Conical Intersection Point Research Articles

Turn on the luminescence channel by the suppression of conical intersection process for the sulfur-containing hydrogen-bonded molecules

The sulfur-containing hydrogen bonds exhibit notable potential in gene and protein engineering. As an important research direction of sulfur-containing hydrogen bonding dynamics, the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton has garnered significant interest. Recently, Chou et al. synthesized a series of sulfur-containing H-bonded molecules, inclusive of 3-thiolflavone (3 TF), its trifluoromethyl derivative (3FTF), and its diethylamino derivative (3NTF), thereby inaugurating a new chapter in the ESIPT reaction of the thiol proton. Nevertheless, many open issues cannot be answered solely by experimental means and call for a detailed theoretical investigation, especially the relationship between the molecular excited-state properties and different luminescence properties of the three molecules. Herein, we validate that the molecules undergo the ESIPT reaction of the thiol proton and identify the time scale through the time-dependent density functional theory (TDDFT) calculation. Moreover, employing the spin-flip TDDFT approach, the analysis of the non-radiative transition process reveals that difference in Gibbs free energy of activation (ΔG⧧) for the transition from Frank-Condon point to minimum energy conical intersection (MECI) point primarily accounts for the different luminescence properties of the three molecules. Besides, we also reveal the reason for the abnormal blue-shifted fluorescence of the 3NTF in the aggregated state by the ONIOM (TDDFT: UFF) strategy. These findings are favorable to understanding the luminescence mechanism of sulfur-containing H-bonded molecules and provide a reference for the synthesis and design of the luminescent materials based on the molecules with thiol proton transfer properties.

Calculation of Excited State Internal Conversion Rate Constant Using the One-Effective Mode Marcus-Jortner-Levich Theory.

In this article, the one-effective mode Marcus-Jortner-Levich (MJL) theory and the classical Marcus theory for electron transfer were applied to estimate the internal conversion rate constant, kIC, of organic molecules and a Ru-based complex, all belonging to the Marcus inverted region. For this, the reorganization energy was calculated using the minimum energy conical intersection point to account for more vibrational levels, correcting the density of states. The results showed good agreement with experimental and theoretically determined kIC, with a small overestimation by the Marcus theory. Also, molecules less dependent on the solvent effects, like benzophenone, presented better results than molecules with an expressive dependence, like 1-aminonaphthalene. Moreover, the results suggest that each molecule possesses unique normal modes leading to the excited state deactivation that does not necessarily match the X-H bond stretching, as previously suggested.

Modeling Light-Induced Chromophore Hydration in the Reversibly Photoswitchable Fluorescent Protein Dreiklang.

We report the results of a computational study of the mechanism of the light-induced chemical reaction of chromophore hydration in the fluorescent protein Dreiklang, responsible for its switching from the fluorescent ON-state to the dark OFF-state. We explore the relief of the charge-transfer excited-state potential energy surface in the ON-state to locate minimum energy conical intersection points with the ground-state energy surface. Simulations of the further evolution of model systems allow us to characterize the ground-state reaction intermediate tentatively suggested in the femtosecond studies of the light-induced dynamics in Dreiklang and finally to arrive at the reaction product. The obtained results clarify the details of the photoswitching mechanism in Dreiklang, which is governed by the chemical modification of its chromophore.

The Second Excited Triplet‐State Facilitates TADF and Triplet–Triplet Annihilation Photon Upconversion via a Thermally Activated Reverse Internal Conversion

AbstractRecent years have seen a surge in organic emitters that exhibit thermally activated delayed fluorescence (TADF) behavior owing to their high exciton utilization efficiency, low biological toxicity, etc. However, the existing TADF channel is insufficiently well developed as to design high‐performance materials especially in the high‐lying triplet state mediated reverse intersystem crossing process. A thermally activated reverse internal conversion (TARIC) pathway is reported here, which can achieve effective population transfer from T1 to T2 states via conical intersection point with the barrier of 3.81 kcal mol−1. On this basis, the mediated T2 state facilitates the TADF and triplet–triplet annihilation photon upconversion (TTA–UC) channel. Furthermore, benefited from the TARIC pathway, the designed 2′,7′‐dichlorofluorescein (DCF) derivative DCF−MPYM−Me photosensitizer presents an excellent upconversion efficiency of 13.6%. The high upconversion efficiency is the best performance in purely organic TADF photosensitizers without heavy atoms in TTA−UC systems.

Analytical Energy Gradient for State-Averaged Orbital-Optimized Variational Quantum Eigensolvers and Its Application to a Photochemical Reaction.

Elucidating photochemical reactions is vital to understanding various biochemical phenomena and developing functional materials such as artificial photosynthesis and organic solar cells, albeit with notorious difficulty in both experiments and theories. The best theoretical way so far to analyze photochemical reactions at the level of ab initio electronic structure is the state-averaged multiconfigurational self-consistent field (SA-MCSCF) method. However, the exponential computational cost of classical computers with the increasing number of molecular orbitals hinders applications of SA-MCSCF for large systems we are interested in. Utilizing quantum computers was recently proposed as a promising approach to overcome such computational cost, dubbed as state-averaged orbital-optimized variational quantum eigensolver (SA-OO-VQE). Here, we extend a theory of SA-OO-VQE so that analytical gradients of energy can be evaluated by standard techniques that are feasible with near-term quantum computers. The analytical gradients, known only for the state-specific OO-VQE in previous studies, allow us to determine various characteristics of photochemical reactions such as the conical intersection (CI) points. We perform a proof-of-principle calculation of our methods by applying it to the photochemical cis-trans isomerization of 1,3,3,3-tetrafluoropropene. Numerical simulations of quantum circuits and measurements can correctly capture the photochemical reaction pathway of this model system, including the CI points. Our results illustrate the possibility of leveraging quantum computers for studying photochemical reactions.

Unraveling the Bonding Nature Along the Photochemically Activated Paterno-Büchi Reaction Mechanism.

The photochemically activated Paterno-Büchi reaction mechanism following the singlet excited-state reaction path was analyzed based on a bonding evolution framework. The electronic rearrangements, which describe the mechanism of oxetane formation via carbon-oxygen attack (C-O), comprises of the electronic activation of formaldehyde and accumulation of pairing density on the O once the reaction system is approaching the conical intersection point. Our theoretical evidence based on the ELF topology shows that the C-O bond is formed in the ground-state surface (via C-O attack) returning from the S1 surface accompanied by 1,4-singlet diradical formation. Subsequently, the reaction center is fully activated near the transition state (TS), and the ring-closure (yielding oxetane) involves the C-C bond formation after the TS. For the carbon-carbon attack (C-C), both reactants (formaldehyde and ethylene) are activated, leading to C-C bond formation in the S1 excited state before reaching the conical intersection region. Finally, the C-O formation occurs in the ground-state surface, resulting from the pair density flowing primarily from the C to O atom.

Excited state trans-cis photoisomerization via non-adiabatic dynamics of novel UVB protective sunscreens

In this work, we verified that the newly synthesized octyl urocanate compounds (U1 and U2) can significantly absorb UVB and confirmed their excellent light stability. In addition, we combined the Proton Nuclear Magnetic Resonance (1HNMR) and Time-Dependent Density Functional Theory (TDDFT) calculation methods to clearly explain the UV protection mechanism of U1 and U2. Octyl urocanate can be excited to an excited state after absorbing ultraviolet light in the UVB region. After that, the isomerized molecules at the conical intersection point (CI) between the potential energy surfaces (PESs) of the S1 and S0 states, rapidly relax to the ground state from the S1 excited state in the form of a non-radiative transition. Ultrafast trans-cis photoisomerization can be carried out in a very short time. We found the characteristic peak of cis-U1 from the NMR of trans-U1 after being irradiated by the laser. Therefore, the energy absorbed by U1 and U2 can be quickly consumed through the non-radiative photoisomerization process. Therefore, we believe that octyl urocanate U1 and U2 are very good potential sunscreen molecules that absorb UVB.

Unveiling the nonadiabatic photoisomerization mechanism of hemicyanines for UV photoprotection

In this work, the nonadiabatic energy relaxation mechanism of hemicyanines for UV photoprotection were investigated by using the density functional theory (DFT) and time-dependent density functional theory (TDDFT) method for the first time. The absorption spectra and potential energy surfaces (PESs) of four hemicyanines with different positions of substituents were presented. The maximum absorption peaks of the four hemicyanines are located in the UVA region. In addition, all these hemicyanine molecules also have light absorption in both the UVB and UVC regions. At the same time, we found that the trans–cis photoisomerization PESs of all these hemicyanines have a significant conical intersection (CI) point between the first excited state and the ground state. Herein, it was first demonstrated that the UV energy absorbed by the hemicyanines could be dissipated nonadiabatically through the CI point by using the trans–cis photoisomerization dynamics mechanism. This work proves that hemicyanines have the possibility to be applied for UV photoabsorbers, and provides important basis for designing new type of hemicyanines for UV photoprotection.

Strong static and dynamic Jahn-Teller and pseudo-Jahn-Teller effects in niobium tetrafluoride.

We present a first-principles study of the static and dynamic aspects of the strong Jahn-Teller (JT) and pseudo-JT (PJT) effects in niobium tetrafluoride, NbF4, in the manifold of its electronic ground state, 2E, and its first excited state, 2T2. The complex topography of the full-dimensional multi-sheeted adiabatic JT/PJT surfaces is analyzed computationally at the complete-active-space self-consistent-field (CASSCF) and multireference second-order perturbation levels of electronic structure theory, providing a detailed characterization of minima, saddle points, and minimum-energy conical intersection points. The calculations reveal that the tetrahedral (Td) configuration of NbF4 undergoes strong JT distortions along the bending mode of e symmetry, yielding tetragonal molecular structures of D2d symmetry with Td → D2d stabilization energies of about 2000 cm-1 in the X̃2E state and about 6400 cm-1 in the Ã2T2 state. In addition, there exists strong X̃2E-Ã2T2 PJT coupling via the bending mode of t2 symmetry, which becomes important near the crossing seam of the X̃2E and Ã2T2 potential energy surfaces. A five-state five-mode JT/PJT vibronic-coupling Hamiltonian is constructed in terms of symmetry-invariant polynomial expansions of the X̃2E and Ã2T2 diabatic potential energy surfaces in the e and t2 bending coordinates. The parameters of the Hamiltonian are determined by a least-squares fit of its eigenvalues to the CASSCF ab initio data. The vibronic spectra and the time evolution of adiabatic electronic population probabilities are computed with the multi-configuration time-dependent Hartree method. The complexity of the spectra reflects the effects of the exceptionally strong E × e and T2 × e JT couplings and (E + T2) × (e + t2) PJT coupling. The time evolution of the populations of the adiabatic electronic states after the initial preparation of the Ã2T2 state reveals the femtosecond nonadiabatic dynamics through a multidimensional seam of conical intersection. These results represent the first study of the static and dynamical JT/PJT effects in the X̃2E and Ã2T2 electronic states of NbF4.

Modeling photophysical properties of the bacteriophytochrome-based fluorescent protein IFP1.4.

An enhanced interest in the phytochrome-based fluorescent proteins is explained by their ability to absorb and emit light in the far-red and infra-red regions particularly suitable for bioimaging. The fluorescent protein IFP1.4 was engineered from the chromophore-binding domain of a bacteriophytochrome in attempts to increase the fluorescence quantum yield. We report the results of simulations of structures in the ground S0 and excited S1 electronic states of IFP1.4 using the methods of quantum chemistry and quantum mechanics/molecular mechanics. We construct different protonation states of the biliverdin (BV) chromophore in the red-absorbing form of the protein by moving protons from the BV pyrrole rings to a suitable acceptor within the system and show that these structures are close in energy but differ by absorption bands. For the first time, we report structures of the minimum energy conical intersection points S1/S0 on the energy surfaces of BV in the protein environment and describe their connection to the local minima in the excited S1 state. These simulations allow us to characterize the deactivation routes in IFP1.4.

Ultrafast spectroscopic study on non-adiabatic UV protection mechanism of hemicyanines

In this work, we firstly elucidated the ultra-violet light protection dynamics mechanism of the typical hemicyanines, i.e. Hemicy and DHemicy, by combining the theoretical calculation method and the transient absorption spectra. It is theoretically and experimentally demonstrated that both Hemicy and DHemicy have strong absorption in UVC (200−280 nm), UVB (280−300 nm), and UVA (320−400 nm) regions. More-over, after absorbing energy, Hemicy and DHemicy can jump into the excited states. Subsequently, Hemicy and DHemicy relax to S0 states from S1 states rapidly by the non-adiabatic transition at the conical intersection point between the potential energy curves of S1 and S0 states, and are accompanied by the trans-cis photoisomerism. The transient absorption spectra show that trans-cis photoisomerization occur within a few picoseconds. Thus, the ultraviolet energy absorbed by Hemicy and DHemicy could be relaxed ultrafastly by the non-adiabatic trans-cis photoisomerization processes.

Multidimensional Structure Conformation of Persulfurated Benzene for Highly Efficient Phosphorescence.

It is a challenge to acquire, realize, and comprehend highly emissive phosphorescent molecules. Herein, we report that, using persulfurated benzene compounds as models, phosphorescence can be strongly enhanced through the modification of molecular conformation and crystal growth conditions. By varying the peripheral groups in these compounds, we were able to control their molecular conformation and crystal growth mode, leading to one- (1D), two- (2D), and three-dimensional (3D) crystal morphologies. Two kinds of typical molecular conformations were separately obtained in these crystals through substituent group control or the solvent effect. Importantly, a symmetrical 3,3-conformer exhibits that a planar central benzene ring prefers a 3D-type crystal growth mode, demonstrating high phosphorescence efficiency. Such outcome is attributed to the strong crystal protection effect of the 3D crystal and the bright global minimum (GM) boat-like T1 state of the symmetrical 3,3-conformer. The conformation studies further reveal small deformation of the inner benzene ring in both singlet and triplet states. The GM boat-like T1 state is indicated by theoretical calculations, which is far away from the conical intersection (CI) point between the S0 and T1 potential energy surfaces. Meanwhile, the small energy gap between S1 and T1 states and the considerable spin-orbit coupling matrix elements allow an efficient population of the T1 state. Combined with the crystal protection and conformation effect, the 3,3-conformer crystal shows high phosphorescence efficiency. The unsymmetrical 2,4-conformer conformation with the twisted central benzene ring leads to 1D or 2D crystal growth mode, which has a weak crystal protection effect. In addition, the unsymmetrical conformation has a dark GM T1 state that is very close to the T1-S0 CI point, implying an efficient nonradiative T1-S0 quenching. Thus, weak phosphorescence was observed from the unsymmetrical conformation. This study provides an insight for the development of highly emissive phosphorescent materials.

A TD-DFT study of the excited dissociative electronic states of the DNA nucleobases bound to Li+

In this work, the first and second dissociative potential curves of adenineLi+ (ADLi+), guanineLi+ (GUALi+), cytosineLi+(CYTLi+), and thymineLi+ (THYLi+) complexes, related to the dissociation of their LiO and LiN bonds, have been calculated in the gas phase and water, separately. For this purpose, the fifteen excited potential curves, in order of increasing energy, were calculated for each complex and the dissociative potential curves were distinguished from them considering the conical intersection points. The time-dependent density functional theory (TD-DFT) method employing the M06-2X functional was used for the calculations. It was observed that the electron transfer from the DNA base to the Li+ took place during the dissociation of complexes in the gas phase. The electrostatic field of water blocked this charge transfer and led to the excited DNA base and Li+ in its ground state. The vertical excitation energy for the desorption of the Li fragment as a neutral and cation species from the DNA bases was determined. The effect of the interaction site of Li+ on the dissociative potential curves was also investigated.

Non-adiabatic Dynamics Mechanism in Excited State of Novel UV Protective Sunscreen in Rice: Conical Intersection Promotes Internal Conversion

Ferulic acid and its derivative γ-oryzanol are common in Rice. They have the same molecular skeleton with some sunscreens that used commonly, but there were no reports on them as rice UV protection. In this work, UV absorption and fluorescence emission spectrum are performed to measure ferulic acid and γ-oryzanol effect of fighting with ultraviolet irradiation. We demonstrated that both ferulic acid and γ-oryzanol have good absorption intensity at UVA, UVB and UVC regions, with superior photostability. Furthermore, the optimized molecular conformation and potential energy surfaces (PES) in ground and excited states are obtained by using the time-dependent density functional theory (TD-DFT) method. From the calculation results, it can conclude that their S1 states decay to the S0 state via internal conversion (IC) process at the S1/S0 conical intersection (CI) point of PES followed by trans–cis photoisomerization. For the first time, we elucidated the mechanism of UV protection for ferulic acid and γ-oryzanol as UV protection in rice from our excited state non-adiabatic dynamics.

Synthesis, photophysical characterization, CASSCF/CASPT2 calculations and CT-DNA interaction study of amino and azido benzazole analogues

This work describes the synthesis and photophysical investigation of amino and azido benzazoles. The amino derivatives were obtained by condensation reaction between ortho-substituted anilines and p-aminobenzoic in polyphosphoric acid. The respective azides were synthesized by reaction of diazonium salts from the previously prepared amines with sodium azide. These compounds present absorption maxima in the UV-A region, nm ascribed to fully spin and symmetry electronic transitions. All compounds presented a main fluorescence emission in the UV-A to the violet region with a relatively large Stokes shift. The latter related to a solvent dependence. The amino derivatives presented higher values to the fluorescence quantum yields in despite of the azido analogues. DFT, TD-DFT and multiconfigurational calculations (SA-CASSCF and MS-CASPT2) were performed in order to investigate the photophysical features of these molecules, mainly on the azide derivatives, where the main interest was the investigation of the intrinsic fluorescence quenching present in these compounds. In this sense, it was observed that the weak fluorescence emission observed in the azide compounds could be related to the dissociative character of the S1 state, which reaches a conical intersection point between S1/S0 states, and through this point, goes back to the ground state by a nonradioactive decay. In addition, the DNA binding assays by UV–Vis absorption and fluorescence emission methodologies indicated that the benzazoles presented strong interaction with CT-DNA, which could be attributed to π-stacking and/or intermolecular hydrogen-bonding. Docking was also performed to better understand the observed interaction.

A strong enhancement in electronic current due to conical-intersection

Due to high degree of nonadiabaticity near the conical intersection point, the electron-vibration entanglement plays a key role in the quantum dynamics. We have studied the current through a molecule with a conical intersection within an electron transport set up considering the source and sink as fermionic reservoirs. A sharp enhancement in current is found which can be identified as a typical feature of conical intersection. This amplification of current is shown to be correlated with the Wigner function and other measures of entanglement. So the typical dynamics due to conical intersection can be probed through an electron transport measurement which stems from an interplay of the persistent and a sensitive type of entanglement present in the system.

Decay dynamics of 6‐azauracil from the light absorbing S2(ππ*) state

AbstractThe initial decay dynamics of 6AU in the S2 state was investigated by using resonance Raman spectroscopy, the time‐dependent wave‐packet theory in a Brownian oscillator model, and complete‐active space self‐consistent field (CASSCF) protocol. The vibrational spectra and the ultraviolet absorption bands were assigned on the basis of the Fourier transform (FT)‐Raman, FT‐infrared measurements, the density‐functional theory computations, and the normal mode analysis. The absorption cross section and the absolute resonance Raman cross sections were simulated simultaneously by using the time‐dependent wave‐packet theory in a Brownian oscillator model. The obtained normal mode displacements of the Franck–Condon active modes were then converted to the short‐time structural dynamics in easy‐to‐visualize internal coordinates. The roles of two pathways via the S2 → S1 internal conversion and the S2 → T3 intersystem crossing were evaluated through the comparison between the short‐time structural dynamics and the CASSCF/CASTP2 calculated structural changes between FC and S2S1 or between FC and S2T3. The results indicate that the structural dynamics in the Franck–Condon region of the S2 state is mostly toward the S2/S1 conical intersection, which supports the conclusion that the S2 → S1 internal conversion dominants the initial decay pathway of 6AU as revealed by the broadband fs TA spectroscopy, whereas the barrierless S2 → T3 intersystem‐crossing process is negligible owing to weak spin‐orbital coupling and unfavorable subsequent T3 → T2 → T1 decay. The reaction coordinates towards the planar S2(ππ*)/S1(nπ*) and severely distorted S2(ππ*)/S0 conical intersection points are proposed respectively, and the solvent effect on the initial decay mechanisms of 6AU, uracil, and thymine is clarified.

Practical approach for beryllium atomic clusters: TD-DFT potential energy surfaces from equilibrium to dissociation for excited states of 2s → 2p

To shed light on the spectroscopic energy-smearing mechanism of the recently developed technique for multi-element analysis (e.g., forensic tests on artworks), which is called plume laser-induced fluorescence, practically computer simulations need to be accurate and fast enough for generating wide-range excited-state potential energy surfaces (PESs) from equilibrium to dissociation of large (non-equilibrated) atomic clusters. Currently, all the very high-level post-Hartree–Fock theories (e.g., coupled-cluster theory) are computationally too expensive for this purpose (e.g., taking at least ~ 23 years). After considering the extensive applications of time-dependent density-functional theory (TD-DFT) in computing the optical properties of many-body systems, we wonder how TD-DFT performs in the wide-range-PES generations because no such TD-DFT application is found by us in the literature (perhaps due to its insufficient static/non-dynamical correlation energy). In this work, we carried out TD-DFT calculations on beryllium atomic clusters from Be1 to Be50 (in contrast to open-shell H2 or Li2 system, we think the individual closed-shell Be systems at the dissociation limit could help TD-DFT to describe the static/non-dynamical correlation. For example, it is usually considered that Be2 has zero non-dynamical correlation energy in the literature) with and without Tamm–Dancoff approximation (TDA). Electronic excited-state properties (e.g., PES, equilibrium position, dissociation energy, fork intersection) associated with 2s → 2p are systematically investigated at a total of 48 levels of TD-DFT. Our calculations are thoroughly benchmarked against experimental results and (very) high-level theoretical values. In short, we find that for accurate simulations, it is necessary to use diffuse basis sets and the TDA approximation. TD-DFT with the small basis set 3-21+G* took ~ 2 min to finish a single-point excitation energy calculation on a linear Be50 (a toy model), while the large basis set 6-311+G(2df,2p) took 30 min. By contrast, a couple-cluster theory EOM-CCSD with 6-311+G(2df,2p) took 2.5 h to do the same but merely for a smaller linear Be10. In general, we suggest that TD-DFT:TDA with 3-21+G* should be practically fast and accurate enough for emulating our desired wide-range excited-state PESs of large Be atomic clusters (including conical intersection points of close energies) in the future studies. Nevertheless, benchmarking work on (much) larger sizes of Be clusters will always be more desirable whenever its computational costs at very high level of theories becomes more tractable.

A comprehensive benchmark of the XMS-CASPT2 method for the photochemistry of a retinal chromophore model

ABSTRACTThe performance of the extended multi-state (XMS)-complete active space second-order perturbation theory (CASPT2) method has been assessed for the benchmark of a truncated retinal model, the penta-2,4-dieniminium cation (PSB3). This benchmark presents a challenge for multireference electronic structure methods because the wave function character is changing considerably. The assessment comprises ground and excited state pathways of the isomerisation, including transition states and conical intersection (CI) points. It also includes circular paths centred around different CIs, and 2D potential energy scans located in the branching planes. In this work, we compare the performance of the previous formulations of CASPT2, the single-state and the multi-state, with the recently developed XMS-CASPT2. Besides, we have also tested two variants of internal contraction in XMS-CASPT2, namely, the single-state single reference (SS-SR) and multi-state multireference (MS-MR) schemes. In our study, we find that XMS-CASPT2 corrects the artefacts and discontinuities present in other CASPT2 variants. The investigation of a circular loop and 2D potential energy surfaces around the surface crossing point shows that XMS-CASPT2 exhibits a smooth topology at the CI with the correct degeneracy. It also agrees better with the reference method MRCISD+Q in regions of the potential energy surfaces further away from CIs. Another observation is the close agreement between the results from the SS-SR contraction scheme and the more demanding MS-MR scheme.

Introducing time-dependent molecular fields: a new derivation of the wave equations

This article is part of a series of articles trying to establish the concept Molecular Field. The theory that induced us to introduce this novel concept is based on the Born-Huang expansion as applied to the Schroedinger equation that describes the interaction of a molecular system with an external electric field. Assuming the molecular system is made up of two coupled adiabatic states the theory leads from a single spatial Curl Equation, two space-time Curl equations and one single space-time Divergent equation to a pair of decoupled Wave Equations usually encountered within the theory of fields. In the present study the Wave Equations are derived for an external field having two features: (a) its intensity is high enough; (b) its duration is short enough. For this situation the study reveals that the just described interaction creates two fields that coexist within a molecule: one is a novel vectorial field formed via the interaction of the external field with the Born-Huang non-adiabatic coupling terms (NACT) and the other is an ordinary, scalar, electric field essentially identical to the original external field. Part of the present study is devoted to the visualization of the outcomes via two intersecting Jahn-Teller cones which contain NACTs that become singular at their intersection point, also known as the point of Conical Intersection. This description is reminiscent of a metaphoric cosmic Black-Hole which swallows one type of an electric field and creates a new type. Finally, the fact that eventually we are facing a kind of a cosmic situation may bring us to speculate that singular NACTs are a result of cosmic phenomena. Thus, if indeed this singularity is somehow connected to reality then, like other singularities in physics, it is formed at (or immediately after) the Big Bang (and because of that, eventually the ability to form molecules).