Ground-state Total Energy Research Articles

Investigation of spin polarized semiconductor Cs2XMoBr6 (X = Li, Na) compounds for spintronic and optoelectronic applications

This study has applied the density functional theory (DFT) to calculate the structural, magnetoelectronic, optical, and thermoelectric characteristics of Cs2XMoBr6 (X = Li, Na). The magnetic stability of studied compounds is examined by minimizing their total ground state energies. Also, both compounds exhibit cubic stability by tolerance factor as well as negative enthalpy of formation. The analysis of spin-dependent electronic properties reveals the semiconductor nature of mentioned materials in both spin-up/dn versions. The computed Eg of 0.90/1.99 eV in spin-up/dn sections for Cs2NaMoBr6 while Cs2LiMoBr6 reveals Eg of 1.99/1.21 eV in spin-up/dn version. The optical properties show that incident light is optimally absorbed in visible to ultraviolet areas, indicating their potential use in UV-based photo sensors and other photovoltaic gadgets. The Mo-atom primarily participate to the total magnetic moment (μB(Tot)) for Cs2XMoBr6. Further, the material's high figure of merit (ZT) >0.7 within the 300 - 800 K temperature range for Cs2XMoBr6 indicate its high efficiency in thermoelectric (TE) applications. Semiconducting electronic bands with highly asymmetric spin polarization as well as greater TE efficiency, Cs2XMoBr6 materials are appropriate for uses in spintronics and energy harvesting.

How do spin-scaled double hybrids designed for excitation energies perform for noncovalent excited-state interactions? An investigation on aromatic excimer models.

Time-dependent double hybrids with spin-component or spin-opposite scaling to their second-order perturbative correlation correction have demonstrated competitive robustness in the computation of electronic excitation energies. Some of the most robust are those recently published by our group (M. Casanova-Páez, L. Goerigk, J. Chem. Theory Comput. 2021, 20, 5165). So far, the implementation of these functionals has not allowed correctly calculating their ground-state total energies. Herein, we define their correct spin-scaled ground-state energy expressions which enables us to test our methods on the noncovalent excited-state interaction energies of four aromatic excimers. A range of 22 double hybrids with and without spin scaling are compared to the reasonably accurate wavefunction reference from our previous work (A. C. Hancock, L. Goerigk, RSC Adv. 2023, 13, 35964). The impact of spin scaling is highly dependent on the underlying functional expression, however, the smallest overall errors belong to spin-scaled functionals with range separation: SCS- and SOS- PBEPP86, and SCS-RSX-QIDH. We additionally determine parameters for DFT-D3(BJ)/D4 ground-state dispersion corrections of these functionals, which reduce errors in most cases. We highlight the necessity of dispersion corrections for even the most robust TD-DFT methods but also point out that ground-state based corrections are insufficient to completely capture dispersion effects for excited-state interaction energies.

Exploring the multifaceted properties: electronic, magnetic, Curie temperature, elastic, thermal, and thermoelectric characteristics of gadolinium-filled PtSb3 skutterudite.

The investigation of binary and filled skutterudite structures, particularly PtSb3 and GdPt4Sb12, has gained significant attention, becoming a focal point in scientific research. This comprehensive report delves into the intrinsic characteristics of these structures using Density Functional Theory (DFT). Initially, we assess the structural stability of PtSb3 and GdPt4Sb12 by examining their total ground state energy and cohesive energy, employing the Brich Murnaghan equation of state to determine stability in various configurations. Further insights are gained by exploring second-order elastic constants (SOEC's) to extend our understanding of structural stability. The electronic structures are then meticulously defined through a quantum mechanical treatment, employing a combination of two distinct spin-polarized approximation schemes: Perdew-Burke-Ernzerhof Generalised Gradient Approximation (PBE-GGA) and Tran-Blaha modified Becke-Johnson (TB-mBJ). The resulting band structures reveal a symmetry in electronic behavior, showcasing spin-magnetic moments of 3 μB and 7.58 μB per formula unit, with the primary contributions emanating from the Pt 3d and Pt4+ 3d-transition elements. To gauge thermal stability, we evaluate the phonon-dependent Grüneisen parameter (γ) across specific temperature ranges. The study extends to exploring transport properties as a function of chemical potential (μ - EF) at various temperatures. The findings suggest that these designed materials hold substantial potential for diverse applications, particularly in conventional spin-based and thermoelectric technologies. The comprehensive insights obtained through this investigation pave the way for a deeper understanding and broader implications in various technological domains.

Understanding the computational insights of spin-polarised density functional theory into the newly half-metallic f electron-based actinide perovskites SrMO3 (M = Pa, Np, Cm, Bk)

Here, we investigated the structural, mechanical, electronic, magnetic, thermodynamic and thermoelectric properties of Strontium based simple perovskites SrMO3 (M = Pa, Np, Cm, Bk) by using density functional theory. First and foremost, the ground state stability of these perovskites was initially evaluated by optimizing their total ground state energies in distinct ferromagnetic and non-magnetic configurations. The structural stability in terms of their ground state energies defines that these alloys stabilize in ferromagnetic rather than competing non-magnetic phase. From the understandings of mechanical parameters these alloys are characterized to be ductile in nature. After that, two approximation schemes namely Generalized Gradient approximation and Tran-Blaha modified Becke-Johnson potential have been used to find their intimate electronic structures which displays the half-metallic nature of these alloys. Further, we have verified temperature and pressure effect on these alloys. Finally, the transport properties have been evaluated within the selected temperature range of 150–900 K. In view of this, the different transport parameters along with half-metallic nature advocate their possible applications in thermoelectric and spintronics devices.

DFT modeling techniques to understand the potential applicability of novel double perovskite semiconductor Ba2LuNbO6 for sustainable thermoelectrics and optoelectronic perspectives

Searching for novel functional materials represents an important direction in the research and development of renewable energy. Herein, experimentally synthesised Ba2LuNbO6 (BLNO) host double perovskite has been theoretically computed by first principles techniques to understand its several physical properties like electronic-structure, mechanical behaviour, transport along with optical and thermal properties upon the basis of full potential linearized augmented plane wave (FP-LAPW) followed by density functional theory (DFT). First and foremost, the attempt was significant made to relax the molecular crystal structure of BLNO at an experimental lattice constant to evaluate its total ground state and cohesive energy (Ecoh) for descripting its required structural stability. After that, we have overseen its mechanical stability from the computation of second order elastic constants (SOEC's). Later on, the electronic properties of this alloy have been executed within the two potential schemes like Perdew-Burke Generalized gradient approximation (PBE-GGA) and Tran-Blaha modified Becke-Johnson (TB-mBJ) which alternatively certifies the retention of the semiconducting nature respectively. Besides this, the essential use of semi-classical Boltzmann theory within the sophisticated scheme of BoltzTraP has been inducted to explore its transport coefficients. And finally, the optical has been summarised to see the applicability of this particular alloy towards optoelectronic application purposes. Therefore, the overall tendency of this particular alloy can favor their potential multiple applications in sustainable thermoelectrics, optoelectronic features etc.

Structural, Electronic & Magnetic Properties of Pristine and Defected ZnO Monolayer: First-Principles Study

Electronic and magnetic properties of materials are appealing properties and have budding applications in the devices. In this work, we have investigated the structural, electronic and magnetic properties of pristine Zinc-Oxide (ZnO) and Oxygen-defected Zinc-Oxide (ZnO_O) materials by spin-polarized density functional theory (DFT) method. Structural properties are studied by calculating their total ground state energy, and found that both are stable 2D materials. It is also found that ZnO have higher stability than of ZnO_O material. Electronic properties of considered materials are examined by analyzing of their band structure, density of states (DOS) calculations and found that ZnO is a direct band gap, n-type semiconductor material in its pristine form and an indirect band gap, p-type semiconductor material in its Oxygen-defected form (ZnO_O). Magnetic properties of pristine and defected ZnO are investigated by analyzing their density of states (DOS) and partial density of states (PDOS) calculations, they revealed that ZnO and ZnO_O have non-magnetic properties.

Can We Observe Nonperturbative Vacuum Shifts in Cavity QED?

We address the fundamental question of whether or not it is possible to achieve conditions under which the coupling of a single dipole to a strongly confined electromagnetic vacuum can result in nonperturbative corrections to the dipole's ground state. To do so we consider two simplified, but otherwise rather generic cavity QED setups, which allow us to derive analytic expressions for the total ground-state energy and to distinguish explicitly between purely electrostatic and genuine vacuum-induced contributions. Importantly, this derivation takes the full electromagnetic spectrum into account while avoiding any ambiguities arising from an adhoc mode truncation. Our findings show that while the effect of confinement perse is not enough to result in substantial vacuum-induced corrections, the presence of high-impedance modes, such as plasmons or engineered LC resonances, can drastically increase these effects. Therefore, we conclude that with appropriately designed experiments it is at least in principle possible to access a regime where light-matter interactions become nonperturbative.

Investigating the role of carbon doping on the structural and energetic properties of small aluminum clusters using quantum Monte Carlo.

In this study, we investigate the energetics of small aluminum clusters doped with a carbon atom using several computational methods, including diffusion quantum Monte Carlo, Hartree-Fock (HF), and density functional theory. We calculate the lowest energy structure, total ground-state energy, electron population distribution, binding energy, and dissociation energy as a function of the cluster size of the carbon-doped aluminum clusters compared with the undoped ones. The obtained results show that carbon doping enhances the stability of the clusters mainly due to the electrostatic and exchange interactions from the HF contribution gain. The calculations also indicate that the dissociation energy required to remove the doped carbon atom is much larger than that required to remove an aluminum atom from the doped clusters. In general, our results are consistent with available theoretical and experimental data.

First-principles calculations to investigate structural, electronic, phonon, magnetic and thermal properties of stable halide perovskite semiconductors Cs2GeMnI6 and Cs2GeNiI6

Since, the systematic and extensive study on halide double perovskite’s (HDP’s) have triggered a considerable interest, thus became a new thrust to the scientific research. In this organised report, we present a new promising halide double perovskite structures Cs2GeMnI6 and Cs2GeNiI6 to understand, more in-depth their intrinsic characteristics by means of Density Functional Theory (DFT). Initially, we reported the structural stability of both these crystal structures by evaluating their total ground state energy in stable configuration and cohesive energy at the behest of Brich Murnaghan equation of state. Afterwards, the structural stability is moreover extended to see their corresponding tolerance factor (τ) values and second order elastic constants (SOEC’s). Subsequently, the density functional perturbation theory (DFPT) has been inducted to predict the dynamical context of these ordered systems. Later on, the quantum mechanical treatment of defining their electronic structures by the calibration of mix of two distinct spin-polarised approximation schemes like Perdew-Burke-Ernzerhof Generalised gradient approximation (PBE-GGA) followed by Tran-Blaha modified Becke-Johnson (TB-mBJ). Meanwhile, the unsymmetrical behaviour of electronic structures from their resulting band structures demonstrates the occurrence of spin-magnetic moment of 5 µB and 2 µB/formula unit respectively having the maximum contribution solely coming from the Mn+2 and Ni2+ 3d-transition elements. The evaluation of phonon dependent Grüneisen parameter (γ) defines the possible thermal stability against specific temperature regimes. And finally transport properties as a function of chemical potential (µ-EF) at distinct temperatures has been keenly explored. Therefore, the overall tendency of these designed materials can be envisaged to descript vast implications in various extending applications for conventional spin-based and thermoelectric technologies.

Enhanced photocatalysis activity of doped magnetic semiconductor (Rh/Ir):CdS by improving charge-carrier transfer mechanism

Photocatalytic splitting of water for the production of hydrogen is one of the emerging research routes in recent years. In this paper, we have performed a spin-polarized calculation to explore the effect of doping of noble metals on structural, electronic, optical, and efficiency of wurtzite Cadmium sulfide (CdS) as photo-catalyst employing electronic full potential linearized augmented plane-wave (FP-LAPW) method. The structural properties are studied with PBE-sol, whereas total ground state energies for band gap, the density of states and optical absorption are calculated by using modified Becke-Johnson generalized gradient approximation (mBJ-GGA). The calculations show that the Rh and Ir as mono-doped in Cd sites are stable candidates for photo-catalytic splitting of water. For the requirements of photocatalytic splitting of water to produce hydrogen, we have calculated the edge potentials of conduction and valence band. Rh and Ir as mono-doping in Cd sites increase the difference of electron-hole ratios that lead to small recombination rate of electron-hole photo-generated pairs. For optical properties, the incorporation of Rh and Ir in CdS lattice, the optical absorption in visible spectra increases with increasing concentration and it reflects the efficient for photo-catalytic activity.

Theoretical exploration of inherent electronic, structural, mechanical, thermoelectric, and thermophysical response of KRu4Z12 (Z = As12, Sb12) filled skutterudite materials.

Using the density functional theory methodology, we have thoroughly examined KRu4As12 and KRu4Sb12 skutterudites, including their structural, electronic, mechanical, transport, and thermodynamic properties. First and foremost, using the Birch-Murnaghan equation of state, the structural stability has been calculated in terms of their total ground state and cohesive energies. With the use of the approximation approaches GGA and GGA + mBJ, the electrical structure and density of the states reveal their metallic nature. This demonstration predicts the dominant ferromagnetic spin configuration of materials by considering their electronic behavior and magnetic interactions. The ductile behavior of these alloys is also addressed by their mechanical qualities, which indicate how they might be used in engineering and industrial settings. Moreover, the semi-classical Boltzmann transport theory has been employed to examine the Seebeck coefficient as well as the electric and thermal conductivities. The general tendency of these compounds demonstrates their various potential uses as electrode materials. The quasi-harmonic Debye approximation is a method used to analyze the stability of a system under high pressures and accounts for the temperature dependency of thermodynamics. It combines the quasi-harmonic approximation, which considers the anharmonicity of vibrations, with the Debye model, which describes the vibrational modes of a solid. This approach allows for a more accurate representation of the system's behavior at different temperatures and pressures. By implementing this approximation, researchers can gain insights into the stability and thermodynamic properties of materials under extreme conditions.

Electronic-Structure Properties from Atom-Centered Predictions of the Electron Density.

The electron density of a molecule or material has recently received major attention as a target quantity of machine-learning models. A natural choice to construct a model that yields transferable and linear-scaling predictions is to represent the scalar field using a multicentered atomic basis analogous to that routinely used in density fitting approximations. However, the nonorthogonality of the basis poses challenges for the learning exercise, as it requires accounting for all the atomic density components at once. We devise a gradient-based approach to directly minimize the loss function of the regression problem in an optimized and highly sparse feature space. In so doing, we overcome the limitations associated with adopting an atom-centered model to learn the electron density over arbitrarily complex data sets, obtaining very accurate predictions using a comparatively small training set. The enhanced framework is tested on 32-molecule periodic cells of liquid water, presenting enough complexity to require an optimal balance between accuracy and computational efficiency. We show that starting from the predicted density a single Kohn-Sham diagonalization step can be performed to access total energy components that carry an error of just 0.1 meV/atom with respect to the reference density functional calculations. Finally, we test our method on the highly heterogeneous QM9 benchmark data set, showing that a small fraction of the training data is enough to derive ground-state total energies within chemical accuracy.

DFT analogue of prospecting the spin-polarised properties of layered perovskites Ba2ErNbO6 and Ba2TmNbO6 influenced by electronic structure

Since the unexpected accelerated discovery of half-metallic perovskites is continuously on the rise both from basic sciences and application-oriented sides. Herein, for the first time in this carried research work, we significantly delivered a detailed analysis on one of experimentally synthesized perovskite structure Ba2ErNbO6 and in related to Ba2TmNbO6 within the realm of unified density functional theory. Initially, the structural stability of two molecular perovskite structures were critically established interms of their total ground state and cohesive energies by the expendition of Brich Murnaghan equation of state. Also, the tolerance factor (τ) oversees the cubic structural stability without possessing any geometrical strains. More likely, the density functional perturbation theory (DFPT) has been calibrated to perceive the dynamical context of these layered structures. Also, from the understandings of second order elastic and mechanical parameters adresses their suitable ductile characteristics. The quantum mechanical refinement of their intrinsic electronic structures were systematically tuned by the exploitation of Generalised gradient approximation (GGA), on-site Hubbard scheme (GGA + U) selected to the strongly correlated electrons of particular angular momentum and modified Becke-Johnson (mBJ) potential. Moreover, the two-dimensional representation of asymmetric density of states (DOS) pinned around the Fermi-level (EF) and the interpretation linked to their corresponding spin-polarised band structures signatures the well-known half-metallic nature. Subsequently, the transport properties especially the value of figure of merit (ZT) equals to unity (1) along the selected chemical potential range at different temperatures. The summed-up properties and the overall tendency triggers the possibility of these materials to register their extending applications in spintronics, thermoelectrics, nanoengineering, and radioisotope generator perspectives.

Large Gap Topological Insulating Phase and Anisotropic Rashba and Chiral Spin Textures in Monolayer Zintl A2MX2

A family of two-dimensional (2D) materials, particularly the complex-structured Zintl phase compounds, has attracted tremendous research attention because of tunable material properties and exceptional applications. Utilizing first-principles computations under the hybrid functional approach, we performed a systematic study on A2MX2 (A = Ca, Sr, or Yb; M = Zn or Cd; X = P, As, Sb, or Bi). Among the three surface terminations considered, the metal element XM-termination (T2) was found to be the most stable structural phase with the lowest total ground state energies. Thermodynamic stability was further confirmed through phonon dispersion and formation energy calculations. Surprisingly, the T2 monolayer Sr2CdBi2 was found to host the topological insulating phase with a sizable bandgap of 556 meV, as well as a Z2 topological invariance of 1. The corresponding topologically protected edge states link the conduction and valence bands. Moreover, the topological phase is driven by the spin–orbit coupling, which causes the inverted bands at Γ point close to the Fermi level concerning the Cd-s + Bi2-s and Bi2-px + py orbitals. Moreover, Rashba and chiral spin-splittings were also observed. The computed Rashba strengths along Γ-M (αRΓ-M) are 1.970, 0.676, and 0.669 eV·Å, whereas the computed values along Γ-K (αRΓ-K) are 1.701, 0.731, and 0.646 eV·Å, for Ca2ZnAs2, Sr2CdBi2, and Yb2ZnAs2, respectively. Our study provides fundamental knowledge to further experimental investigations and synthesis, which may lead to electronic applications of A2MX2 compounds in quantum computing or spintronics.

Investigating the Electronic and Optical Characteristics of New Nanocomposites for Flexible Optoelectronics Nanodevices

This work aims to design of PEO/CuO new structures and investigating optical, and electronic characteristics to use in various electronic and optoelectronics devices like diodes, transistors, photovoltaic cell, electronic gates, sensors and other electronics devices. Using the B3LYP-DFT with a suitable 6-31G basis set for pure PEO and SDD basis set for nanocomposite, a good optimization structure for the predicted nanocomposites was obtained. Geometrical values that have been calculated. The results indicated that the studied nanocomposite need small energy to become cationdue to ionization potential is decrease with addition nanoparticle to the pure PEO, but the electronic affinity is an increase with addition nanoparticles to the pure PEO. When compared to other nanocomposite, the total ground state energy of PEO has the highest value of total energy, but ET dropped with the addition of nanoparticles to pure PEO. With the addition of nanoparticles to pure PEO, the hardness decreases, making nanocomposite softer, lowering a species' barrier to losing electrons. The studied nonocomposite direct electronic transition from the valence to conduction band with wave length falls within the solar spectrum range. The results revealed that the (PEO-CuO) nanocomposite has a wide range of applications in the fields of electronics and photo-electronics.

Focusing on the Structural, Electronic, Optic and Elastic Behaviours of RhBiSe Compound by Ab-initio Calculations

Some physical features such as structural, electronic, optic and elastic of RhBiSe compound were investigated theoretically by Density Functional Theory within Generalized Gradient Approximation. The lattice parameter, total ground state energy, bond types and lengths were calculated in the structural features frame. Focusing on the electronic properties has shown that RhBiSe is a semiconductor with an indirect band gap. The density of states and partial density of states were also demonstrated. Fundamental optic features obtained and it is noticed that RhBiSe is very convenient for the optical application areas such as optoelectronic devices. It was also exhibited that RhBiSe is a fragile material. The calculations on elastic features also revealed that RhBiSe is a mechanically stable, elastically anisotropic material with a high thermoelectric conductivity property.

Performance of a one-parameter correlation factor for transcorrelation: Study on a series of second row atomic and molecular systems.

In this work, we investigate the performance of a recently proposed transcorrelated (TC) approach based on a single-parameter correlation factor [E. Giner, J. Chem. Phys. 154, 084119 (2021)] for systems involving more than two electrons. The benefit of such an approach relies on its simplicity as efficient numerical-analytical schemes can be set up to compute the two- and three-body integrals occurring in the effective TC Hamiltonian. To obtain accurate ground state energies within a given basis set, the present TC scheme is coupled to the recently proposed TC-full configuration interaction quantum Monte Carlo method [Cohen et al., J. Chem. Phys. 151, 061101 (2019)]. We report ground state total energies on the Li-Ne series, together with their first cations, computed with increasingly large basis sets and compare to more elaborate correlation factors involving electron-electron-nucleus coordinates. Numerical results on the Li-Ne ionization potentials show that the use of the single-parameter correlation factor brings on average only a slightly lower accuracy (1.2 mH) in a triple-zeta quality basis set with respect to a more sophisticated correlation factor. However, already using a quadruple-zeta quality basis set yields results within chemical accuracy to complete basis set limit results when using this novel single-parameter correlation factor. Calculations on the H2O, CH2, and FH molecules show that a similar precision can be obtained within a triple-zeta quality basis set for the atomization energies of molecular systems.

Ab initio diffusion quantum Monte Carlo study of the structural and electronic properties of small Lithium-Chloride LinCl (0,1+) (n = 1–7) clusters

Superalkali metal clusters as the potential building blocks of nanostructured materials have excellent nonlinear optical properties. In the present study, the structural and electronic properties of small LinCl (0,1+) (n = 1–7) clusters are investigated by the diffusion Monte Carlo method for the first time. We calculate the total ground state energy, ionization potential, binding energy, dissociation energy, and second difference in energy. We also analyze the contribution of electron correlation effects to the electron properties of the clusters. The DMC results of ionization potentials are more consistent with the experimental values. In addition, there is an odd–even alternation phenomenon that Li3Cl, Li5Cl, and Li7Cl are more stable, while Li2Cl+, Li4Cl+, and Li6Cl+ are more stable. The successful application of the quantum Monte Carlo (QMC) method on the small LinCl (0,1+) (n = 1–7) clusters implies that QMC may serve as a feasible tool to investigate the electronic properties of other superalkli metal clusters.

Reformulation of thermally assisted-occupation density functional theory in the Kohn–Sham framework

We reformulate the thermally assisted-occupation density functional theory (TAO-DFT) into the Kohn-Sham single-determinant framework and construct two new post-self-consistent field (post-SCF) static correlation correction schemes, named rTAO and rTAO-1. In contrast to the original TAO-DFT with the density in an ensemble form, in which each orbital density is weighted with a fractional occupation number, the ground-state density is given by a single-determinant wavefunction, a regular Kohn-Sham (KS) density, and total ground state energy is expressed in the normal KS form with a static correlation energy formulated in terms of the KS orbitals. In post-SCF calculations with rTAO functionals, an efficient energy scanning to quantitatively determine θ is also proposed. The rTAOs provide a promising method to simulate systems with strong static correlation as original TAO, but simpler and more efficient. We show that both rTAO and rTAO-1 is capable of reproducing most results from TAO-DFT without the additional functional Eθ used in TAO-DFT. Furthermore, our numerical results support that, without the functional Eθ, both rTAO and rTAO-1 can capture correct static correlation profiles in various systems.

Prediction of topological Dirac semimetal in Ca-based Zintl layered compounds CaM2X2 (M\u2009=\u2009Zn or Cd; X\u2009=\u2009N, P, As, Sb, or Bi)

Topological Dirac materials are attracting a lot of attention because they offer exotic physical phenomena. An exhaustive search coupled with first-principles calculations was implemented to investigate 10 Zintl compounds with a chemical formula of CaM2X2 (M = Zn or Cd, X = N, P, As, Sb, or Bi) under three crystal structures: CaAl2Si2-, ThCr2Si2-, and BaCu2S2-type crystal phases. All of the materials were found to energetically prefer the CaAl2Si2-type structure based on total ground state energy calculations. Symmetry-based indicators are used to evaluate their topological properties. Interestingly, we found that CaM2Bi2 (M = Zn or Cd) are topological crystalline insulators. Further calculations under the hybrid functional approach and analysis using k · p model reveal that they exhibit topological Dirac semimetal (TDSM) states, where the four-fold degenerate Dirac points are located along the high symmetry line in-between Г to A points. These findings are verified through Green's function surface state calculations under HSE06. Finally, phonon spectra calculations revealed that CaCd2Bi2 is thermodynamically stable. The Zintl phase of AM2X2 compounds have not been identified in any topological material databases, thus can be a new playground in the search for new topological materials.