-C3N4. The strong interaction between Co 3d electrons and C 2p electrons of CO2 is the crucial factor to activate C = O bonds of CO2 molecule. Better CO2 adsorption and activation abilities also are proved in Co-CN by CO2 adsorption, temperature programmed desorption (TPD), and sensor tests. As a result, the optimal 1%Co-CN exhibits higher CO yield of 94.9 umol/g/h than pure g-C3N4 (0.25 umol/g/h). This work provides a new insight of the role of single-atom sites in CO2 reduction reactions.

Near L-edge Single and Multiple Photoionization of Doubly Charged Iron Ions

Abstract Using the photon–ion merged-beams technique at a synchrotron light source, we have measured relative cross sections for single and up to five-fold photoionization of Fe2+ ions in the energy range of 690–920 eV. This range contains thresholds and resonances associated with ionization and excitation of 2p and 2s electrons. Calculations were performed to simulate the total absorption spectra. The theoretical results show very good agreement with the experimental data, if overall energy shifts of up to 2.5 eV are applied to the calculated resonance positions and assumptions are made about the initial experimental population of the various levels of the Fe2+([Ar]3d 6) ground configuration. Furthermore, we performed extensive calculations of the Auger cascades that result when an electron is removed from the 2p subshell of Fe2+. These computations lead to a better agreement with the measured product-charge-state distributions as compared to earlier work. We conclude that the L-shell absorption features of low-charged iron ions are useful for identifying gas-phase iron in the interstellar medium and for discriminating against the various forms of condensed-phase iron bound to composite interstellar dust grains.

The Charge State of Pt in Binary Compounds and Synthetic Minerals Determined by X-ray Absorption Spectroscopy and Quantum Chemical Calculations

The binary synthetic compounds of Pt with chalcogens (O, S, Se, Te), pnictogens (As, Sb, Bi), and intermetallic compounds with Ga, In, and Sn of various stoichiometry were studied via X-ray absorption spectroscopy (XAS). The partial atomic charges of Pt in the compounds were computed using quantum chemical density functional theory (DFT) based methods: the Bader (QTAIM) method, and the density-derived electrostatic and chemical (DDEC6) approach. Strong positive correlations were established between the calculated partial atomic charges of Pt and the electronegativity (χ) of ligands. The partial charge of Pt in PtL2 compounds increases much sharply when the ligand electronegativity increases than the Pt partial charge in PtL compounds. The effect of the ligand-to-Pt atomic ratio on the calculated Pt partial charge depended on ligand electronegativity. The DDEC6 charge of Pt increases sharply with the growth of the number of ligands in PtSn (n = 1, 2; electronegativity χ(S) >> χ(Pt)), weakly depends on the phase composition in PtTen (n = 1, 2; χ(Te) is slightly lower than χ(Pt)), and decreases (becomes more negative) with increase of the ligand-to-Pt ratio in intermetallic compounds with electron donors (χ(L) < χ(Pt), L = Ga, In, Sn). According to XANES spectroscopy, the number of 5d (L2,3 absorption edges) and 6p (L1-edge) electrons at the Pt site decreased when ligand electronegativity increased in chalcogenides and pnictides groups. An increase of the ligand-to-Pt ratio resulted in the increase of the Pt L3-edge white line intensity and area in all studied compounds. In the case of chalcogenides and pnictides, this behavior was consistent with the electronegativity rule as it indicated a loss of Pt 5d electrons caused by the increase of the number of ligands, i.e., acceptors of electrons. However, in the case of ligands–electron donors (Te, Sn, Ga, In) this observation is in apparent contradiction with the electronegativity arguments as it indicates the increase of the number of Pt 5d-shell vacancies (holes) with the increase of the number of the ligands, for which the opposite trend is expected. This behavior can be explained in the framework of the charge compensation model. The loss of the Pt d-electrons in compounds with low ligand electronegativity (χ(Pt) > χ(L)) was overcompensated by the gain of the hybridized s-p electron density, which was confirmed by Pt L1 - edge spectra analysis. As a result, the total electron density at the Pt site followed the electronegativity rule, i.e., it increased with the growth of the number of the ligands-electron donors. The empirical correlations between the Pt partial atomic charges and parameters of XANES spectral features were used to identify the state of Pt in pyrite, and can be applied to determine the state of Pt in other ore minerals.