Imaginary Part Of Dielectric Function Research Articles

The band offset, Half-metallic and optical behavior in the CrSb/KCl [0 0 1] interface: By DFT calculation

Half-metallic, optical and band offsets properties of CrSb/KCl [0 0 1] interface have been calculated within the density functional theory (DFT) framework using FP-LAPW+lo method. We found that the CrSb/KCl [0 0 1] heterojunction retain perfect half-metallic character with 0.95 eV and 1.5 eV spin flip gap at spin down, using GGA and mbj approximations, respectively. The 0.03 meV electrostatic potential gap between CrSb film and KCl substrate demonstrate that the CrSb film is the good spin electron source for injection to the KCl film. The optical coefficients such as real and imaginary parts of dielectric function, reflection, refraction, extinction and energy loss function indices have been shown the good optical response in the visible area. The band offset parameters of CrSb/KCl [0 0 1] interface are of the type-I model with great amount of ФB and χ potentials.

Structural, electronic and optical properties of Ca3Bi2: First-principles investigation

In this work by applying first principles calculations structural, electronic and optical properties of Ca3Bi2 compound in hexagonal and cubic phases are studied within the framework of the density functional theory using the full potential linearized augmented plane wave (FP-LAPW) approach. According to our study band gap for Ca3Bi2 in hexagonal phase are 0.47, 0.96 and 1 eV within the PBE-GGA, EV-GGA and mBJ-GGA, respectively. The corresponding values for cubic phase are 1.24, 2.08 and 2.14 eV, respectively. The effects of hydrostatic pressure on the behavior of the electronic properties such as band gap, valence bandwidths and anti-symmetry gap are investigated. It is found that the hydrostatic pressure increases the band widths of all bands below the Fermi energy while it decreases the band gap and the anti-symmetry gap. In our calculations, the dielectric tensor is derived within the random phase approximation (RPA). The first absorption peak in imaginary part of dielectric function for both phases is located in the energy range 2.0–2.5 eV which are beneficial to practical applications in optoelectronic devices in the visible spectral range. For instance, hexagonal phase of Ca3Bi2 with a band gap around 1 eV can be applied for photovoltaic application and cubic phase with a band gap of 2 eV can be used for water splitting application. Moreover, we found the optical spectra of hexagonal phase are anisotropic along E||x and E||z.

Effect of oxygen vacancy on Sb3+, Nb3+ and V3+ doped KTaO3 compounds

In this study, the structural, electronic and optical properties of undoped and Sb3+, Nb3+ and V3+ doped defective KTaO3 compounds are investigated using the full potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT). We have calculated bond length, band gap energies and density of states for all compounds. For undoped KTaO3 compound, the lattice parameter and bond length of Ta-O are found 4.0301 Å and 2.0150 Å, respectively. Besides, all optical parameters (real and imaginary parts of dielectric function, absorption coefficient, reflectivity and refraction index) are calculated. The refractive indices and percentage reflection increase with the doping and defect. This theoretical paper motivates further future studies.

Effect of uni-axial and bi-axial strains and vertical electric field on free standing buckled germanene

In this work, the effects of small uni-axial and bi-axial strains and vertical electric field on the band dispersion and dielectric response of germanene are studied by density functional theory. The results show that by applying the vertical electric field a small band gap at the K point is opened in germanene. The created band gap increases with electric field. The vertical electric field only affects the optical spectra in the low energy range below 1 eV. The band structure of germanene under small biaxial strain maintains the feature of bands near the K point without applying the strain, including a pair of two linear dispersive bands crossing at the Fermi level and the Dirac point position. The CBM at the Γ point moves downward as the biaxial strain increases. By applying the small uniaxial strain, a direct gap at K point is observed and the value of band gap increases with increasing of strain. Imaginary part of dielectric function shows that the inter-band transitions are red-shifted for uni- and bi-axial tensile strains and are blue shifted for uni- and bi-axial compressive strains. The predicted tunability of the band gap and dielectric response by applying the strain and electric field may leads to a wide range of applications of germanene in electronic and optoelectronic devices.

First-principles DFT calculations of the electronic structure and optical properties of TlInGe2Se6, a prospective NLO material

We present results of first-principles density functional theory (DFT) calculations of total density of states (DOS) and partial densities of states (PDOSs) of novel quaternary selenide TlInGe2Se6, a promising nonlinear optical (NLO) material. The calculations are performed employing the augmented plane wave + local orbitals (APW + lo) method as implemented in the WIEN2k package. The DOS and PDOSs curves reveal the significant hybridization between the electronic states of atoms composing the TlInGe2Se6 compound and forming its chemical bonds. The present DFT calculations indicate that the Se 4p states are the principal contributors to the valence band of TlInGe2Se6, making the main contributions to the top and upper portion of the band, while contributions of the Ge 4p and In 5s states dominate in its central portion and bottom, respectively. Furthermore, contributions of the unoccupied Ge 4s states dominate at the bottom of the conduction band of the compound under study. The calculated electronic bands along broad selected symmetry paths manifest that the conduction band minimum and the valence band maximum are positioned at the L point of the first Brillouin zone resulting in a direct band gap of the compound under consideration. The main optical constants, namely dispersion of the absorption coefficient, real and imaginary parts of dielectric function, electron energy-loss spectrum, refractive index, extinction coefficient and optical reflectivity are studied for TlInGe2Se6 based on the APW + lo calculations.

Optoelectronic performances on different structures of Al‐doped ZnO

AbstractZnO films and Al‐doped ZnO (AZO) films were deposited on p‐Si substrate by magnetron sputtering to investigate its chemical composition, structural and photoelectric properties. XRD and FTIR show that Al ions can enter into the substitutional and interstitial site of ZnO crystal, and O atoms in AZO films are more abundant. Three different structures of Al‐doped ZnO (substitutional Al, interstitial Al, and O‐rich Al‐doped ZnO) were built using first‐principles method based on experimental results, charge density difference, and density of States (DOS) illustrate that there are strong ionic interactions between Al and O atoms in substitutional Al‐doped ZnO, moreover, substitutional and interstitial Al doping both are beneficial to N type, but oxygen‐enriched ZnO is not conducive to N type. Furthermore, the optical properties of 3 different Al‐doped ZnO structures were investigated respectively. Compared with pure ZnO, the real and imaginary part of dielectric function of O‐rich and interstitial Al have a significant increase and move to lower energy (red shift), the reflectivity of O‐rich is 3 times of pure ZnO and substitutional Al‐doped ZnO. The results are hoped to be helpful to study AZO thin film and predict the properties of Al‐doped ZnO.

Ab initio Modeling of Elastic and Optical Properties of Sb and Bi Sesquioxides

First-principle calculations performed the structural, mechanical, electronic, and optical properties of Sb2O3 and Bi2O3 compounds in monoclinic (claudetite and α-Bi2O3) and orthorhombic (valentinite) structures. Local density approximation has been used for modeling exchange-correlation effects. The lattice parameters, bulk modulus, and the first derivate of bulk modulus (to fit to the Murnaghan’s equation of state) of considered compounds have been calculated. The second-order elastic constants have been calculated, and the other related quantities have also been estimated in the present work. The electronic bands structures and the partial densities of states corresponding to the band structures are presented and analyzed. The real and imaginary parts of dielectric functions and energy-loss function are calculated. Our structural estimation and some other results are in agreement with the available experimental and theoretical data.

The effect of vacancies on the optical properties and plasmonic states of zinc oxide: A first-principle study

We study structural and optical properties of ZnO film prepared by pulsed laser deposition. The film was characterized by x-ray diffraction and UV–visible spectroscopies. We find that the as-grown film is mostly amorphous. After hydrogen-annealing treatment, the film is crystallized with lattice parameters of a = 3.241 Å and c = 5.203 Å. From UV–visible spectra, the low absorption edges of 1.44 and 1.43 eV are observed in the as-grown and annealed films, respectively, suggested to be promoted by some vacancies. Then, the generalized gradient approximation method is used to calculate electronic and optical properties of ZnO0.94, and Zn0.94O systems as the possible models of the annealed film. Properties ZnO is also calculated as the reference. Bandgaps of 0.75 and 1.73 eV are obtained for ZnO and ZnO0.94, respectively. The larger bandgap of ZnO0.94 is caused by the increase of Fermi level induced by Zn 4s electrons, leading to the n-type semiconducting behaviour. On the other hand, Zn0.94O exhibits the p-type metallic behaviour caused by the decrease of Fermi level induced by O 2p electrons with a minimum interband transition (ΔE) of 0.95 eV. Then, a shift of ΔE is applied in the optical properties calculation for approaching the experimental results. From the imaginary part of dielectric function (ε2(E)) for xy plane, ΔE of ZnO and ZnO0.94 systems are 3.30 and 4.10 eV, respectively. The optical dichroism of ZnO0.94 is smaller than that of ZnO. On the other hand, ΔE of Zn0.94O is 1.80 eV based on ε2(E) for z axis indicating the optical dichroism flip by the Zn vacancy in ZnO. The low absorption edge of the annealed film is promoted by the Zn vacancy. Furthermore, plasmonic-state energy levels in ZnO can be tuned by the O or Zn vacancies. This study shows the essential properties of ZnO for potential high-energy plasmonic device applications.

Optical study of cubic, and orthorhombic structures of XCaCl3 (X = K, Rb) compounds: Comparative Ab initio calculations

The study predicts the optical properties of cubic and orthorhombic structures of XCaCl3 (X = K, Rb) perovskite compounds through electronic band structure computation within the framework of density functional theory (DFT). The ground state functions are computed employing full potential linearized augmented plane wave (FP-LAPW) method. Improved band gap values and the electronic as well as optical properties were calculated by Tran and Blaha modified Becke–Johnson (mBJ) functional. The studied compounds’ density of states reveals that Cl-p states dominate the valence band. To understand the optical properties, and predicting the optically isotropic nature of these materials, the real and imaginary parts of dielectric function, refractive index, absorption coefficient, and energy loss spectra are plotted. The present study shows a great potential utilization in ceramic scintillators.

Electronic structures and optical properties of Mn-doped LiCaN new diluted magnetic semiconductors

Using the first-principle density functional theory based on the full potential linearized augmented plane wave method, the geometric structures of new diluted magnetic semiconductor Li1± y (Ca1− x Mn x )N ( x =0, 0.125; y =0, 0.125) were optimized. The electronic structures and optical properties were calculated and discussed in detail. The results show that the magnetic and electrical properties of the doped system can be separately regulated by Mn doping and Li off-stoichiometry. When Mn doped in the system, the electrons of the Mn 3d split into triply degenerate t 2g and double degenerate e g energy levels. Meanwhile, the Mn 3d states hybridize with Ca 4s and N 2p states, leads to the systems display half-metallic ferromagnetism. In Li excess and insufficient compounds, the band gaps and magnetic moments decrease, while the Curie temperature and electrical conductivity increase, and they exhibit 100% spin injection. In addition, the half-metallicity of Li insufficient system enhances significantly. In Li excess compound, Jahn-Teller effect leads to the highest Curie temperature and the lowest formation energy. Comparing optical properties indicates that the imaginary part of dielectric function, complex refractive index function, optical absorption function and the imaginary part of photoconductivity are all affected by Li stoichiometry. The energy loss functions of the doped systems show obvious blue-shift effect and much stronger plasma resonant frequency, and the oscillating range of plasma is wider in Li excess and insufficient compounds.

The effect of replacing pnictogen elements on the physical properties SrMg2 (, P, As, Sb, Bi) Zintl compounds**Project supported by a grant from the “Research Center of Female Scientific and Medical Colleges”, the Deanship of Scientific Research, King Saud University. Yaseen M is thankful to Higher Education Commission (HEC), Pakistan for funding (Grant No. 6410/Punjab/NRPU/R&D/HEC/2016), and also this study is

The effect of replacing the anion from N to Bi down the group in the periodic table is investigated on (X=N, P, As, Sb, Bi). A full potential linearized augmented plane wave plus local orbitals method is used along with different exchange–correlation potentials to obtain the lattice constants, phonons, electronic, and optical properties of the (X =N, P, As, Sb, Bi) Zintl compounds. A good agreement is achieved and our calculations are validated by previous experimental and theoretical data. All compounds have shown stable dynamical behavior with gamma centered longitudinal response having no imaginary frequencies. Electronic band structures reveal the semiconducting nature of the compounds. The Pnictogen (X)-p state contributed mainly in the valence band and the Sr-d state forms the conduction of the compounds. Relative charge transfer and low overlapping of the atomic densities indicates the preferable ionic bonding character of these materials. In the optical properties, real and imaginary parts of dielectric function, complex refractive index, birefringence, reflectivity, and optical conductivity are calculated. These compounds can be utilized in the optical and optoelectronic devices.

Electronic and optical properties of graphene-like InAs: An ab initio study

The present work initially investigates structural, optical, and electronic properties of graphene-like InAs by using the full potential linear augmented plane wave method in the framework of density functional theory and is then compared with the bulk Indium Arsenide in the wurtzite phase. The lattice parameters are optimized with GGA-PBE and LDA approximations for both 2D- and 3D-InAs. In order to study the electronic properties of graphene-like InAs and bulk InAs in the wurtzite phase, the band gap is calculated by GGA-PBG and GGA-EV approximations. Moreover, optical parameters of graphene-like InAs and bulk InAs such as the real and imaginary parts of dielectric function, electron energy loss function, refractivity, extinction and absorption coefficients, and optical conductivity are investigated. Plasmonic frequencies of 2D- and 3D-InAs are also calculated by using maximum electron energy loss function and the roots of the real part of the dielectric function.

Electronic structure and optical properties of Al0.25Ga0.75N with point defects and Mg-defect complexes

To study the influence of point defects on optoelectronic properties of Al0.25Ga0.75N, models of intrinsic and Mg doped Al0.25Ga0.75N crystals with various defects were built. Based on first-principles calculations, formation energies, electronic structure, and optical properties were calculated. Results show that N vacancy (VN) owns the smallest formation energy in p-type condition, and it always acts as a donor. Ga vacancy (VGa) always acts as an acceptor and owns the smallest formation energy in n-type condition. Interstitial N defect (Ni), Ga antisite defect (GaN), and N antisite defect (NGa) act as donors in p-type condition while they act as acceptors in n-type condition. N-type defects VN and Gai form complexes with p-type Mg impurity, and the complexes exist stably in Al0.25Ga0.75N crystal with high binding energy. The Fermi level of crystal with MgGa–VN moves into band gap and that with MgGa–Gai enters into conduction band, showing that their p-type property is damaged. Compared with intrinsic crystal without defects, the peaks of imaginary part of dielectric function for the defective crystals all shift to lower energy region. Besides, the metal reflective regions and the absorption edges of crystals with defects shift to lower energy region significantly, showing that the band gaps of defective crystals are smaller.

CI24‐Si: a Semiconducting Silicon Phase with an All‐sp3 Bonding Network

AbstractA silicon allotrope which consists of 24 atoms in a body centered cubic cell and displays an symmetry (termed as cI24‐Si) with a mass density of 2.38 g/cm3, is theoretically investigated. This silicon phase has an all‐sp3 network with hexagons. Phonon dispersion confirms its dynamical stability and elastic constant implies it is mechanically stable. The analysis of electronic band structure performing by HSE06 functional shows that cI24‐Si is an indirect semiconductor with a small band gap of 0.83 eV. Additionally, its direct band gap is only 0.02 eV larger than the indirect band gap, indicating that cI24‐Si possesses a quasi‐direct band gap. The calculations of imaginary part of dielectric function and optical absorption for cI24‐Si show that it has better optical properties than diamond‐like Si−I phase as it can capture more sunlight from visible to ultraviolet range. To provide more characterizations for future experimental observations, X‐ray diffraction patterns and Raman spectra are also theoretically simulated. Due to its small band gap, cI24‐Si may possess potential electronic, optical and photovoltaic applications.

First-principles study on the optical properties of Fe-doped GaN

Using hybrid density functional theory, we investigate the structural, electronic and optical properties of pristine GaN and Fe-doped GaN with a Fe concentration of 12.5%. Specifically, we first analyze the crystal lattice constant, band structure, and density of states, respectively. Then we predict the dielectric function, absorption coefficient, refractive index, reflectivity, energy-loss spectrum and extinction coefficient. Finally, we analyze the influences of the doping of Fe element on the photoelectric property of Fe doped systems. The calculated lattice constants for perfect GaN are a=b=3.19 Å, c=5.18 Å, which are in good agreement with the experimental values. Furthermore, we find that the doping of Fe element has little effect on the structural properties of GaN. The Band gap of pristine GaN is predicted to be 3.41 eV, very close to the experimental value of 3.39 eV. The band gap of Fe doped GaN (12.5%) significantly decreases to 3.06 eV. By comparing the densities of states of the systems with and without Fe doping, it is found that Fe-3 d state is mainly responsible for the decrease of band gap. The calculated static dielectric constant of perfect GaN is 5.74, and it increases to 6.20 after incorporating the Fe element. The results about the imaginary part of dielectric function show that two equal-strength perfect GaN peaks are observed to be at 6.81 eV and 10.85 eV. The first peak is closely related to the direction transition from the valence band top to the conduction band bottom. Furthermore, it is also observed that a peak is located at 4.04 eV in the low energy, which can be understood as resulting from the electron transition inside the valence band. The optical absorption edge of the intrinsic GaN is 3.25 eV, corresponding to the transition energy. The reason why this energy is smaller than the bandgap is because the electronic band gap equals the sum of optical bandgap and exciton energy. However, the maximum absorption coefficients of these two systems both occur at 13.80 eV in energy. The refractive index for intrinsic system is 2.39, and it increases to 2.48 after doping the Fe element. It is found from the energy-loss spectrum that the maximum energy-loss is at 20.02 eV for a perfect system, while it is at 18.96 eV for a doped system. Additionally, we obtain the reliable reflectivity and excitation coefficient. In conclusion, our calculated results provide a well theoretical basis for the theoretical research on the co-doping of Fe element and other elements. The analyses on the Fe-doped GaN high-voltage photoconductive switch materials and devices also provide a powerful theoretical basis and experimental support in the future research.

Photoelectric properties of Ag and Cr co-doped LiZnP new diluted magnetic semiconductors

Spintronic devices utilize the electron charge and spin degree of freedom to achieve novel quantum functionalities. Diluted magnetic semiconductors (DMS) constitute an important category of spintronic materials that have the potential to be successfully incorporated into the existing semiconductor industry. The prototypical DMS (Ga,Mn) As, discovered in the 1990s, accomplishes spin and charge doping simultaneously through the heterovalent substitution of the magnetic ion Mn2+ for Ga3+. Two challenges have presented themselves in this material. First, the heterovalent nature of this integrated spin/charge doping results in severely limited chemical solubility in (Ga,Mn) As, restricting specimen fabrication to metastable thin films by molecular beam epitaxy; second, the simultaneous spin and charge doping precludes the possibility of individually tuning the spin and charge degree of freedom. A new type of ferromagnetic DMS based on I-Ⅱ-V group can overcome both of these challenges. Li(Zn,Mn) As utilizes excess Li concentration to introduce hole carriers, while independently making the isovalent substitution of Mn2+ for Zn2+ in order to achieve local spin doping. With no heterovalent substitution to restrict chemical solubility, bulk samples of Li(Zn,Mn) As are successfully fabricated. However, one drawback of Li(Zn,Mn) As is its use of the toxic element As. The isostructural direct-gap semiconductor LiZnP also undergoes a ferromagnetic transition upon Mn doping, and its bulk magnetic properties are very similar to those of LiZnAs. In this paper, the geometric structure of pure LiZnP, Ag doped, Cr doped, and Ag-Cr co-doped LiZnP new diluted magnetic semiconductor are optimized by using the first-principles plane wave ultra-soft pseudo-potential technology based on the density function theory. Then we calculate the electronic structure, magnetism, formation energy, differential charge density, and optical properties of the doped systems. The results show that the material is a paramagnetic metal after single doping of the nonmagnetic element Ag. When magnetic element Cr is doped with LiZnP, sp-d orbital hybridization makes the peak of density of state nearly EF-split, leading the system to become metallic ferromagnetism. However, Ag-Cr co-doped LiZnP changes into half-metallic ferromagnetism, which is completely different from the single doping system. The band gap decreases slightly, and the electrical conductivity is enhanced. Meanwhile, the formation energy of the system becomes lower, the bond between atoms strengthens, and the stability of the unit cell becomes stronger. A comparison of the optical properties indicate that the imaginary part of dielectric function and the optical absorption spectrum both present new peaks in low energy region in the doped systems. Ag-Cr co-doped LiZnP has the highest dielectric peak. Meanwhile, the complex refractive index function changes obviously in a low energy region, and the absorption edge extends to the low energy direction. The system enhances the absorption of low-frequency electromagnetic waves.

First-principles study of electronic structures and optical properties of Mn and Cu doped potassium hexatitanate (K2Ti6O13)

Potassium hexatitanate (K2Ti6O13) is a kind of wide band-gap semiconductor material with potential applications in photocatalysis. Unfortunately, it only responds to the short wavelengths of ultraviolet light, which seriously limits the utilization efficiency of solar energy. To extend its response to visible light, a promising strategy is to partly substitute some other transition metals for the Ti element. In this work, the electronic structures and optical properties of Mn-and Cu-doped K2Ti6O13 are systematically investigated by the first-principles calculations with the aid of the CASTEP module in the Materials Studio software package. The PW91 exchange-correlation functional is used with a plane wave basis set up to a 340 eV cutoff. The computational results show that the Mn-and Cu-doped K2Ti6O13 have impurity bands mainly stemming from the mix of Mn or Cu 3d states with Ti 3d states and O 2p states. Compared with the band gap of pristine K2Ti6O13 (2.834 eV), the band gap of Mn-doped one becomes narrow (2.724 eV), and its impurity energy level in the middle of the band gap can be used as a bridge for electronic transitions to facilitate the absorption of visible light. Although the band gap of Cu-doped K2Ti6O13 slightly increases (2.873 eV), it could be greatly narrowed (1.886 eV) when taking into consideration the impurity energy levels closely connected to the valence band. In addition, the impurity energy levels may form a shallow acceptor and suppress the carrier recombination in the Cu-doped K2Ti6O13. As usual, the calculated imaginary part of dielectric function as a function of photon energy shows that the ε2(ω) value is nearly zero for pure K2Ti6O13 when the photon energy is less than 3.5 eV, whereas there are finite values and also some peaks for the Mn-and Cu-doped ones. These peaks may originate from the impurity energy levels, whose occurrence makes the electron excitation occur readily by low photon energy. Thus, the absorption edges in the doped ones can red-shift to the visible-light region with enhancing absorption intensity. Finally, the simulated absorption spectra of the pristine and doped K2Ti6O13 are consistent with their electronic structures, which further confirms the above analysis. All the results show that the Cu-doped K2Ti6O13 exhibits higher visible-light photocatalytic efficiency than the Mn-doped one. The current work demonstrates that the absorption of visible light can be realized by the Mn or Cu doped potassium hexatitanate, with the effect of the latter being better than that of the former. The obtained conclusions are of great significance for understanding and further developing the potential applications of K2Ti6O13 in the field of photocatalysis.

Electronic, electrical and optical properties of Ag doped CuO through modified Becke-Johnson exchange potential

This study examined the influence of the Ag doping concentration on the structural, electrical and optical properties of copper oxide (CuO), using the density functional theory DFT with Tran-Blaha modified Becke-Johnson (mBJ). Based on the optimized structural parameters, the structural properties, the band gaps, density of states (DOS), the profiles of the optical spectra and optical properties, including the real and imaginary parts of dielectric function, absorption coefficient, reflectivity and refractive index are obtained and showed a good agreement with experimental results. Beside this, our results indicate that CuO is an antiferromagnetic semiconductor material with an indirect gap about 1.99 eV. This increasing with decreasing Silver concentration. Furthermore, the absorption spectra display excellent physical behavior in the range of visible light which it is in good with agreement with many experimental data. In fact, this confirms the physical characteristics that can present CuO to be used as suitable absorbent material in solar cells.

Electronic and Optical Properties of GaAs Bilayer

In the present work, we have systematically studied structural, electronic and optical properties of buckled GaAs bilayer with and without spin‐orbit coupling by density functional theory. Buckled GaAs bilayer have direct band gap of 0.70 eV at high symmetric Г‐point which is low as compare to GaAs monolayer. Optical properties such as real and imaginary part of dielectric functions, refractive index, extinction coefficient, absorption spectrum and reflectivity are well studied using density function theory. The calculated optical properties show that the buckled GaAs bilayer can be beneficial for optoelectronic and light emitting devices.

Hydrogen storage in lithium hydride: A theoretical approach

First principles calculations have been carried out to analyze structural stability of lithium hydride (LiH) in NaCl phase using the full potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT). Calculations have been extended to physiosorbed H-atom compounds LiH·H2, LiH·3H2 and LiH·4H2. The obtained results are discussed in the paper. The results for LiH are in excellent agreement with earlier reported data. The obtained direct energy band gap of LiH is 3.0 eV which is in excellent agreement with earlier reported theoretical band gap. The electronic band structure plots of the hydrogen adsorbed compounds show metallic behavior. The elastic constants, anisotropy factor, shear modulus, Young's modulus, Poisson's ratio and cohesive energies of all the compounds are calculated. Calculation of the optical spectra such as the real and imaginary parts of dielectric function, optical reflectivity, absorption coefficient, optical conductivity, refractive index, extinction coefficient and electron energy loss are performed for the energy range 0–15 eV. The obtained results for LiH·H2, LiH·3H2 and LiH·4H2, are reported for the first time. This study has been made in search of materials for hydrogen storage. It is concluded that LiH is a promising material for hydrogen storage.