Ab Initio Density Functional Theory Research Articles

A DFT Characterization of Structural, Mechanical, and Thermodynamic Properties of Ag9In4 Binary Intermetallic Compound

The intermetallic compounds (IMCs) at the interface between the solder joint and metal bond pad/under bump metallization (UBM) exert a significant impact on the thermal–mechanical behavior of microelectronic packages because of their unique physical properties. In this study, a theoretical investigation of the physical properties, namely structural, mechanical, and thermodynamic properties, of the Ag9In4 IMC was conducted using ab initio density functional theory (DFT) calculations. The calculated equilibrium lattice constants were in good agreement with the literature experimental data. Furthermore, with the calculated elastic constants, we can derive the ductility and brittleness nature, elastic anisotropy, and direction-dependent elastic properties of Ag9In4 through several elastic indices, three-dimensional surface representation, and two-dimensional projections of elastic properties. The calculations inferred that the cubic Ag9In4 IMC confers structural and mechanical stability, ductility, relative low stiffness and hardness, and elastic anisotropy. Finally, the thermodynamic properties, i.e., Debye temperature, heat capacity, and minimum thermal conductivity, were also investigated. Evidently, the low-temperature heat capacity conforms to the Debye heat capacity theory and the high-temperature one complies with the classical Dulong–Petit law.

J=0 nonmagnetic insulating state in K2OsX6 (X=F,Cl,andBr)

In $4d/5d$ transition-metal systems, many interesting physical properties arise from the interplay of bandwidth, electronic correlations, and spin-orbit interactions. Here, using {\it ab initio} density functional theory, we systematically study the double-perovskite-like system K$_2$Os$X_6$ (X = F, Cl, and Br) with a $5d^4$ electronic configuration. Our main result is that the $J = 0$ nonmagnetic insulating state develops in this system, induced by strong spin-orbital coupling. Specifically, the well-separated Os$X_6$ octahedra lead to the cubic crystal-field limit and result in dramatically decreasing hoppings in nearest neighbor Os-Os sites. In this case, the three degenerate $t_{2g}$ orbitals are reconstructed into two ``effective'' $j_{\rm eff}$ ($j_{\rm eff} = 1/2$ and $j_{\rm eff} = 3/2$ states) states separated by the strong SOC, opening a gap with four electrons occupying the $j_{\rm eff} = 3/2$ orbitals. Furthermore, the hybridization between the Os $5d$ orbitals and the $X$ ($X$ = F, Cl, and Br) $p$ orbitals increases from F to Br, leading the electrons in K$_2$OsF$_6$ to be more localized than in K$_2$OsCl$_6$ and K$_2$OsBr$_6$, resulting in a smaller bandwidth for K$_2$OsF$_6$ than in the Cl- or Br- cases. Our results provide guidance to experimentalists and theorists working on this interesting family of osmium halides.

Combined experimental and theoretical study of hydrostatic He-gas pressure effects in α−RuCl3

We report a detailed experimental and theoretical study on the effect of hydrostatic pressure on the structural and magnetic aspects of the layered honeycomb antiferromagent $\alpha$-RuCl$_{3}$. Magnetic susceptibility measurements performed under almost ideal hydrostatic-pressure conditions yield that the phase transition to zigzag-type antiferromagnetic order at $T_N$ = 7.3 K can be rapidly suppressed to about 6.1 K. A further suppression with increasing pressure is impeded due to the occurrence of a pressure-induced structural transition at $p \geq$ 104 MPa, accompanied by a strong dimerization of Ru-Ru bonds, which gives rise to a collapse of the magnetic susceptibility. Whereas the dimerization transition is strongly first order, as reflected by large discontinuous changes in $\chi$ and pronounced hysteresis effects, the magnetic transition under varying pressure and magnetic field also reveals indications for a weakly first-order transition. We assign this observation to a strong magnetoelastic coupling in this system. Measurements of $\chi$ under varying pressure in the paramagnetic regime ($T > T_N$) and before dimerization ($p <$ 100 MPa) reveal a considerable increase of $\chi$ with pressure. These experimental observations are consistent with the results of ab-initio Density Functional Theory (DFT) calculations on the pressure-dependent structure and the corresponding pressure-dependent magnetic model. Comparative susceptibility measurements on a second crystal showing two consecutive magnetic transitions instead of one, indicating the influence of stacking faults. Using different temperature-pressure protocols the effect of these stacking faults can be temporarily overcome, transforming the magnetic state from a multiple-$T_N$ into a single-$T_N$ state.

Ab Initio Atomistic Simulations of Ca‐Perovskite Melting

AbstractMelting curves of Ca‐perovskite (pure CaSiO3) were determined by ab initio density functional theory, using two solid‐liquid coexistence methods and two free energy approaches, in the form of thermodynamic integration and two‐phase thermodynamics. The melting curves based on the solid‐liquid coexistence methods and thermodynamic integration rise steeply from 2000 K at 14 GPa to 7000 K at 136 GPa. The melting temperature at 136 GPa is 1400 K higher than previous ab initio predictions. The high thermal stability of Ca‐perovskite is linked to its high‐symmetry isometric structure and consistent with experiments, demonstrating that Ca‐perovskite is the most refractory phase in basaltic compositions in the lower mantle pressure range. The steep dT/dp slope of the melting curve also shows that the Ca‐perovskite liquidus field expands relative to those of bridgmanite and silica with increasing pressure, in agreement with experimental evidence from simple and complex systems.

Gap opening at the Dirac point of graphene on Cu(111): Hybridization versus sublattice symmetry breaking

Gap opening at the Dirac point of graphene on metals has been ascribed to hybridization, sublattice symmetry breaking, or combination of both. However, how and what to extent gap opens under the influence of these effects has been a question in controversy. In this paper, we explore gap opening in graphene on metals using a simple tight-binding (TB) model for a hypothetical heterobilayer, which mimics a system of graphene/metal. A theoretical framework for the gap opening is obtained using exact solutions to the TB-model Hamiltonian through small-parameter expansions. This result is formally similar to that obtained for an ad hoc model graphene with pseudospin asymmetry originating from the spin-orbit proximity effect, which is not considered in the present analysis but is taken over by more substantial effect of orbital-hybridization indispensable for the gap opening in graphene on metals. The present result reveals, for the first time, that sublattice symmetry breaking and hybridization asymmetry compensate each other and disruptively contribute to the gap opening at the Dirac point of graphene on metals. The picture is in marked contrast to the previous ones such as hybridization-induced sublattice symmetry breaking or an additive model, in which sublattice symmetry breaking and hybridization additively contribute to the gap opening. The results obtained by the present TB-model analysis are successfully used to interpret the results of ab initio density functional theory (DFT) calculations for graphene/Cu(111) and thereby, for the first time, to discriminate sublattice symmetry breaking and hybridization asymmetry explicitly. We also find, through these analyses of the DFT calculations, that hybridization asymmetry dominates gap opening at the Dirac point for large graphene-substrate separations (d), while sublattice symmetry breaking is dominant for small d, and both are balanced with each other in between to yield a small gap, which is practically closed in the system of graphene/Cu(111). Another point revealed by those analyses is that sublattice symmetry breaking and hybridization are necessarily in combination with each other and are together large or small depending on interface structures. All these results are expected to provide a useful insight into gap opening at the Dirac point of graphene in other systems including graphene/metal superstructures resulting from lattice mismatch, misorientation, intercalation, or other structural modifications.

Effect of localization on photoluminescence and zero-field splitting of silicon color centers

The study of defect centers in silicon has been recently reinvigorated by their potential applications in optical quantum information processing. A number of silicon defect centers emit single photons in the telecommunication $O$-band, making them promising building blocks for quantum networks between computing nodes. The two-carbon G-center, self-interstitial W-center, and spin-$1/2$ T-center are the most intensively studied silicon defect centers, yet despite this, there is no consensus on the precise configurations of defect atoms in these centers, and their electronic structures remain ambiguous. Here we employ ab initio density functional theory to characterize these defect centers, providing insight into the relaxed structures, band structures, and photoluminescence spectra, which are compared to experimental results. Motivation is provided for how these properties are intimately related to the localization of electronic states in the defect centers. In particular, we present the calculation of the zero-field splitting for the excited triplet state of the G-center defect as the structure is linearly interpolated from the A-configuration to the B-configuration, showing a sudden increase in the magnitude of the ${D}_{zz}$ component of the zero-field-splitting tensor. By performing projections onto the local orbital states of the defect, we analyze this transition in terms of the symmetry and bonding character of the G-center defect, which sheds light on its potential application as a spin-photon interface.

Electro-Design of Bimetallic PdTe Electrocatalyst for Ethanol Oxidation: Combined Experimental Approach and Ab Initio Density Functional Theory (DFT)-Based Study.

An alternative electrosynthesis of PdTe, using the electrochemical atomic layer deposition (E-ALD) method, is reported. The cyclic voltammetry technique was used to analyze Au substrate in copper (Cu2+), and a tellurous (Te4+) solution was used to identify UPDs and set the E-ALD cycle program. Results obtained using atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques reveal the nanometer-sized flat morphology of the systems, indicating the epitaxial characteristics of Pd and PdTe nanofilms. The effect of the Pd:Te ratio on the crystalline structure, electronic properties, and magnetic properties was investigated using a combination of density functional theory (DFT) and X-ray diffraction techniques. Te-containing electrocatalysts showed improved peak current response and negative onset potential toward ethanol oxidation (5 mA; −0.49 V) than Pd (2.0 mA; −0.3 V). Moreover, DFT ab initio calculation results obtained when the effect of Te content on oxygen adsorption was studied revealed that the d-band center shifted relative to the Fermi level: −1.83 eV, −1.98 eV, and −2.14 eV for Pd, Pd3Te, and Pd3Te2, respectively. The results signify the weakening of the CO-like species and the improvement in the PdTe catalytic activity. Thus, the electronic and geometric effects are the descriptors of Pd3Te2 activity. The results suggest that Pd2Te2 is a potential candidate electrocatalyst that can be used for the fabrication of ethanol fuel cells.

Atomistic Insight into the Epitaxial Growth Mechanism of Single-Crystal Two-Dimensional Transition-Metal Dichalcogenides on Au(111) Substrate.

A mechanistic understanding of interactions between atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDs) and their growth substrates is important for achieving the unidirectional alignment of nuclei and seamless stitching of 2D TMD domains and thus 2D wafers. In this work, we conduct a cross-sectional scanning transmission electron microscopy (STEM) study to investigate the atomic-scale nucleation and early stage growth behaviors of chemical vapor deposited monolayer (ML-) MoS2 and molecular beam epitaxy ML-MoSe2 on a Au(111) substrate. Statistical analysis reveals the majority of as-grown domains, i.e., ∼88% for MoS2 and 90% for MoSe2, nucleate on surface terraces, with the rest (i.e., ∼12% for MoS2 and 10% for MoSe2) on surface steps. Moreover, within the latter case, step-associated nucleation, ∼64% of them are terminated with a Mo-zigzag edge in connection with the Au surface steps, with the rest (∼36%) being S-zigzag edges. In conjunction with ab initio density functional theory calculations, the results confirm that van der Waals epitaxy, rather than the surface step guided epitaxy, plays deterministic roles for the realization of unidirectional ML-MoS2 (MoSe2) domains on a Au(111) substrate. In contrast, surface steps, particularly their step height, are mainly responsible for the integrity and thickness of MoS2/MoSe2 films. In detail, it is found that the lateral growth of monolayer thick MoS2/MoSe2 domains only proceeds across mono-Au-atom high surface steps (∼2.4 Å), but fail for higher ones (bi-Au atom step and higher) during the growth. Our cross-sectional STEM study also confirms the existence of considerable compressive residual strain that reaches ∼3.0% for ML-MoS2/MoSe2 domains on Au(111). The present study aims to understand the growth mechanism of 2D TMD wafers.

Knee structure in the laser-intensity dependence of harmonic generation for graphene

We investigate the high-order harmonic generations (HHGs) of graphene irradiated by linearly polarized lasers with intensities in a wide range from $10^{8}$ W/cm$^2$ to $10^{13}$ W/cm$^2$. We find a striking knee structure in the laser intensity dependence of HHGs, which consists of a linear growth regime, followed by a plateau of the saturated HHGs, and then a transition to a nonlinear growth. The knee structure is rather universal for the varied harmonic orders and has been certificated by the calculations of two-band density-matrix equations as well as the \textit{ab initio} calculations of time-dependent density functional theory. Based on the two-band model, we reveal the underlying mechanisms: The behavior of linear growth can be depicted analytically by the perturbative theory of optical conductivity; While, the plateau of saturated HHGs and the transition to a nonlinear growth are caused by the quantum destructive interference and constructive interference of harmonics generated by the electrons corresponding to the lattice momentums around Dirac points and M points in Brillouin zone, respectively. In particular, we find that tuning Fermi energy can effectively alter the knee structure while the profile of the knee structure is not sensitive to the temperature. Our calculations of the third-order harmonic vs. tuning Fermi energy are compared with recent experiment showing a good agreement. Our predicted knee structure and its associated properties are observable with the current experimental techniques.

In situ characterization of vacancy ordering in Ge-Sb-Te phase-change memory alloys

Tailoring the degree of structural disorder in Ge-Sb-Te alloys is important for the development of non-volatile phase-change memory and neuro-inspired computing. Upon crystallization from the amorphous phase, these alloys form a cubic rocksalt-like structure with a high content of intrinsic vacancies. Further thermal annealing results in a gradual structural transition towards a layered structure and an insulator-to-metal transition. In this work, we elucidate the atomic-level details of the structural transition in crystalline GeSb2Te4 by in situ high-resolution transmission electron microscopy experiments and ab initio density functional theory calculations, providing a comprehensive real-time and real-space view of the vacancy ordering process. We also discuss the impact of vacancy ordering on altering the electronic and optical properties of GeSb2Te4, which is relevant to multilevel storage applications. The phase evolution paths in Ge-Sb-Te alloys and Sb2Te3 are illustrated using a summary diagram, which serves as a guide for designing phase-change memory devices.

Experimental and DFT studies on spinel NiMn2O4 flower derived from bimetallic MOF as an efficient electrode for next-generation supercapacitor

Metal-organic frameworks (MOF) have recently emerged as an intriguing template for developing morphologically pre-designed metal oxide nanostructures. MOFs offer excellent control over morphology, extremely high porosity and large surface area, which is highly beneficial for supercapacitor electrode applications. We report the synthesis of bimetallic MOF-derived Nickel Manganese oxide for an electrode in supercapacitor by an efficient solvothermal and subsequent calcination route. The physical characterization was carried out by X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TGA) and Bruner-Emmert-Teller (BET). We performed the cyclic voltammetry (CV), chronopotentiometry (CP), and electronic impedance spectroscopy (EIS) test in a 1 M KOH electrolyte to examine the electrochemical characteristics of the prepared samples. NiMn2O4 electrode material revealed high specific capacitance of 1387 F/g at 1 A/g current density and prominent cycle life (80% capacitance retention after 6500 cycles) and the porous structure of the material has a good BET surface area of 84.3 m2/g. Further, we performed spin-polarized ab-initio density functional theory calculations to study the structural, electronic, and magnetic properties of the spinel NiMn2O4 structure. Our calculated results are close to the experimentally determined structural parameters, and the enthalpy of formation confirms the thermodynamical stability of the spinel structure with ΔHF = −1.6 eV/atom. The orbital projected electronic structure is further investigated to understand the contribution of elements near the Fermi region, which paves the way for further understanding of the distribution of electrons at a particular energy interval of our system. The present findings will aid in fabricating the bimetallic MOF-derived metal oxide nanostructures for the next-generation supercapacitors.

Towards the Growth of Hexagonal Boron Nitride on Ge(001)/Si Substrates by Chemical Vapor Deposition.

The growth of hexagonal boron nitride (hBN) on epitaxial Ge(001)/Si substrates via high-vacuum chemical vapor deposition from borazine is investigated for the first time in a systematic manner. The influences of the process pressure and growth temperature in the range of 10−7–10−3 mbar and 900–980 °C, respectively, are evaluated with respect to morphology, growth rate, and crystalline quality of the hBN films. At 900 °C, nanocrystalline hBN films with a lateral crystallite size of ~2–3 nm are obtained and confirmed by high-resolution transmission electron microscopy images. X-ray photoelectron spectroscopy confirms an atomic N:B ratio of 1 ± 0.1. A three-dimensional growth mode is observed by atomic force microscopy. Increasing the process pressure in the reactor mainly affects the growth rate, with only slight effects on crystalline quality and none on the principle growth mode. Growth of hBN at 980 °C increases the average crystallite size and leads to the formation of 3–10 well-oriented, vertically stacked layers of hBN on the Ge surface. Exploratory ab initio density functional theory simulations indicate that hBN edges are saturated by hydrogen, and it is proposed that partial de-saturation by H radicals produced on hot parts of the set-up is responsible for the growth.

Bringing the promises of microreactors and gold catalysis to lignocellulosic biomass valorization: A study on oxidative transformation of furfural

Valorization of lignocellulosic biomass is a key to a sustainable chemical production industry. Furfural has been recognized as a major biomass-derived platform compound and a precursor of various value-added chemicals, including alkyl furoates with a wide range of applications. The conventional production of alkyl furoate utilizes concentrated acids and strong oxidants, making it an environmentally taxing process. A greener alternative is the one-pot direct conversion of furfural to alkyl furoate in an alcohol medium through oxidative esterification using molecular oxygen. However, the explosive mixtures of O2 and alcohols pose a major challenge to this process. To circumvent this issue, for the first time in the literature, we employed a catalytic microchannel reactor that enabled us to carry out the reaction over a wide range of reaction conditions, including the conventionally explosive regions. The conversion of furfural to methyl 2-furoate (MF) was carried out over a silica-supported Au catalyst coated on the inner wall of a microcapillary. A thorough experimental investigation of the reaction was conducted to obtain kinetic information while accounting for possible mass transfer effects on the process. The barely addressed mechanism of gold-assisted oxidative esterification is then investigated, taking advantage of ab initio density functional theory to examine plausible mechanisms. Experimental and computational evidence suggested that surface regeneration by O2 and decomposition of methanol to methoxy species are the crucial steps in the reaction pathway, while furfural was found to have no involvement in the rate-determining step. This work attempts to provide further insights into the reaction engineering and mechanistic aspects of furfural oxidative esterification to potentially contribute to rational catalyst design and process development.

Implications of electron and hole doping on the magnetic properties of spin–orbit entangled Ca4IrO6 from DFT calculations

We investigate the electronic structure and magnetic properties of a Jeff=1/2 iridate Ca4IrO6 and the implications of doping electrons and holes using ab initio density functional theory. Our calculations considering spin–orbit interaction reveal that although the Mott-insulating parent compound transforms into a conductor upon doping, antiferromagnetism sustains in the doped system, albeit with a grossly noncollinear arrangement of the spins. We find a strong spin–orbit interaction and magneto-crystalline anisotropy, causing frustration in the system, possibly leading to the highly noncollinear arrangement of spins upon non-magnetic doping. Our results may be important from the viewpoint of spintronics using iridates or other 5d materials.

Disentangling the electronic structure of an adsorbed graphene nanoring by scanning tunneling microscopy

Graphene nanorings are promising model structures to realize persistent ring currents and Aharonov–Bohm effect at the single molecular level. To investigate such intriguing effects, precise molecular characterization is crucial. Here, we combine low-temperature scanning tunneling imaging and spectroscopy with CO functionalized tips and algorithmic data analysis to investigate the electronic structure of the molecular cycloarene C108 (graphene nanoring) adsorbed on a Au(111) surface. We demonstrate that CO functionalized tips enhance the visibility of molecular resonances, both in differential conductance spectra and in real-space topographic images. Comparing our experimental data with ab-initio density functional theory reveals a remarkably precise agreement of the molecular orbitals and enables us to disentangle close-lying molecular states only separated by 50 meV at an energy of 2 eV below the Fermi level. We propose this combination of techniques as a promising new route for a precise electronic characterization of complex molecules and other physical properties which have electronic resonances in the tip-sample junction.

Modeling the temporal evolution and stability of thin evaporating films for wafer surface processing.

The interaction of thin evaporating fluid films with solids is studied using the example of water on LiTaO3 (LTO). Adsorption energies are computed by ab initio density functional theory (DFT) and used to calculate the Gibbs free energy of adsorption of water on LTO. Integrating the disjoining pressure, consisting of molecular and structural components, with respect to film thickness gives an expression for the Gibbs free energy. In this way, parameters for the disjoining pressure can be calculated by fitting its integral to the Gibbs free energy computed by ab initio DFT. A combination of literature-known models for spin drying and evaporation is utilized to describe the temporal evolution of the water layer. The vapor above the water layer is modeled by diffusion and a mass balance is applied at the water-air interface. For thick initial layers, an analytical approximation is derived which only depends on fluid and ambient conditions but not on the substrate properties.

Theoretical investigations on the excited-state intramolecular proton transfer in the solvated 2-hydroxy-1-naphthaldehyde carbohydrazone

Abstract The vast applications of 2-hydroxy-1-naphthaldehyde-derived systems in the sensors originate from their unusual excited-state intramolecular proton transfer (ESIPT) fluorescence in the molecules. The mechanism of ESIPT fluorescence in the solvated 2-hydroxy-1-naphthaldehyde carbohydrazone (HNLSC) system was investigated by ab initio time-dependent density functional theory (TDDFT) calculation. The solvation stabilized both ground state and excited state in the enol form, and the medium intramolecular interaction ensured the bond break, bond-forming and proton transfer in the conversion from excited enol form to keto form. ESIPT reaction from the enol form to the keto form had a low barrier of 2.54 kcal mol−1 in the cyclohexane solvation, and all the calculated emission was consistent with the experimental findings. Moreover, the disaggregation of excited enol form was favoured instead of the IPT conversion to keto form, vanishing the specific ESIPT pathway in the protic surroundings. Our research can give a meaningful insight into the two kinds of fluorescence spectroscopy in the HNISC system found by experimental measurement and be potential guidance to the application of 2-hydroxy-1-naphthaldehyde-derived systems in the development of new-type sensors, nonlinear optical materials and biochemical probes.

Multilevel Computational Studies Reveal the Importance of Axial Ligand for Oxygen Reduction Reaction on Fe-N-C Materials.

The systematic improvement of Fe-N-C materials for fuel cell applications has proven challenging, due in part to an incomplete atomistic understanding of the oxygen reduction reaction (ORR) under electrochemical conditions. Herein, a multilevel computational approach, which combines ab initio molecular dynamics simulations and constant potential density functional theory calculations, is used to assess proton-coupled electron transfer (PCET) processes and adsorption thermodynamics of key ORR intermediates. These calculations indicate that the potential-limiting step for ORR on Fe-N-C materials is the formation of the FeIII-OOH intermediate. They also show that an active site model with a water molecule axially ligated to the iron center throughout the catalytic cycle produces results that are consistent with the experimental measurements. In particular, reliable prediction of the ORR onset potential and the Fe(III/II) redox potential associated with the conversion of FeIII-OH to FeII and desorbed H2O requires an axial H2O co-adsorbed to the iron center. The observation of a five-coordinate rather than four-coordinate active site has significant implications for the thermodynamics and mechanism of ORR. These findings highlight the importance of solvent-substrate interactions and surface charge effects for understanding the PCET reaction mechanisms and transition-metal redox couples under realistic electrochemical conditions.

Active Surface Structure of SnO2 Catalysts for CO2 Reduction Revealed by Ab Initio Simulations

Tin oxide (SnO2) is an efficient catalyst for the CO2 reduction reaction (CO2RR) to formic acid; however, the understanding of the SnO2 surface structure under working electrocatalytic conditions and the nature of catalytically active sites is a current matter of debate. Here, we employ ab initio density functional theory calculations to investigate how the selectivity and reactivity of SnO2 surfaces toward the CO2RR change at varying surface stoichiometry (i.e., reduction degree). Our results show that SnO2(110) surfaces are not catalytically active for the CO2RR or hydrogen evolution reaction, but rather they reduce under an applied external bias, originating surface structures exposing few metal tin layers, which are responsible for formic acid selectivity.

Spectroscopic investigations, ab-initio DFT calculations, molecular docking and in-vitro assay studies of novel oxovanadium(V)chalcone complexes as potential antidiabetic agents

A series of four novel oxovanadium(V)chalcone complexes ([VO(LI-IV)2Cl]; where HLI=1-(2-Hydroxy-phenyl)-3-phenyl-propenone, HLII=1-(1-Hydroxy-naphthalen-2-yl)-3-phenyl-propenone, HLIII = 1-(2-Amino-phenyl)-3-phenyl-propenone, HLIV = 4-Hydroxy-6-methyl-3-(3-phenyl-acryloyl)-pyran-2-one) were designed and synthesized by performing chemical reaction between VOCl3 and respective chalcone derivatives in 1:2 molar ratio. Their formation as well as chemical structures were confirmed by FTIR, UV-Visible, 1H-NMR, SEM, EDS, and mass spectrometry spectroscopic techniques. The geometry of the synthesized complexes was purposed to be octahedral on the basis of the characterization. Further computational and structural parameters of the synthesized complexes were determined in order to establish their thermodynamic stability/chemical reactivity of the synthesized complexes. Density Functional Theory (DFT) method was employed to calculate the molecular geometry and vibrational frequencies of the synthesized complexes using B3LYP hybrid functional at 6-31G* level of basis set. Further, Spartan'20 V1.0.0 program package was used to calculate the 1H-NMR spectra with (DFT/ B3LYP) in the gaseous phase to validate the structure of oxovanadium(V) complexes. The experimentally obtained results were found to be well correlated with theoretical results with a correlation value > 0.96. Global reactivity descriptors helps to explain the bioactivity of complexes hence, were calculated from the HOMO-LUMO energies. The enzymatic assay experiments indicated that all the four synthesized complexes have significant to moderate inhibition potential against α-glucosidase, and α-amylase enzymes. Among all the oxovanadium(V)chalcone complexes, complex 4showed excellent and superior inhibition potency almost equivalent to the commercially available Acarbose drug and even better in case of α-amylase. The observed IC50 value of complex 4 for the inhibition of α-amylase and α-glucosidase was calculated to be 16.36 µg/mL and 57.27 µg/mL, respectively. The Kinetic parameters calculated from the Lineweaver-Burk plot showed that complex 4 were uncompetitive and mixed inhibitor of α-amylase and α-glucosidase respectively. Thereafter,the antiradical activity of synthesized vanadium(V)chalcone complexes was assessed with the help of DPPH radical scavenging assay. The results demonstrated that all the complexes were remarkable free radical scavengers for the DPPH. The complex 1 was observed to be best among them with the 0.03 µg/mL IC50 value. The AutoDockTools-1.5.6 software was used to examine structure-activity relationship and the binding interactions between oxovanadium(V) complexes and protein target alpha-amylase, alpha-glucosidase, and Myeloperoxidase respectively. The in-vitro as well as in-silico biological activity studies showed significant and major improvements after complexation of chalcone derivatives with vanadium oxychloride (VOCl3). Thus, oxovanadium(V)chalcone complexes were found to be potent inhibitors of the α-glucosidase and α-amylase enzyme.