Dynamic Hyperpolarizabilities Research Articles

Superalkali-alkalide ion pairs δ+(M-HMHC)-M’ δ - (M, M’ = Li, Na and K) serving as high-performance NLO molecular materials

For the stable superalkali-alkalide ion pairs in alkalide solutions, a DFT study was performed to investigate the nonlinear optics (NLO) responses of δ +(M−HMHC)-M’ δ - (M, M’ = Li, Na and K). The NLO responses display obvious alkali metal atomic number dependence (M’). From δ +(M−HMHC)-Li δ - to δ +(M−HMHC)-K δ -, the increases of the static and dynamic first hyperpolarizabilities constitute a 1 ∼ 3 orders of magnitude improvement.

Superalkali-based alkalides Li3O@[12-crown-4]M (where M= Li, Na, and K) with remarkable static and dynamic NLO properties; A DFT study

Exploring new nonlinear optical materials with excess electron character is extremely important for promoting the application of excess electron compounds in nonlinear optics. Herein, by using density functional theory (DFT) computations, new superalkali-based alkalides Li3O@[12-crown-4]M− are designed as excess electron compounds. QTAIM studies suggest that the complexant interacts with alkali and superalkali clusters through non-covalent interactions. These complexes are thermodynamically stable and their interaction energies range from −33.40 ∼ −44.23 kcal mol-1. The alkalide nature of these compounds is guaranteed by their HOMOs values and NBO charge analysis. Being excess electron compounds, these alkalides shows potential electronic properties. Their HOMO-LUMO gaps ranging from 0.17–0.27 eV. With excellent properties, these complexes show remarkable total hyperpolarizability (βo) response (9.30×104–5.26×106au). Interestingly, the hyperpolarizability response is dependent on the size of alkali metals. The βvec values are quite comparable to total hyperpolarizability at the same level of theory. Furthermore, the hyperpolarizability calculated through two-level model (βtl) values show a trend similar to hyperpolarizability. Additionally, the dynamic hyperpolarizability response for EOPE effects is much pronounced at the dispersion frequency of 532 nm. The second hyperpolarizability response for the dc-Kerr constant is increased up to 2.75 × 1012 au which is much higher than those of previously reported alkalides. Strikingly, the frequency-dependent NLO response shows dependence on alkalide character rather than the size of alkali metal (M). Moreover, the βHRS value is recorded up to 2.16 × 106 au. The significant dipolar contribution to hyperpolarizabilities Φβ(J = 1) are observed for these complexes.

Demonstrating the Potential of Alkali Metal-Doped Cyclic C6O6Li6 Organometallics as Electrides and High-Performance NLO Materials.

In this report, the geometric and electronic properties and static and dynamic hyperpolarizabilities of alkali metal-doped C6O6Li6 organometallics are analyzed via density functional theory methods. The thermal stability of the considered complexes is examined through interaction energy (Eint) calculations. Doping of alkali metal derives diffuse excess electrons, which generate the electride characteristics in the respective systems (electrons@complexant, e–@M@C6O6Li6, M = Li, Na, and K). The electronic density shifting is also supported by natural bond orbital charge analysis. These electrides are further investigated for their nonlinear optical (NLO) responses through static and dynamic hyperpolarizability analyses. The potassium-doped C6O6Li6 (K@C6O6Li6) complex has high values of second- (βtot = 2.9 × 105 au) and third-order NLO responses (γtot = 1.6 × 108 au) along with a high refractive index at 1064 nm, indicating that the NLO response of the corresponding complex increases at a higher wavelength. UV–vis absorption analysis is used to confirm the electronic excitations, which occur from the metal toward C6O6Li6. We assume that these newly designed organometallic electrides can be used in optical and optoelectronic fields for achieving better second-harmonic-generation-based NLO materials.

Excited-State Dynamics and Nonlinear Optical Properties of Hyperpolarizable Chromophores Based on Conjugated Bis(terpyridyl)Ru(II) and Palladium and Platinum Porphyrinic Components: Impact of Heavy Metals upon Supermolecular Electro-Optic Properties.

A new series of strongly coupled oscillators based upon (porphinato)Pd, (porphinato)Pt, and bis(terpyridyl)ruthenium(II) building blocks is described. These RuPPd, RuPPt, RuPPdRu, and RuPPtRu chromophores feature bis(terpyridyl)Ru(II) moieties connected to the (porphinato)metal unit via an ethyne linker that bridges the 4'-terpyridyl and porphyrin macrocycle meso-carbon positions. Pump-probe transient optical data demonstrate sub-picosecond excited singlet-to-triplet-state relaxation. The relaxed lowest-energy triplet (T1) excited states of these chromophores feature absorption manifolds that span the 800-1200 nm spectral region, microsecond triplet-state lifetimes, and large absorptive extinction coefficients [ε(T1 → Tn) > 4 × 104 M-1 cm-1]. Dynamic hyperpolarizability (βλ) values were determined from hyper-Rayleigh light scattering (HRS) measurements carried out at several incident irradiation wavelengths over the 800-1500 nm spectral region. Relative to benchmark RuPZn and RuPZnRu chromophores which showed large βHRS values over the 1200-1600 nm range, RuPPd, RuPPt, RuPPdRu, and RuPPtRu displayed large βHRS values over the 850-1200 nm region. Generalized Thomas-Kuhn sum (TKS) rules and experimental hyperpolarizability values were utilized to determine excited state-to-excited state transition dipole terms from experimental electronic absorption data and thus assessed frequency-dependent βλ values, including two- and three-level contributions for both βzzz and βxzx tensor components to the RuPPd, RuPPt, RuPPdRu, and RuPPtRu hyperpolarizability spectra. These analyses qualitatively rationalize how the βzzz and βxzx tensor elements influence the observed irradiation wavelength-dependent hyperpolarizability magnitudes. The TKS analysis suggests that supermolecules related to RuPPd, RuPPt, RuPPdRu, and RuPPtRu will likely feature intricate dependences of experimentally determined βHRS values as a function of irradiation wavelength that derive from substantial singlet-triplet mixing, and complex interactions among multiple different β tensor components that modulate the long wavelength regime of the nonlinear optical response.

Synthesis, structural determination, Hirshfeld surface analysis, 3D energy frameworks, electronic and (static, dynamic) NLO properties of o-Nitroacetanilide (o-NAA): A combined experimental and quantum chemical study

o-Nitroacetanilide (o-NAA), an organic crystal, was synthesized and fully characterized by means of single-crystal XRD, FTIR, UV–visible,1H and 13C NMR spectroscopic techniques. Its molecular structure was optimized, the subsequent electronic properties, the spectroscopic spectra were quantified using quantum chemical computations by density functional theory calculations and compared with the experimental results. Furthermore, the Mulliken atomic charges were estimated andthe molecular electrostatic potential map was plotted in order to identify the chemical reactive sites. To study the nonlinear optical (NLO) activity of o-NAA, the electric dipole moment, the static and dynamic polarizability and hyperpolarizabilities were computed indicating that it could be considered as a good candidate for NLO applications. The hydrogen bonding and the non-classical intermolecular interactions were investigated by performing a Hirshfeld surface analysis and their contributions were analyzed via the 2D-Fingerprint plots, thus revealing that the crystal structure of the studied molecule is mainly built up of H…H, H…O/O…H, H…C/C…H and C…O/O…C close contacts. From the 3D-molecular energy frameworks analysis, the lattice energy of the compound was found to be − 95.15 kJ.mol−1, and has exhibited stabilizing strong CH…O, NH…C, lp…lp, lp…π and π…π interactions.

Nonlinear optical properties of a new panchromatic series of water-soluble bicationic push-pull fluorophores

Six water-soluble bications, characterized by a symmetric A+-π-D-π-A+ structure, were synthesized and comprehensively studied for their absorption and fluorescence properties, and their nonlinear optical response. Generally, the photobehavior exhibited by the six systems was found to be dependent on the molecular dimensionality and conjugation, unveiling the role of different electron-donor (dimethoxy-phenylene vs bithiophene) and electron-acceptor (methyl-pyridinium, methyl-quinolinum, and pyrimidin-pyridinium) substituents bound in different positions (ortho/para). Steady-state measurements revealed this series as a panchromatic family of dyes with noticeable absorption and emission abilities, covering the entire visible spectrum - from the near-ultraviolet to the near-infrared spectral region. Femtosecond-resolved spectroscopy disclosed the presence of ultrafast intramolecular charge transfer processes, as also predicted by TD-DFT calculations, from the central electron-rich moiety of the molecule towards the two lateral positively charged units. Further and for the first time, a solvatochromic method was successfully applied to this kind of quadrupolar double-charged compounds in order to estimate their static and dynamic second-order hyperpolarizability coefficients. Thanks to their appreciable fluorescence capability, significant Two-Photon Absorption cross-sections were also measured for all six dyes by means of the Two-Photon Excited Fluorescence technique. These findings, together with their good water solubility, designate these eye-catching fluorophores as potential candidates for bioimaging applications.

Turning diamondoids into nonlinear optical materials by alkali metal Substitution: A DFT investigation

Electronic properties, absorption spectra and nonlinear optical properties of alkali metal substituted diamantanes are presented. A significant reduction in HOMO-LUMO gap has been observed by alkali metal substitution. K@CHa has the lowest H-L gap of 1.64 eV as compared to 8.88 eV for pristine diamantane. A remarkable increase in the first hyperpolarizability (βo) has been observed due to the substitution of alkali metals. Among these structures, K substituted complexes show the largest first hyperpolarizability (25526–36328 a.u). This significant increase in the first hyperpolarizability (βo) is attributed to low crucial transition energy (ΔE). K@CHa has the lowest ΔE value (2.06 eV) which results in the highest βo value (36328 a.u.) for K@CHa. Furthermore, frequency-dependent hyperpolarizability calculations have been carried out using 1906 nm and 1340 nm frequencies for commonly used lasers. The values of dynamic hyperpolarizabilities are greater than those of static ones for the majority of the substituted systems. This suggests the application of the proposed complexes under different frequencies of incident radiations. The substitution of alkali metals leads to the shift in absorption from ultraviolet to the visible region. Bathochromic shifts in the absorption spectra are observed with an increase in the size of alkali metal atom (λmax = 600 nm for K@CHa). This study provides an efficient approach to design high-performance NLO materials having extensive applications in the field of electronics and optoelectronics.

Oxacarbon superalkali C3X3Y3 (X = O, S and Y = Li, Na, K) clusters as excess electron compounds for remarkable static and dynamic NLO response

An intriguing class of excess electron oxacarbon superalkali clusters is explored for nonlinear optical response through density functional theory (DFT) methods at CAM-B3LYP/6–311++G(d,p). These superalkali clusters shows noticeable binding energies per atom (Eb) which reveals their thermodynamic stabilities (−86.45 ∼ −119.44 kcal mol−1). The obtained significant VIPs values also suggest the electronic stability of these clusters. The VIP values range from 2.06 eV to 3.42 eV. These clusters show remarkable electronic properties and their HOMO-LUMO gaps (EH-L) are significantly reduced. The lowest H-L gap of 0.96 eV is obtained for C3O3K3 while the highest H-L gap of 2.07 eV is calculated for C3S3Li3. The obtained PDOS spectra further provide evidence for the superior electronic properties of these clusters. The clusters show excellent nonlinear optical properties as revealed from remarkable values (1.6 × 106 au) of static first hyperpolarizability. The controlling factors for hyperpolarizability are also explored by using conventional two-level model. The calculated values of βo are correlated nicely with βtl. The crucial excitation energy is the key factor in controlling the first hyperpolarizability. In these excess electron clusters, the second hyperpolarizability (γo) response increases up to 4.3 × 109 au. Moreover, the calculated scattering hyperpolarizability (βHRS) values are quite significant in these clusters and the highest value of 1.3 × 106 au is calculated for C3S3K3. Additionally, these clusters also possess larger dynamic nonlinearities. The dynamic second hyperpolarizability with dc-Kerr effect increases up to 1.0 × 1011 au. The remarkable values for refractive index (n2) also suggest the excellent nonlinearity of these superalkali clusters.

Solvent effect on static and dynamic first hyperpolarizability of azochromophore with tricyanopyrrole acceptor moiety

Solvent effect on molecular nonlinear optical (NLO) characteristics of azochromophore with tricyanopyrrole acceptor, AAB-TCP, is estimated within different models: polarizable continuum model (PCM), supermolecule (SM), semicontinuum (SC). The values of first hyperpolarizability are calculated by TD-DFT at M06-2X/aug-cc-pVDZ level; the dynamic characteristics are evaluated at 0.65 eV frequency. Molecular dynamics of AAB-TCP solution in acetone (at concentration 2·10−2 mol%) is performed in amorphous cell what allowed to reveal different types of hydrogen-bonded supermolecules formed by AAB-TCP and one or two acetone molecules; for four supermolecules the first hyperpolarizability values are calculated. Solvent effect accounted within the PCM approach causes almost 4 times increase of static first hyperpolarizability. The account of direct interaction within supermolecule model results in the growth of first hyperpolarizability and describes the solvent effect partly; the estimations at semicontinuum level show further increase (by 40% for static and 50% for dynamic cases) of first hyperpolarizability compared to the PCM values, thus demonstrating the role of solute-solvent hydrogen bonding.

Quantum Chemical Computational Studies on N-Acetylglycine Single Crystal for Potential Applications

The crystals of N-acetylglycine were obtained by the slow evaporation of an aqueous solution at room temperature. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system with centro symmetric space group P21/c with lattice parameters are a = 4.8410(10) Å, b = 11.512(2) Å, c = 9.810(2) Å, α = 90º, β = 97.02(3)º, γ = 90º and V = 542.61 (Å)3. Quantum chemical computations have been performed on the grown crystal with DFT-B3LYP/6-311++G(d,p) basis set. The theoretically obtained geometrical parameters and vibrational frequencies are in close agreement with experimental data. HOMO-LUMO energy gap and molecular electrostatic potential map has also been calculated. The static and dynamic polarizability and first hyperpolarizability both were calculated to comprehend the potential applications of N-acetylglycine in nonlinear optics. Hirshfeld surface analysis has been performed to study the inter and intra molecular interactions between the molecule. Thus in present study, the structure-property relationship of novel N-acetylglycine molecule is studied for future nonlinear optical applications through experimental and theoretical approach.

Quantum computation of molecular response properties

Accurately predicting response properties of molecules such as the dynamic polarizability and hyperpolarizability using quantum mechanics has been a long-standing challenge with widespread applications in material and drug design. Classical simulation techniques in quantum chemistry are hampered by the exponential growth of the many-electron Hilbert space as the system size increases. In this work, we propose an algorithm for computing linear and nonlinear molecular response properties on quantum computers, by first reformulating the target property into a symmetric expression more suitable for quantum computation via introducing a set of auxiliary quantum states, and then determining these auxiliary states via solving the corresponding linear systems of equations on quantum computers. On one hand, we prove that using the quantum linear system algorithm [Harrow et al., Phys. Rev. Lett. 103, 150502 (2009)] as a subroutine the proposed algorithm scales only polynomially in the system size instead of the dimension of the exponentially large Hilbert space, and hence achieves an exponential speedup over existing classical algorithms. On the other hand, we introduce a variational hybrid quantum-classical variant of the proposed algorithm, which is more practical for near-term quantum devices.

Molecular structure, linear optical, second and third-order nonlinear optical properties of two non-centrosymmetric thiophene‐chalcone derivatives

Two chalcones, (2E)-1-(5-bromothiophen-2-yl)-3-(3-fluorophenyl) prop-2-en-1-one (3F5B2SC) and (2E)-1-(5-bromothiophen-2-yl)-3-(4-methoxyphenyl) prop-2-en-1-one (4M5B2SC) were synthesised and crystallized by slow evaporation solution growth technique to investigate their structural, linear optical, thermal and nonlinear optical properties. Initially, the structures of 3F5B2SC and 4M5B2SC were confirmed by FT-IR and NMR (1H and 13C NMR) spectroscopic studies. Detail solid state structures of these grown crystals were determined by single crystal XRD data analysis. Both the chalcones are crystallized in the non-centrosymmetric monoclinic crystal system. The thermal analysis (DSC, TGA, DTA and DTG) revealed that 3F5B2SC and 4M5B2SC molecules are thermally stable upto their melting points for solid state studies. The linear optical properties of these chalcones were studied in the UV–Vis-NIR region. The estimated direct energy band gap of the molecules by Tauc's plot (4.7 eV for 3F5B2SC and 4.2 eV for 4M5B2SC) are comparable with HOMO-LUMO gaps. The MEP and NBO of both the molecules are studied by DFT method. The second harmonic generation (SHG) efficiency of 4M5B2SC and 3F5B2SC determined by Kurtz-Perry powder method is found to be 5.3 and 4.2 times that of urea, respectively. Third-order NLO parameters, such as nonlinear absorption coefficient (β = ~ 10−4 cm/W), nonlinear refractive index (n2 = ~ 10−9 cm2/W), susceptibility (χ(3)= ~ 10−7 esu) and molecular hyperpolarizability (γh = ~ 10−27 esu) were determined unambiguously from Z-scan experimental data analysis. The molecules exhibited optical limiting behaviour for continuous wave (CW) laser operating at 532 nm wavelength. Computationally, the dipole moment, static and dynamic polarizability and hyperpolarizability of both the chalcones were determined by TD-DFT and TD-HF method. The obtained results suggest that the studied thiophene- chalcones may be used in optical device as frequency generator, optical limiter and optical switch.

Synthesis, molecule growth, characterization, theoretical studies and nonlinear optical properties of new chalcone derivative containing thiophene moiety for optical device applications

A new organic nonlinear optical chalcone derivative-1-(5-bromothiophene-2-yl)-3-(3-methoxyphenyl) prop-2-en-1-one (3MO5B2SC) molecule has been grown by slow evaporation technique. Theoretically DFT method was used to study optimized structure of the molecule and compare with reported XRD data. The structure of the molecule has been confirmed by the experimental and computed FTIR and H1 NMR spectrum studies. The melting point (117 °C) and thermal stability (273 °C) of the molecule have been determined using DSC, TGA, DTA and DTG. The optical absorption spectrum revels that molecule has lower optical cut-off wavelength of 410 nm recorded by UV–Vis–NIR spectrophotometer and 480 nm calculated by DFT. The band gap calculated from experimental data and theoretical HOMO–LUMO plots is same (3.3 eV). The global chemical reactivity descriptor (GCRD) of the sample has been calculated. The nonlinear parameters such as nonlinear absorption coefficient (β ~ 10−4 cm/W), nonlinear refraction index (n2 ~ 10−8 cm2/W) and third-order nonlinear susceptibilities (χ(3) ~ 10−6 esu) and molecular hyperpolarizability (γh ~ 10−26 esu) were measured under diode-pumped continuous wave Nd:YAG laser at 532 nm wavelength. The static electric dipole moment (μ), polarizability (α), first hyperpolarizability (β), static and dynamic second hyperpolarizability (γh) have been calculated theoretically and compared with experimental values. The experimental and theoretical nonlinear parameters are many times higher than urea molecule. The mean polarizability, total polarizability, first-order hyperpolarizability and static second hyperpolarizability value of the molecule is 20, 7.5, 17 and 91 times higher than standard urea, respectively. The nonlinearity exhibited by this molecule exploited for studying its optical limiting behaviour. The structure and its corresponding properties prompt that it can be used as nonlinear optical devise applications.

A generalized few-state model for the first hyperpolarizability.

The properties of molecules depend on their chemical structure, and thus, structure-property relations help design molecules with desired properties. Few-state models are often used to interpret experimental observations of non-linear optical properties. Not only the magnitude but also the relative orientation of the transition dipole moment vectors is needed for few-state models of the non-linear optical properties. The effect of the relative orientation of the transition dipole moment vectors is called dipole alignment, and this effect has previously been studied for multiphoton absorption properties. However, so far, no such studies are reported for the first hyperpolarizability. Here, we present a generalized few-state model for the static and dynamic first hyperpolarizability β, accounting for the effect of dipole alignment. The formulas derived in this work are general in the sense that they can be used for any few-state model, i.e., a two-state model, a three-state model, or, in general, an n-state model. Based on the formulas, we formulate minimization and maximization criteria for the alignment of transition dipole moment vectors. We demonstrate the importance of dipole alignment by applying the formulas to the static first hyperpolarizability of ortho-, meta-, and para-nitroaniline. The formulas and the analysis provide new ways to understand the structure-property relationship for β and can hence be used to fine-tune the magnitude of β in a molecule.

Effect of dimer formation via hydrogen bonding on static and dynamic nonlinear optical characteristics of chromophores

AbstractThe effect of head‐to‐tail azochromophore dimer formation on the values of static and dynamic first hyperpolarizability is studied on the basis of calculations performed at M06‐2X/aug‐cc‐pVDZ and ωB97X‐D/aug‐cc‐pVDZ computational levels; the results are compared with those obtained at second‐order Moller‐Plesset pertubation theory (MP2)/aug‐cc‐pVDZ. Azochromophores DO3 and AAB‐DCV, participating in the dimer formation, contain nitro‐ or dicyanovinylene acceptor moieties. The structure of the studied dimers is obtained at the B3LYP‐D3/6‐31++G (d,p) level with basis set superposition error (BSSE) correction. Dynamic first hyperpolarizabilities are calculated at radiation frequencies of 0.65 eV, 0.918 eV and 1.165 eV. The essential effect of dimer formation is demonstrated: it results in almost a 3.5 times increase of the first hyperpolarizability. In the series D1‐D2‐D3, β(2ω) values at 0.65 eV increase in a way similar to the static case: β(2ω) for D2 and D3 are 1.5 and 1.8 times higher than that for D1. The notable resonance enhancement of β(2ω) for the studied hydrogen‐bonded dimers is demonstrated at radiation frequency of 1.165 eV.

Dynamic multipolar polarizabilities and hyperpolarizabilities of the Sr lattice clock

The progress in optical clock with uncertainty at a level of $10^{-18}$ requires unprecedented precision in estimating the contribution of multipolar and higher-order effects of atom-field interactions. Current theoretical and experimental results of dynamic multipolar polarizabilities and hyperpolarizabilities at the magic wavelength for the Sr clock differ substantially. We develop a combined approach of the Dirac-Fock plus core polarization (DFCP) and relativistic configuration interaction (RCI) methods to calculate dynamic multipolar polarizabilities and hyperpolarizabilities of the Sr atom. Our differential dynamic hyperpolarizability at the magic wavelength is $-2.09(43)\times10^{7}$ a.u., which is consistent with the existing theoretical and experimental results. Our differential multipolar polarizability is $2.68(94)\times 10^{-5}$ a.u., which validates independently the theoretical work of Porsev {\em et al.} [Phys. Rev. Lett. 120, 063204 (2018)], but different from recent measurement of Ushijima {\em et al.} [Phys. Rev. Lett. 121, 263202 (2018)].

Metal ions doped into merocyanine form of coumarin derivatives: nonlinear optical molecular switches.

In the present study, DFT calculations are carried out on domestically designed 7-methyl-2-phenyl-5'H-spiro[chromene-4,2'-chromeno[3,4-e][1,3]oxazin]-5'-one spiropyran and merocyanine derivatives to recognize alkali and alkaline earth metal ions. Detection of these metal ions can be attained by exploiting the variation of the second-order nonlinear optical properties. Merocyanine forms of these derivatives exhibit the ability to complex with different metal ions (Li+, Na+, K+, and Ca2+), which is associated with large contrasts in the hyper-Rayleigh scattering (HRS) response as a function of metal size and charge. Interestingly, in this study, Mero-Li+ shows significant nonlinear optical response with dynamic HRS first hyperpolarizability amounting to 7607a.u., which is about nine times higher than its corresponding spiro form (846a.u.) at the CAM-B3LYP/6-311G* level of theory. The present investigation clarifies the effect of metal nature on the enhancement of the first hyperpolarizability between the closed and open forms of the studied coumarin derivatives. Graphical abstract The coumarin-based compound 3 demonstrate the higher second-order NLO responses as a function of metal cation size and charges. Complexation of smaller alkali metal ions leads to the formation of stronger metal-ligand bonds, larger geometrical relaxations and significant enhancement of the HRS first hyperpolarizabilities. This present investigation elucidates the effect of metal nature on the enhancement of the first hyperpolarizability between the closed and open forms of studied coumarin derivatives.

Effect of acceptor moieties on static and dynamic first hyperpolarizability of azobenzene chromophores

The effect of acceptor on static and dynamic first hyperpolarizability, β, of trans- and cis-isomers of azochromophores AAB-DCV and AAB-TCV is studied. Calculations were performed by MP2 and DFT with three density functionals: M06-2X, CAM-B3LYP and ωB97X-D in gas phase and chloroform. Dynamic first hyperpolarizabilities were calculated by TD-DFT at 1.165 and 0.65 eV. The first hyperpolarizability values for trans-isomers are approximately three times greater than those for cis-isomer; solvent effect is essential comprising 2.7 and 3.2 times growth for static values for AAB-DCV and AAB-TCV, respectively, the corresponding dynamic estimations for βtot(2ω) being slightly smaller (2.2 and 2.6 times).

Optical and nonlinear optical properties of Ln(Tp)2, where Ln = La,…,Lu and Tp = tris(pyrazolyl)borate: a DFT+TD-DFT study

DFT calculations of electronic, structural, thermodynamic properties, magnetic moment, static and dynamic polarizability and hyperpolarizability of Ln(Tp)2 (Ln = rare earths, Tp = ring-unsubstituted tris(pyrazolyl)borate) complexes.

Effect of fluorination on bandgap, first and second order hyperpolarizabilities in lithium substituted adamantane: A time dependent density functional theory

Time dependent density functional theory is used to systematically examine the band gap variation of Li-substituted adamantanes upon fluorination. It is realized that the absorption wavelength of Li-Adamantane can be fine tuned within UV–Visible region by changing the degree of fluorination. The static and dynamic hyperpolarizabilities of fluorinated Li-Adamantane derivatives were computed using coupled perturbed Kohn Sham theory. In this article, we report Pockel, dc-Kerr, ESHG, degenerate four wave mixing coefficients and nonlinear refractive indices from the first and second order hyperpolarizability calculations. A high positive nonlinear refractive index and significant second harmonic generation efficiency at Nd:YAG Laser wavelength are observed in F3Li-Adm derivative.