Time-dependent Density Functional Theory Research Articles

Electronic structure of 2(5H)-thiophenone studied by UPS and soft X-ray spectroscopy

Abstract The electronic structure of 2(5H)-thiophenone in the gas phase was investigated by ultraviolet photoelectron spectroscopy (UPS) and x-ray photoemission spectroscopy (XPS) and near edge x-ray absorption fine structure (NEXAFS) spectroscopy at the C 1s, O 1s, and S 2p edges. All assignments of the experimental results are supported by both ab-initio electron propagator OVGF calculations for the valence photoemission bands and density functional theory (DFT) and relativistic time dependent DFT calculations for the core levels XPS and NEXAFS spectra. Overall good agreement between experiment and theory is observed; this is especially true for core electron excitations which has permitted an unambiguous assignment of the observed spectral features in terms of single-particle excitations to virtual molecular orbitals. The assignment of the valence band spectra based on OVGF calculations, although satisfactory, points to the importance of electron correlations effects that partially break the single particle picture of ionization.

Electrical conductivity of warm dense hydrogen from Ohm’s law and time-dependent density functional theory

Abstract Understanding the electrical conductivity of warm dense hydrogen is critical for both fundamental physics and applications in planetary science and inertial confinement fusion. We demonstrate how to calculate the electrical conductivity using the continuum form of Ohm’s law, with the current density obtained from real-time time-dependent density functional theory. This approach simulates the dynamic response of hydrogen under warm dense matter conditions, with temperatures around 30,000 K and mass densities ranging from 0.02 to 0.98 g/cm³. We systematically address finite-size errors in real-time time-dependent density functional theory, demonstrating that our calculations are both numerically feasible and reliable. Our results show good agreement with other approaches, highlighting the effectiveness of this method for modeling electronic transport properties from ambient to extreme conditions.

Hot carrier transfer from plasmon decay in Ag20at H-Si(111) surface: real-time TDDFT simulation in Wannier gauge.

Plasmon decay is believed to play an essential role in inducing hot carrier transfer at the interfaces between plasmonic nanoparticles and semiconductor surfaces. In this work, we employ real-time time-dependent density functional theory (RT-TDDFT) simulation in the Wannier gauge to gain quantum-mechanical insights into the nonlinear dynamics of the plasmon decay in the Ag20nanoparticle at a semiconductor surface. The first-principles simulations show that the plasmon decay is more than two times faster when the Ag20nanoparticle is adsorbed on a hydrogen-terminated Si(111) surface, taking place within 100 femtoseconds of the plasmon excitation. Hot carrier transfer across the interface is observed as the plasmon decay takes place, and nearly 30% of holes are generated deep in the valence band of the semiconductor surface. The use of Wannier gauge in RT-TDDFT simulation is particularly convenient for gaining quantum-mechanical insights into non-equilibrium electron dynamics in complex heterogeneous systems.

A theoretical exploration of the influence of oxygen element on photo-induced behaviours for flavonoid derivatives with Me2N substitution

The exceptional properties of flavonoid derivatives are a great inspiration for our research. In the fields of medicine and chemistry, flavonoids present the superior ability to enhance non-specific immune function and humoral immune response. Herein, our primary focus lies in the theoretical exploration of the photo-induced characteristics exhibited by the novel Me2N-substituted flavonoid (MEF) fluorophore. Considering the potential photo-induced properties associated with chalcogen atomic electronegativity in photoexcitation, using density functional theory (DFT) and time-dependent DFT (TDDFT) methods, we primarily pay attention to probing into photo-induced hydrogen bonding effects and concomitant charge reorganisation processes. Given changes in chemical geometries and the infrared (IR) vibrational shifts of three MEF derivatives (MEF-O, MEF-S and MEF-Se), we confirm that intramolecular hydrogen bonding should be strengthened by facilitating excited state intramolecular proton transfer (ESIPT) reactions. Particularly, the redistribution of charge further shows the ESIPT behaviour. By constructing potential energy curves (PECs) and identifying transitional reaction state (TS) structures, we ultimately validate the electronegativity-dependent ESIPT mechanisms of chalcogen elements in MEF derivatives. We sincerely hope that our work can accelerate future development and applications of flavonoid derivatives.

Influence of symmetry breaking on the absorption spectrum of crystal violet: from isolated cations at 5 K to room temperature solutions.

We report the resolution of a long-standing puzzle in molecular spectroscopy: the origin of the shoulder in the room temperature solution absorption spectrum of crystal violet (CV) - an archetypal cationic triphenylmethane dye. This was achieved by comparing experimental and theoretical results for CV in solution at room temperature and as an isolated cation in gas-phase at 5 K. The two lowest energy electronically excited states involved in the visible region absorption are degenerate and coupled via a Jahn-Teller (JT) mechanism involving phenyl torsions, making CV particularly sensitive to environmental perturbations. The shoulder is absent in the low-temperature isolated cation spectrum, and vibronic simulations based on time dependent density functional theory (TD-DFT) indicate negligible JT effects under these conditions. Combining vibronic simulations with molecular dynamics, demonstrates that in water and toluene solution at room temperature the shoulder arises mainly from an intermolecular, Jahn-Teller-like symmetry-breaking effect induced by the fluctuating electrostatic potential of the disordered solvent environment, rather than from molecular distortions.

Collision of cesium atoms on helium nanodroplets: Unraveling mechanisms for surface capture at experimental velocities.

The collision of cesium atoms on the surface of helium nanodroplets (HNDs) containing 1000 atoms is described by the ZPAD-mPL approach, a zero-point averaged dynamics (ZPAD) method based on a He-He pseudopotential adjusted to better reproduce the total energy of He1000. Four types of collisional patterns were identified depending on the initial projectile speed v0 and impact parameter b. At the lowest speeds (v0 ≲ 250ms-1), Cs atoms are softly captured by the HND surface, while at the highest ones (v0 ≳ 500-600ms-1), Cs atoms can travel through the droplet and move away. In between these two extreme cases, Cs atoms can be temporarily submerged in the HND before being expelled to the surface if b = 0 or cross the HND before being captured on its surface. The possibility for Cs capture at experimental velocities and droplet piercings at the highest ones contrasts with time-dependent density functional theory calculations, which predict Cs capture for velocities lower than 75ms-1, and ring-polymer molecular dynamics (RPMD) or former ZPAD-like methods, which predict soft Cs capture up to 500ms-1. ZPAD-mPL results are attributed to the liquid but non-superfluid nature of the droplet, which favors energy exchanges with the helium environment, and to low He-He binding energy and HND surface tension, which can stimulate helium ejections, especially at high projectile speeds. Despite the use of a pseudopotential to model He-He interactions, the heliophobicity of Cs atoms is maintained as demonstrated by their ability to remain localized on the HND surface or to be expelled to the HND surface after transient submersion in helium.

Photovoltaic response promoted via intramolecular charge transfer in triphenylpyridine core with small acceptors: A DFT/TD-DFT study

Currently, A−π−A configured molecules (TTP1-TTP6) were designed from the reference compound (TPPR) by modifying the terminal acceptors for photovoltaic materials. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) using the M06/6-311G(d,p) functional were employed to analyze the photonic and electronic properties of the newly designed derivatives. Various analyses; frontier molecular orbitals (FMOs), density of states (DOS), absorption spectra (λmax), transition density matrix (TDM), binding energy (Eb), hole-electron and open circuit voltage (Voc) were performed to explore the photovoltaic properties of triphenylpyridine based compounds. The structural modulation with acceptor moieties significantly tuned their HOMO and LUMO levels, resulting in reduced band gaps (2.833–3.037 eV). They also exhibited broader absorption spectra (λmax) ranging from 482.560 to 514.756 nm as compared to the reference compound (486.289 nm). Notably, TPP3 showed the good photovoltaic response as it displayed the least energy gap (2.833 eV) with lower binding energy (0.415 eV) and bathochromic shift (512.798 nm) in absorption spectra as compared to all other derivatives. Beside this, a comparative study with spiro-OMeTAD and P3HT standard hole transport materials illustrated that these materials can also be utilized as effective photovoltaic materials.

Implementation of time-dependent Hartree–Fock in real space

Abstract Time-dependent Hartree–Fock (TDHF) is one of the fundamental post-Hartree–Fock (HF) methods to describe excited states. In its Tamm-Dancoff form, equivalent to Configuration Interaction Singles, it is still widely used and particularly applicable to big molecules where more accurate methods may be unfeasibly expensive. However, it is rarely implemented in real space, mostly because of the expensive nature of the exact-exchange potential in real space. Compared to widely used Gaussian-type orbitals (GTO) basis sets, real space often offers easier implementation of equations and more systematic convergence of Rydberg states, as well as favorable scaling, effective domain parallelization, flexible boundary conditions, and ability to treat model systems. We implemented TDHF in the Octopus real-space code as a step toward linear-response hybrid time-dependent density-functional theory (TDDFT), other post-HF methods, and ensemble density-functional theory methods involving exact exchange. Calculation of HF’s non-local exact exchange is very expensive in real space. We overcome this limitation with Octopus’ implementation of Adaptively Compressed Exchange, and find the appropriate mixing scheme and starting point to complete the ground-state calculation in a practical amount of time, and thus enable TDHF. We compared our results to those from GTOs on a set of small molecules and confirmed close agreement of results, though with larger deviations than in the case of semi-local TDDFT. We find that convergence of TDHF demands a finer real-space grid than semi-local TDDFT. We also present the subtleties in benchmarking a real-space calculation against GTOs, relating to Rydberg and vacuum states.

Highly Accurate and Robust Constraint-Based Orbital-Optimized Core Excitations.

We adapt our recently developed constraint-based orbital-optimized excited-state method (COOX) for the computation of core excitations. COOX is a constrained density functional theory (cDFT) approach based on excitation amplitudes from linear-response time-dependent DFT (LR-TDDFT), and has been shown to provide accurate excitation energies and excited-state properties for valence excitations within a spin-restricted formalism. To extend COOX to core-excited states, we introduce a spin-unrestricted variant which allows us to obtain orbital-optimized core excitations with a single constraint. Using a triplet purification scheme in combination with the constrained unrestricted Hartree-Fock formalism, scalar-relativistic zero-order regular approximation corrections, and a semiempirical treatment of spin-orbit coupling, COOX is shown to produce highly accurate results for K- and L-edge excitations of second- and third-period atoms with subelectronvolt errors despite being based on LR-TDDFT, for which core excitations pose a well-known challenge. L- and M-edge excitations of heavier atoms up to uranium are also computationally feasible and numerically stable, but may require more advanced treatment of relativistic effects. Furthermore, COOX is shown to perform on par with or better than the popular ΔSCF approach while exhibiting more robust convergence, highlighting it as a promising tool for inexpensive and accurate simulations of X-ray absorption spectra.

Understanding the mechano-fluorochromic enhancement in a cyanoethylene-functionalized pyrene-based luminogen: an experimental and theoretical study

Pyrene-based luminogens have attracted wide attention due to their promising applications in organic electronics, chemical sensing, and bioimaging. In this study, a cyanoethylene-functionalized pyrene-based luminogen CNPyCH3 was designed and synthesized. Experimental results show that CNPyCH3 exhibits distinct photophysical properties in dilute solution and various solid states. The mechano-fluorochromic (MFC) property is more attractive and interesting, as a red shift with enhanced emission was observed upon mechanical stimulation. The intriguing MFC enhancement behavior was further investigated by in-depth theoretical calculations combining Monte Carlo simulations, quantum mechanics/molecular mechanics calculations, and time-dependent density functional theory. It was found that the calculated emission wavelengths for both pristine and ground CNPyCH3 are in good agreement with the experimental values, and that the ground CNPyCH3 has a greater oscillator strength. From the perspective of intermolecular interactions, the weakened π-π interactions induced by the half-switched “face-to-edge” packing modes are beneficial for achieving brighter emission upon grinding. In terms of intramolecular structures, the ground CNPyCH3 has a more planar conformation around the cyanoethylene moiety in the excited-state equilibrium geometry than the pristine CNPyCH3, resulting in the grinding-induced red-shifted emission. Our study provides a unique insight into the MFC enhancement behavior of the pyrene-based luminogens.

A “Turn‐On” Fluorescent Probe for the Visual Detection of Total Iron in Wine

ABSTRACTA turn‐on fluorescent sensor (E)‐4‐((4‐(5‐fluoro‐1H‐benzo[d]imidazol‐2‐yl)benzylidene)amino)phenol (FBAP) for the detection of Fe3+/2+ was synthesized. The fluorescence intensity of probe FBAP solution gradually increased with increased Fe3+ concentration. The low detection limit (LOD) was calculated to be 0.17 nM. The optimized structure and luminescent properties of FBAP were calculated by time‐dependent density functional theory (TD‐DFT) and Solvation Model Density (SMD). The rotation of the dihedral angle and ICT in the imine probe turned off the emission of the benzimidazole, which was restored upon cleaving the imine. Probe FBAP was successfully applied to determine whether Fe3+/2+ in wine exceeded the standard by phone and the rapid detection of Fe3+/2+ in the form of test strips was also conducted.

Relationship between antioxidant activity and ESIPT process based on flavonoid derivatives: A comprehensive analysis

Antioxidant activity, as a topic of current interest, is discussed together with the excited state intramolecular proton transfer (ESIPT) process for three flavonoid derivatives, based on density functional theory (DFT)and time-dependent DFT (TD-DFT) methods, as well as DPPH free radical scavenging assay. The potential energy curves and transition states demonstrate that the three molecules can undergo only single proton transfer in the excited state, and all of them are ultrafast ESIPT processes. The absorption spectra of all the molecules show effective protection against UV radiation with low fluorescence intensity, especially Baicalein (Bai), which demonstrates their great potential for sunscreen applications. The density of states, HOMO energy values, global and local indices reveal that the antioxidant activity of the molecules after ESIPT process is enhanced, with Bai having the highest antioxidant activity, which is significantly attributed to the number and position of phenolic hydroxyl groups. Moreover, by comparing the DPPH free radical scavenging activity under the dark and UV radiation conditions, the radical scavenging activity (RSA) value in the UV radiation is remarkably higher than that in the dark condition, in which Bai achieves RSA value of 93.4%. Overall, the antioxidant activity of all three ESIPT-based flavonoid derivatives, especially Bai, is significantly elevated in the keto* form, which reinforces the significant relationship between antioxidant activity and ESIPT process, and provides new application prospects for molecules with ESIPT properties.

A comprehensive Investigation of Donor-Acceptor anthraquinone derivatives as Versatile and efficient photosensitizers for Dye-Sensitized solar cells

A new metal-free anthraquinone donor–acceptor-π-anchor (D-A-π-A) design was developed using unsymmetrically substituted anthraquinone (ATQ) derivatives functionalized with bromine (Br), diphenylamine (DPA), indoline (Ind), BrATQBzOH, DPAATQBzOH, and IndATQBzOH. The synthesised compounds, functionalized with an anchor group (ethynylbenzoic acid), were evaluated in practical dye-sensitised solar cell, DSSC, devices with the aiming to improve electron injection efficiency. Their properties and applicability were analysed and rationalised based on their energy levels and parameters derived from the current–voltage (I-V) curve analysis in real devices. Femtosecond transient absorption measurements of the sensitiser IndATQBzOH with TiO2 revealed distinct excited state dynamics and charge transfer properties, highlighting the influence of the semiconductor interface. In addition, Density Functional Theory (DFT) and Time-Dependent DFT (TDDFT) electronic quantum calculations were performed, which revealed that the new anthraquinone-based dyes exhibit optimal coplanarity for efficient electron transfer, with their LUMO and HOMO energy levels facilitating electron injection into TiO2. In contrast to the low efficiencies found for previous anthraquinone derivatives, with maximum photocurrent efficiencies (PCE) below 0.2%, 9,10-anthraquinone derivatives were used as acceptors attached to suitable donors (DPA or Ind), and PCE above 1% were obtained.

Pioneering SubPc-Br/CdS S-scheme heterojunctions: Achieving superior photocatalytic oxidation through enhanced radical synergy and photocorrosion mitigation

For the efficient harnessing of solar energy and mitigation of environmental pollution, the development and application of semiconductor photocatalysis technology is paramount. Herein, a novel SubPc-Br/CdS supramolecular array with an S-scheme heterojunction was synthesized through the intermolecular π-stacked self-assembly of subphthalocyanine (SubPc-Br) and nanometer cadmium sulfide (CdS). This self-assembly system features a highly structured architecture and excellent stability. Experiments and ground-state differential charge calculations demonstrate that SubPc-Br and CdS form a built-in electric field during the self-assembly process, a critical factor in promoting the dissociation of electrons and holes. Additionally, this study utilized time-dependent density functional theory (TDDFT) to simulate the dynamic adsorption behavior of excited oxygen molecules on the SubPc-Br/CdS interface for the first time. The analysis of molecular charge differential density under different excited states proved that the addition of SubPc-Br molecules not only improves the photocorrosion resistance of CdS in an O2 adsorption environment but also enhances the production of advanced reactive oxygen species under the synergistic action of h+ and ·O2–. When subjected to visible light, the degradation efficiency of minocycline (MC) achieved 96.8% within 60 min and maintained 80.3% after 5 cycles. In summary, this study highlights the feasibility of creating advanced S-scheme heterojunction photocatalysts through the strategic incorporation of organic supramolecules with semiconductor catalysts.

Theoretical Investigation of Substitution Effect on the First Position of Coumarin Derivatives

AbstractDensity functional theory (DFT) and time‐dependent DFT (TD‐DFT) were used to investigate the linear and nonlinear optical properties of 1‐substituted coumarins. The molecular electrostatic potential plot, frontier molecular orbitals, and natural bond order analysis were used to study charge transfer properties. The bandgap exhibited an inverse relationship with the chemical potential (µ) and electrophilicity index (ω), while the chemical hardness (η) and hyperhardness (Γ) showed a direct relationship. First‐order hyperpolarizability (β0) and second‐order hyperpolarizability (γ) were directly correlated with the global reactivity descriptors μ and ω and inversely correlated with η and Γ.

Fluorescence Enhancement of Nonemissive Monodeprotonated Luteolin in a Poly(vinyl alcohol) Film.

Solid polymer matrixes can modulate the electronic states of embedded chromophores and have been widely used in flexible optoelectronic and optical materials. Luteolin is one of the most common natural flavonoids, and its neutral and monodeprotonated forms are nonemissive in aqueous solution induced by ultrafast excited-state proton transfer (ESPT) followed by nonradiative relaxation. In this study, we have incorporated luteolin into poly(vinyl alcohol) (PVA) films and studied their fluorescence behaviors. Neutral and one monodeprotonated luteolin coexist in the PVA film. Weak steady-state fluorescence of neutral luteolin peaking at about 440 nm is observed for the first time. In addition, the monodeprotonated luteolin in PVA film exhibits obvious fluorescence peaking at 500 nm, with a fluorescence quantum yield of as high as 0.4 and a fluorescence lifetime of as long as 2.4 ns. Time-dependent density functional theory calculations have determined that the ESPT of neutral luteolin is barrierless but that of monodeprotonated luteolin needs to surmount a barrier, explaining their distinct emission properties. These results indicate the modulation ability of the PVA film in both ground-state deprotonation and ESPT, broadening the application areas of the solid polymer matrix.

Ultrafast structural transition and electron-phonon/phonon–phonon coupling in antimony revealed by nonadiabatic molecular dynamics

Real-time time-dependent density-functional theory molecular dynamics (rt-TDDFT-MD) reveals the nonadiabatic dynamics of the ultrafast photoinduced structural transition in a typical phase-change material antimony (Sb) with Peierls distortion (PD). As the excitation intensity increases from 3.54% to 5.00%, three distinct structural transition behaviors within 1 ps are observed: no PD flipping, nonvolatile-like PD flipping, and nonstop back-and-forward PD flipping. Analyses on electron-phonon and phonon-phonon couplings indicate that the excitation-activated coherent A1gphonon mode by electron-phonon coupling drives the structural transition within several hundred femtoseconds. Then, the energy of coherent motions are transformed into that of random thermal motions via phonon-phonon coupling, which prevents the A1g-mode-like coherent structure oscillations. The electron-phonon coupling and coherent motions will be enhanced with increasing the excitation intensity. Therefore, a moderate excitation intensity that can balance the coherent and decoherent thermal movements will result in a nonvolatile-like PD flipping. These findings illustrate important roles of nonadiabatic electron-phonon/phonon-phonon couplings in the ultrafast laser-induced structural transitions in materials with PD, offering insights for manipulating their structures and properties by light.

Spectroscopic Properties and Reactivity of a MnIII-Hydroperoxo Complex that is Stable at Room Temperature.

Manganese catalysts that activate hydrogen peroxide have seen increased use in organic transformations, such as olefin epoxidation and alkane C-H bond oxidation. Proposed mechanisms for these catalysts involve the formation and activation of MnIII-hydroperoxo intermediates. Examples of well-defined MnIII-hydroperoxo complexes are rare, and the properties of these species are often inferred from MnIII-alkylperoxo analogues. In this study, we show that the reaction of the MnIII-hydroxo complex [MnIII(OH)(6Medpaq)]+ (1) with hydrogen peroxide and acid results in the formation of a dark-green MnIII-hydroperoxo species [MnIII(OOH)(6Medpaq)]+ (2). The formulation of 2 is based on electronic absorption, 1H NMR, IR, and ESI-MS data. The thermal decay of 2 follows a first order process, and variable-temperature kinetic studies of the decay of 2 yielded activation parameters that could be compared with those of a MnIII-alkylperoxo analogue. Complex 2 reacts with the hydrogen-atom donor TEMPOH two-fold faster than the MnIII-hydroxo complex 1. Complex 2 also oxidizes PPh3, and this MnIII-hydroperoxo species is 600-fold more reactive with this substrate than its MnIII-alkylperoxo analogue [MnIII(OOtBu)(6Medpaq)]+. DFT and time-dependent (TD) DFT computations are used to compare the electronic structure of 2 with similar MnIII-hydroperoxo and MnIII-alkylperoxo complexes.

OpenQP: A Quantum Chemical Platform Featuring MRSF-TDDFT with an Emphasis on Open-Source Ecosystem.

The OpenQP (Open Quantum Platform) is a new open-source quantum chemistry library developed to tackle sustainability and interoperability challenges in the field of computational chemistry. OpenQP provides various popular quantum chemical theories as autonomous modules such as energy and gradient calculations of HF, DFT, TDDFT, SF-TDDFT, and MRSF-TDDFT, thereby allowing easy interconnection with third-party software. A scientifically notable feature is the innovative mixed-reference spin-flip time-dependent density functional theory (MRSF-TDDFT) and its customized exchange-correlation functionals such as the DTCAM series of VAEE, XI, XIV, AEE, and VEE, which significantly expand the applicability scope of DFT and TDDFT. OpenQP also supports parallel execution and is optimized with BLAS and LAPACK for high performance. Future enhancements such as extended Koopman's theorem (EKT)-MRSF-TDDFT and spin-orbit coupling (SOC)-MRSF-TDDFT will further expand OpenQP's capabilities. Additionally, a Python wrapper PyOQP is provided that performs tasks such as geometry optimization, conical intersection searches, and nonadiabatic coupling calculations, among others, by prototyping the modules of the OpenQP library in combination with third-party libraries. Overall, OpenQP aligns with modern trends in high-performance scientific software development by offering flexible prototyping and operation while retaining the performance benefits of compiled languages like Fortran and C. They enhance the sustainability and interoperability of quantum chemical software, making OpenQP a crucial platform for accelerating the development of advanced quantum theories like MRSF-TDDFT.

Exploring the fascinating interplay of epigenetically modified DNA bases with two dimensional bare and P-doped Si2BN and BN sheets for biosensing applications: A compelling DFT perspective

Detecting epigenetically modified (EM) bases is crucial for disease detection, biosensing, and DNA sequencing. Two-dimensional P-doped Si2BN and BN sheets are used as sensing substrates in density functional theory (DFT) studies. Both the sheets are doped with a phosphorous atom at various atomic sites to examine the sheet's potential in detecting 5-hydroxymethylcytosine (5hmc), 5-methylcytosine (5mc), 7-methylguanine (7 mg) and 8-oxoguanine (8oxg) bases. Doping of the P atom in the Si2BN sheet improves the adsorption energy (Ead) of Ab+5hmc (−107.16 kcal/mol) and Ab+5mc (−78.36 kcal/mol), As+7 mg (−84.31 kcal/mol) in the gas and aqueous phase Ab+5hmc (−93.28 kcal/mol), An+7 mg (−78.92 kcal/mol) and As+5mc (−77.52 kcal/mol) respectively. Standard deviation (θ) indicates that As complexes have high θ values ranging from 4.55 to 37.77, suggesting a high likelihood of distinguishing the bases. The P-doped BN complexes exhibit noticeable work functional shifting (Δϕ%) recommended that they can be used as ϕ-based sensors. Time-dependent DFT results suggest that when EM bases interact with P-doped Si2BN complexes, significant blue shifts (hypsochromic) and red shifts (bathochromic) are observed in the visible and near-infrared spectrum. Hence, the above finding suggests that P-doped Si2BN sheets are highly effective for sensing EM bases and are recommended for DNA/RNA sequencing applications.