Orbital Components Research Articles

Adopting the empirical CODE orbit model to Galileo satellites

In 2012 the Center for Orbit Determination in Europe (CODE) joined the Multi-GNSS-EXtension project (MGEX) of the International GNSS Service (IGS). Since the end of 2013 the CODE MGEX contributions were based on combined solutions of five already established and emerging GNSS: GPS, GLONASS, Galileo, BeiDou and QZSS. This undertaking was made possible thanks to the continuous development of new models and approaches and their introduction in our processing schemes in order to ensure the delivery of products of the highest quality.The European Galileo system with a total number of active satellites reaching the level of a nominal constellation is currently complete. Because of their relatively high area-to-mass ratio the Galileo spacecraft are more sensitive to non-gravitational forces than other GNSS satellites. The introduction of the extended empirical CODE orbit model (ECOM2) to the CODE MGEX solutions in early 2015 resulted in a significant improvement of the Galileo products. The use of the Galileo satellites metadata, which were made publicly available in the course of 2016 and 2017, has further enhanced the quality of the produced solutions. However, they still show significant degradations during eclipse seasons in particular for long-arc solutions (e.g., over three days), which are similarly observed in solutions of other IGS MGEX analysis centers to different extents. In particular this is reflected in elevated orbit misclosures, deterioration of the estimated satellite clock corrections and excessive satellite laser ranging (SLR) residuals during these periods. Since the ECOM2 parameters are designed to absorb the effect of solar radiation pressure, they are switched off during eclipses. Hence, there is no empirical force parameter left that can absorb any unmodelled perturbations (e.g., due to thermal radiation (TR)) during an eclipse period.In this study we take advantage of the satellites’ metadata to address the Galileo TR-induced accelerations and, therefore, to advance our orbit model further. By adjusting existing and introducing additional empirical parameters, as well as adopting a priori accelerations to account for unmodelled perturbations we achieve a significant improvement of our solutions. In particular, the use of a once-per-revolution sine term in the ECOM E3 direction (satellite-Sun), activation of the constant term in the ECOM E2 direction (along the solar panels) during the Earth’s shadow transitions as well as the use of a priori acceleration in the body-fixed +X direction substantially improve our solutions. The introduced modifications to the orbit model allow for an efficient adjustment of satellite velocity along the orbit that is necessary due to the apparent presence of unmodelled thermal radiation. The refinements lead to a substantial reduction of orbit misclosures and improvement of the radial orbital component accuracy during eclipse seasons up to 14% w.r.t. the solutions using ECOM2.

Very Heavy Flavored Dibaryons.

We explore the possibility of very heavy dibaryons with three charm quarks and three beauty quarks, bbbccc, using a constituent model which should lead to the correct solution in the limit of hadrons made of heavy quarks. The six-body problem is treated rigorously, in particular taking into account the orbital, color, and spin mixed-symmetry components of the wave function. Unlike a recent claim based on lattice QCD, no bound state is found below the lowest dissociation threshold.

Reoperation in Zygomatico-orbital Trauma: A Review of Patients With Suboptimal Outcomes Following Initial Repair.

Treatment to restore anatomy, function, and aesthetics after trauma should involve as little surgical insult as possible. As such, repeated procedures may suggest failed initial management. To date, no predictive factors for failure of primary surgery have been identified. The aim of this review was to identify factors affecting the requirement for reoperation following treatment of zygomatico-orbital injuries. A retrospective review of patients undergoing surgery for zygomatico-orbital fractures between 2011 and 2019 in a single UK major trauma center was undertaken. All operative notes and imaging were reviewed independently by 2 authors to classify the fracture patterns for both zygomatic and orbital components of the injury. For all cases, the mode of preoperative imaging the grade of operating surgeon, materials used for fixation, and the surgical approaches were recorded. Coding data identified 432 patients who underwent surgery for zygomatico-orbital fractures. In total, 116 cases were treated with closed reduction and 316 with open reduction and internal fixation; 20 cases required reoperation. There were no significant differences identified between cases requiring reoperation and those who did not. A need for repeated surgery is rare. However, this review identified an increased risk of infection of fixation when an intraoral approach was used and highlights the potential benefits that can be achieved by open reduction and internal fixation when more conservative approaches fail to achieve the desired outcome.

Angular momentum of the electron: One-loop studies

We combine bare perturbation theory with the imaginary time evolution technique to study one-loop radiative corrections to various components of angular momentum of the electron. Our investigations are based on the canonical decomposition of angular momentum, where spin and orbital components, associated with fermionic and electromagnetic degrees of freedom, are individually approached. We use for this purpose quantum electrodynamics in the general covariant gauge and develop a formalism, based on the repeated use of the Sochocki-Plemelj formula, for proper enforcement of the imaginary time limit. It is then shown that careful implementation of imaginary time evolutions is crucial for getting a correct result for total angular momentum of the electron in the bare perturbative expansion. We also analyze applicability of the Pauli-Villars regularization to our problem, developing a variant of this technique based on modifications of studied observables by subtraction of their ghost operator counterparts. It is then shown that such an approach leads to the consistent regularization of all angular momenta that we compute.

Chemical trend of a Cu impurity in Zn chalcogenides

Cu is usually considered as an effective dopant to introduce shallow acceptors in Zn chalcogenides because it is on the left-hand side of Zn in the Periodic Table. Here, using first-principles calculations based on the hybrid functional with spin polarization, we show that contrary to the common expectation, Cu substituting Zn ($\mathrm{C}{\mathrm{u}}_{\mathrm{Zn}}$) in bulk Zn chalcogenides actually generates rather deep acceptor levels in ZnO, ZnS, and ZnSe, i.e., 2.91, 1.03, and 0.53 eV above the valence-band maximum (VBM), respectively, except in ZnTe (0.13 eV). More interestingly, the absolute Cu impurity energy level does not follow the variation of the VBM, decreasing from ZnTe to ZnSe to ZnS to ZnO, instead, it is the highest in ZnO. The abnormal behavior of $\mathrm{C}{\mathrm{u}}_{\mathrm{Zn}}$ in ZnO is attributed to the fact that, due to the very low O $2p$-orbital energy, the $\mathrm{C}{\mathrm{u}}_{\mathrm{Zn}}$ defect wave function has dominantly localized the Cu $3d$-orbital component, whereas in other Zn chalcogenides, anion $p$ states are dominant. The localized Cu $3d$ state leads to the enhanced exchange energy that elevates the acceptor level, which explains why the Cu impurity level is abnormally deep in ZnO. This finding provides insight in designing shallow acceptor levels in II--VI semiconductors.

Masses of tetraquark states in the hidden charm sector above D − D⁎ threshold

In the diquark-antidiquark composition, we study the masses of hidden charm tetraquark systems (cqc¯q¯, csc¯s¯ and csc¯q¯) using a linear confinement potential. In this study, we have factorized the four body system into three subsequent two body systems. To remove degeneracy in the S and P wave masses of mesons and tetraquark states, the spin-spin, spin orbit and tensor components of the confined one gluon exchange interactions are employed. In this attempt, we have been able to assign the ψ(4230) as pure cqc¯q¯ tetraquark state. ψ(4360) and ψ(4390) as pure csc¯q¯ tetraquark states. According to our analysis ψ(4260) is found to be an admixture of two P11cqc¯q¯ tetraquark states having mass 4259 MeV. Additionally, we have been able to predict the radiative decay width Γ(ψ→J/ψγ), leptonic decay width Γe+e− and hadronic decays of 1−− tetraquark states. The status of X(3872) and Zcs are also identified as compact tetraquark states. Additionally, we have been able to predict the radiative decay width Γ(ψ→J/ψγ), leptonic decay width Γe+e− and hadronic decays of 1−− tetraquark states.

Theory of the orbital moment in a superconductor

The chiral p-wave superconducting state is comprised of spin triplet Cooper pairs carrying a finite orbital angular momentum. For the case of a periodic lattice, calculating the net magnetisation arising from this orbital component presents a challenge as the circulation operator $\hat{\bf{r}} \times \hat{\bf{p}}$ is not well defined in the Bloch representation. This difficulty has been overcome in the normal state, for which a modern theory is firmly established. Here, we derive the extension of this normal state approach, generating a theory which is valid for a general superconducting state, and go on to perform model calculations for a chiral p-wave state in Sr$_2$RuO$_4$. The results suggest that the magnitude of the elusive edge current in Sr$_2$RuO$_4$ is finite, but lies below experimental resolution. This provides a possible solution to the long-standing controversy concerning the gap symmetry of the superconducting state in this material.

First-principles calculation of spin and orbital contributions to magnetically ordered moments in Sr2IrO4

We show how an accurate first-principles treatment of the canted-anti-ferromagnetic ground state of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$, a prototypical $5d$ correlated spin-orbit coupled material, can be obtained without invoking any free parameters, such as the Hubbard $U$ or tuning the spin-orbit coupling strength. Our theoretically predicted iridium magnetic moment of $0.250{\ensuremath{\mu}}_{B}$, canted by $12.{6}^{\ensuremath{\circ}}$ off the $a$ axis, is in accord with experimental results. By resolving the magnetic moments into their spin and orbital components, we show that our theoretically obtained variation of the magnetic scattering amplitude $\ensuremath{\langle}{M}_{m}\ensuremath{\rangle}$ as a function of the polarization angle is consistent with recent nonresonant magnetic x-ray scattering measurements. The computed value of the band gap (55 meV) is also in line with the corresponding experimental values. A comparison of the band structure to that of the cuprates suggests the presence of incommensurate charge-density wave phases in ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.

Astronomical pacing of Late Cretaceous third- and second-order sea-level sequences in the Foz do Amazonas Basin

Because of their relatively reduced tectonic influence, post-rift sedimentary successions have a propensity to preserve climatically-driven cyclicity over long durations. Here we present an integrated cyclostratigraphic and sequence stratigraphic study of the post-rift Limoeiro sedimentary Formation (Fm) of the Foz do Amazonas Basin (offshore Brazil), which spans the entire Late Cretaceous epoch (almost 35 Myr long). The principal goal of the present study is to decipher very long (multi-Myr) sedimentary cyclicities and their potential origin(s) in order to delineate the main controlling factors of post-rift sediment sequences and packages. We used gamma-ray (GR) well-log data for cyclostratigarphy, and seismic data for sequence stratigraphy. Time-series analysis of GR data shows a rich series of Milankovitch frequency bands. In particular, long-period cyclicities (405 kyr, 2.4 Myr, 4.7 Myr and 9.5 Myr) are detected with high fidelity. Seismic and sequence stratigraphic interpretation shows a striking sea-level (SL) depositional sequence order, matching the 4.7 Myr orbital cyclicity inferred from cyclostratigraphy. Longer SL sequences interpreted in previous studies from the Limoeiro Fm closely match the 9.5 Myr GR related orbital cycles. Thus, we infer that the post-rift Limoeiro Fm was deposited continuously under astronomical forcing over the Late Cretaceous epoch, resulting in an extraordinary record of direct base- and sea-level responses to Milankovitch climatic forcing, including longer (multi-Myr) periodicities. The 4.7 Myr orbital component is recorded for the first time in SL sedimentary proxies, thus allowing here to update SL hierarchical orders. We suggest that third-order, and second-order and suborders SL sequences were most likely paced by long-period astronomical cycles (2.4 Myr eccentricity, and 4.7 and 9.5 Myr orbital cycles, respectively. • An integrated cyclo-seismic stratigraphy detects 2.4, 4.7 and 9.5 Myr orbital cycles. • 2.4, 4.7 and 9.5 Myr orbital cycles match third and second-order sea-level sequences. • The 4.7 Myr orbital cycle is highlighted for the first time in sea-level record.

Soft X-Ray and Cathodoluminescence Examination of a Tanzanian Graphite Deposit.

Hyperspectral soft X-ray emission (SXE) and cathodoluminescence (CL) spectrometry have been used to investigate a carbonaceous-rich geological deposit to understand the crystallinity and morphology of the carbon and the associated quartz. Panchromatic CL maps show both the growth of the quartz and the evidence of recrystallization. A fitted CL map reveals the distribution of Ti4+ within the grains and shows subtle growth zoning, together with radiation halos from 238U decay. The sensitivity of the SXE spectrometer to carbon, together with the anisotropic X-ray emission from highly orientated pyrolytic graphite, has enabled the C Kα peak shape to be used to measure the crystal orientation of individual graphite regions. Mapping has revealed that most grains are predominantly of a single orientation, and a number of graphite grains have been investigated to demonstrate the application of this new SXE technique. A peak fitting approach to analyzing the SXE spectra was developed to project the C Kα 2pz and 2p(x+y) orbital components of the graphite. The shape of these two end-member components is comparable to those produced by electron density of states calculations. The angular sensitivity of the SXE spectrometer has been shown to be comparable to that of electron backscatter diffraction.

Photocatalytic decomposition of methylene blue by Cr/TiO2 composite coatings

ABSTRACT In this research, the Cr/TiO2 composite coatings were formed in Na2HPO4 + NaOH + Cr2O3 by micro-arc oxidation (MAO) technology with different ratios of anodic and cathodic currents. Surface morphology results showed that the pancake-like structures on the coating surface decreased with the ratio decreased. XRD results showed the TiO2:Cr3+ coatings are composed of anatase and rutile phase and the anatase content first increased and then decreased. XPS results indicated that Ti2p spin–orbit components of the Cr/TiO2 composite coatings are shifted towards higher binding energy, compared with the pure TiO2 coating, suggesting that some of the Cr3+ ions are incorporated into TiO2 lattice. The photocatalytic experiment results showed that the photocatalytic activity of Cr/TiO2 MAO coatings can be greatly enhanced with a moderate amount of Cr3+.

Binary–binary scattering in the secular limit

ABSTRACT Binary–binary interactions are important in a number of astrophysical contexts including dense stellar systems such as globular clusters. Although less frequent than binary–single encounters, binary–binary interactions lead to a much richer range of possibilities such as the formation of stable triple systems. Here, we focus on the regime of distant binary–binary encounters, i.e. two binaries approaching each other on an unbound orbit with a periapsis distance Q much larger than the internal binary separations. This ‘secular’ regime gives rise to changes in the orbital eccentricities and orientations, which we study using analytic considerations and numerical integrations. We show that ‘direct’ interactions between the three orbits only occur starting at a high expansion order of the Hamiltonian (hexadecupole order), and that the backreaction of the outer orbit on the inner two orbits at lower expansion orders is weak. Therefore, to good approximation, one can obtain the changes of each orbit by using previously known analytic results for binary–single interactions, and replacing the mass of the third body with the total mass of the companion binary. Nevertheless, we find some dependence of the ‘binarity’ of the companion binary, and derive explicit analytic expressions for the secular changes that are consistent with numerical integrations. In particular, the eccentricity and inclination changes of orbit 1 due to orbit 2 scale as ϵSA, 1(a2/Q)2[m3m4/(m3 + m4)2], where ϵSA, 1 is the approximate quadrupole-order change, and a2 and (m3, m4) are the companion binary orbital semimajor axis and component masses, respectively. Our results are implemented in several python scripts that are freely available.

Hyperostosing sphenoid wing meningiomas: surgical outcomes and strategy for bone resection and multidisciplinary orbital reconstruction.

Hyperostosing sphenoid wing meningiomas cause bony hyperostosis that may extend into the orbit, resulting in proptosis, restriction of extraocular movements, and/or compressive optic neuropathy. The extent of bony removal necessary and the optimal reconstruction strategy to prevent enophthalmos is debated. Herein, the authors present their surgical outcomes and reconstruction results. This is a retrospective review of 54 consecutive patients undergoing resection of sphenoid wing meningiomas associated with bony hyperostosis. The majority of cases were operated on by the senior author. Extent of tumor resection, volumetric bone resection, radiographic exophthalmos index, complications, and recurrence were analyzed. The median age of the cohort was 52.1 years, with women comprising 83% of patients. Proptosis was a presenting symptom in 74%, and 52% had decreased visual acuity. The WHO grade was I (85%) or II (15%). The median follow-up was 2.6 years. On volumetric analysis, a median 86% of hyperostotic bone was resected. Gross-total resection of the intracranial tumor was achieved in 43% and the orbital tumor in 27%, and of all intracranial and orbital components in 20%. Orbital reconstruction was performed in 96% of patients. Postoperative vision was stable or improved in 98% of patients and diplopia improved in 89%. Postoperative complications occurred in 44% of patients, and 26% of patients underwent additional surgery for complication management. The most frequent complications were medical complications and extraocular movement deficits. The median preoperative exophthalmos index was 1.26, which improved to 1.12 immediately postoperatively and to 1.09 at the 6-month follow-up (p < 0.001). Postoperatively, 18 patients (33%) underwent adjuvant radiotherapy after subtotal resection. Tumors recurred/progressed in 12 patients (22%). Resection of hyperostosing sphenoid wing meningiomas, particularly achieving gross-total resection of hyperostotic bone with a good aesthetic result, is challenging and associated with notable medical and ocular morbidity. Recurrence rates in this series are higher than previously reported. Nevertheless, the authors were able to attain improvement in proptosis and visual symptoms in the majority of patients by using a multidisciplinary approach.

Theoretical calculation of total electron-impact ionization cross section of C6F12O

C6F12O can be used in gas-insulated equipment due to its excellent insulation properties. The purpose of this paper is to calculate the total electron-impact ionization cross section to evaluate the dielectric strength of the molecule using the Deutsch–Märk formula. First, according to the calculation method of quantum chemistry, the structure of the molecule is optimized. Three different methods, such as Mulliken population analysis, C-squared population analysis, and natural atomic orbital (NAO), are used to calculate the molecular orbital components, and then the molecular collision cross section is obtained. The influence of different weighting factors on the calculation results is analyzed. The validity of the proposed method is verified by the calculation results of H2O, C3H6O, and C5F10O. The results show that the calculation value with the NAO method is closer to the experimental results, which provides a reference for the calculation and analysis of the collision cross section of C6F12O. The calculation results in this paper can provide basic data for further calculation of the dielectric strength of C6F12O.

Coherent photons with angular momentum in a helical afterburner

We analytically examine several important characteristics of coherent radiation emitted from a relativistic electron beam in a helical undulator. The goal is to highlight specific attributes relevant to the production of bright x-rays with angular momentum in a free-electron laser (FEL) afterburner. The far-field complex electric field distribution is derived, and for small forward emission angles, it is confirmed that the spin and orbital components of angular momentum in the radiation are separable, additive, and aligned with the handedness of the electron motion. The coherent energy radiated at harmonics $h$ from a bunched electron beam is then calculated, and used to evaluate the emission energy from a FEL afterburner configuration. Results show that an afterburner undulator with ${N}_{u}\ensuremath{\gg}1$ periods and of sufficient strength will produce harmonic pulses with energy $\ensuremath{\sim}1/{N}_{u}^{h\ensuremath{-}1}$ times that of the fundamental, depending on the Fresnel number $N=k{\ensuremath{\sigma}}_{x}^{2}/{L}_{u}$ of the radiating electron beam.

Modelling and analysis of a cracked rotor: a review of the literature and its implications

Timely detection of fatigue cracks is necessary to avoid catastrophic failure of rotating machines which can lead to economical losses and accidental risk. This paper presents an exhaustive literature survey on theoretical and experimental vibration analysis of the rotating shaft in the presence of crack. Various non-destructive methods adopted by several researchers for crack detection in rotating machinery have been discussed. The vibration-based crack detection methods such as vibration-based diagnostics methods and vibration-based signal processing techniques have been broadly categorized along with their advantages and disadvantages. In general, various methodologies such as breathing mechanism, finite-element method, Hilbert–Huang transform, artificial intelligence techniques, wavelet transform and wavelet finite-element transform have been applied to investigate the presence of crack in the rotating shaft. The parameters such as natural frequencies, $$1{\times }$$, $$2{\times }$$ and $$3{\times }$$ harmonic components of dynamic response, critical speeds and whirl orbits have been significantly influenced due to the presence of crack in the rotating shaft. Several studies have been carried out to study variations in these parameters. Still, there is a need of more reliable and accurate modelling approach to detect variations in these parameters. In this paper, an attempt has been made to deliver all the modelling approaches implemented by the various researchers to detect crack within the rotating shaft. The modelling approaches are categorized based on the methodologies adopted by the various researchers to detect crack. Moreover, the critical observations made from the proposed modelling approaches are summarized and presented.

Experimental study of intruder components in light neutron-rich nuclei via single-nucleon transfer reaction

With the development of radioactive beam facilities, studies concerning the shell evolution of unstable nuclei have recently gained prominence. Intruder components, particularly s-wave intrusion, in the low-lying states of light neutron-rich nuclei near N=8 are of importance in the study of shell evolution. The use of single-nucleon transfer reactions in inverse kinematics has been a sensitive tool that can be used to quantitatively investigate the single-particle orbital component of selectively populated states. The spin-parity, spectroscopic factor (or single-particle strength), and effective single-particle energy can all be extracted from such reactions. These observables are often useful to explain the nature of shell evolution, and to constrain, check, and test the parameters used in nuclear structure models. In this article, the experimental studies of the intruder components in low-lying states of neutron-rich nuclei of He, Li, Be, B, and C isotopes using various single-nucleon transfer reactions are reviewed. The focus is laid on the precise determination of the intruder s-wave strength in low-lying states.

Solitary Fibrous Tumors of the Lacrimal Drainage System With Variable Orbital and Sinonasal Extensions: Combined External and Endoscopic Surgical Approach.

To report techniques and outcomes of a combined external and endoscopic surgical approach in the management of solitary fibrous tumors of the lacrimal drainage system with variable orbital and sinonasal extensions. Biopsy proven cases of solitary fibrous tumors of the lacrimal drainage system involving the lacrimal sac and the nasolacrimal ducts with an orbital, sinonasal, or intranasal extension were studied. Parameters assessed include patient demographics, clinical presentation and course, operative techniques, complications, postoperative adjuvant therapies and outcomes. The technique is described in 3 patients. Two patients had massive orbital extension and one had gross sinonasal extension. Nasolacrimal duct extension was involved in all the patients with intranasal extension in 2 patients. External approach was used to access the lacrimal sac and the orbital components while the endoscopic approach was used to assess the orbital clearance and manage the sinonasal extension and the nasolacrimal duct excision up to the inferior meatus. Following complete excision, additional biopsies were performed from the adjacent bones and sinonasal tissues. A detailed histopathology with immunohistochemistry is essential for not only the diagnosis but also to assess the margin clearance. There were no major postoperative complications. All the patients were advised for postoperative adjuvant external beam radiotherapy. At the last follow-up, none of the patients had any clinical or endoscopic evidence of a recurrence. A combined external and endoscopic approach en-block excision is most suitable management modality for solitary fibrous tumors involving the lacrimal sac and the nasolacrimal ducts with orbital and sinonasal extension.

Interconversion of orbital and spin angular momenta of light beams in the sum-frequency generation process from the surface of the isotropic chiral medium

We study the interaction between spin and orbital components of the angular momentum of electromagnetic waves in the sum-frequency generation process on a surface of the nonlinear isotropic chiral medium within undepleted pump approximation. Both bulk and near-surface responses of the medium are taken into account. Classical and quantum explanations of particular features of three-wave mixing on the surface of a nonlinear medium are presented.

Coupling of two curved polyaromatic radical-anions: stabilization of dimers by counterions.

In this study, a comprehensive theoretical investigation of both kinetic and thermodynamic stabilities was performed for dimeric dianionic systems (C20H10)22- and (C28H14)22-, neutralized by two alkali metal cations. The influence of the counterions was of primary interest. The impact of the additional/spectator ligand(s) was elucidated by considering adducts with four molecules of diglyme or two molecules of 18-crown-6 ether. Importantly, both types of systems - in the form of contact-ion pair (CIP) and solvent-separated ion pair (SSIP) - were considered. The SSIP set was augmented by the adduct, in which the dimeric dianionic species were neutralized with purely organic cations N(CH3)4+ and P(CH3)4+. Detailed analysis of the bonding revealed that the presence of the counterions made these systems thermodynamically stable. This finding is in sharp contrast with results obtained for isolated (PAH)22- systems, which were previously found to be thermodynamically unstable, but kinetically persistent. The introduction of the alkali metal cations to the system significantly increases the ionic term (ΔEelstat), whereas the repulsive ΔEPauli one was found to be substantially reduced. Considering that the orbital component (ΔEorb) exhibited only a moderate decrease and the preparation energy (ΔEprep) showed no changes, the above-mentioned changes in ΔEelstat and ΔEPauli provided a clear explanation for the increase of the thermodynamic stability of the target species. Importantly, a clear correlation between the size of the alkali metal cation and stability of the target dimeric product was established. Thermodynamic stability of the system rises with a decrease in the size of M+ due to enlargement of the ΔEorb. Evaluated energy barriers (as spin-crossing points between singlet and triplet energy surfaces) were found to be equal to +15.85 kcal mol-1 and +18.5 kcal mol-1 for [(Cs+)2{(C20H10)22-}] and [(Cs+)2{(C28H14)22-}], respectively, which is substantially higher than those calculated for isolated (PAH)22- systems (+10.00 kcal mol-1 for (C20H10)22- and +12.35 kcal mol-1 for (C28H14)22-). Thus, this study identified the presence of counterions as the key factor, which have a dramatic influence on the thermodynamic and kinetic stabilities of the aimed dianionic dimeric systems, which are formed by two curved polyaromatic monoanion-radicals.