Static Correlation Research Articles

Resources Integration Theory and Gray Correlation Analysis: A Study for Evaluating China's Agri-food Systems Supply Capacity

China's agri-food systems face the challenge of ensuring food and grain security for a large population with limited resources. This paper constructs a resources integration theory, which classifies agricultural resources into six types and measures their correlation with food and grain supply capacity using grey correlation analysis. The results show that, during 2002-2020, among the factor resources, the highest correlation with food and grain was technology; among the related industry resources, the highest correlation with food was rural roads, and with grain was agricultural machinery; among the demand resources, the highest correlation was domestic market; among the six types of resources, the highest correlation was government resources; and the static correlation evaluation indices of agricultural resources with food and grain supply capacity were 0.8312 and 0.8090, respectively, indicating a compare match. Based on the results, this paper argues that the Chinese agri-food system is matched with agricultural resources, but still needs to be improved to achieve a high match. Opportunity resources, foreign investment, and international markets are disadvantageous resources because China has insufficient ability to stably utilize foreign resources. China’s proposal of a "big food view" is conducive to reducing dependence on factor resources, especially cultivated land and water resources.

Toward Benchmark-Quality Ab Initio Predictions for 3d Transition Metal Electrocatalysts: A Comparison of CCSD(T) and ph-AFQMC.

Generating accurate ab initio ionization energies for transition metal complexes is an important step toward the accurate computational description of their electrocatalytic reactions. Benchmark-quality data is required for testing existing theoretical methods and developing new ones but is complicated to obtain for many transition metal compounds due to the potential presence of both strong dynamical and static electron correlation. In this regime, it is questionable whether the so-called gold standard, coupled cluster with singles, doubles, and perturbative triples (CCSD(T)), provides the desired level of accuracy─roughly 1-3 kcal/mol. In this work, we compiled a test set of 28 3d metal-containing molecules relevant to homogeneous electrocatalysis (termed 3dTMV) and computed their vertical ionization energies (ionization potentials) with CCSD(T) and phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC) in the def2-SVP basis set. A substantial effort has been made to converge away the phaseless bias in the ph-AFQMC reference values. We assess a wide variety of multireference diagnostics and find that spin-symmetry breaking of the CCSD wave function and the PBE0 density functional correlate well with our analysis of multiconfigurational wave functions. We propose quantitative criteria based on symmetry breaking to delineate correlation regimes inside of which appropriately performed CCSD(T) can produce mean absolute deviations from the ph-AFQMC reference values of roughly 2 kcal/mol or less and outside of which CCSD(T) is expected to fail. We also present a preliminary assessment of density functional theory (DFT) functionals on the 3dTMV set.

Post-CCSD(T) corrections to bond distances and vibrational frequencies: the power of Λ

The importance of post-CCSD(T) corrections as high as CCSDTQ56 for ground-state spectroscopic constants ( D e , ω e , ω e x e , and α e ) has been surveyed for a sample of two dozen mostly heavy-atom diatomics spanning a broad range of static correlation strength. While CCSD(T) is known to be an unusually felicitous ‘Pauling point’ between accuracy and computational cost, performance leaves something to be desired for molecules with strong static correlation. We find CCSDT(Q) Λ to be the next ‘sweet spot’ up, of comparable or superior quality to the much more expensive CCSDTQ. A similar comparison applies to CCSDTQ(5) Λ vs. CCSDTQ5, while CCSDTQ5(6) Λ is essentially indistinguishable from CCSDTQ56. A composite of CCSD(T)-X2C/ACV5Z-X2C with [CCSDT(Q) Λ – CCSD(T)]/cc-pVTZ or even cc-pVDZ basis sets appears highly effective for computational vibrational spectroscopy. Unlike CCSDT(Q) which breaks down for the ozone vibrational frequencies, CCSDT(Q) Λ handles them gracefully.

Correlation between Quality of Life, Depression, and Cognitive Function of the Elderly Living in Gyeongsangnam-do

Objectives: The purpose of this study is to find out the correlation between the quality of life, depression, and cognitive function of the elderly, and to identify the causal relationship on each variable to provide basic data for elderly activities and related research and scientific basic data necessary to improve elderly welfare. Methods: A total of 821 samples were used for data analysis by selecting male and female seniors aged 65 or older as the population who participated in the Gyeongnam Niyagara customized service project program in 2022. Pearson correlation analysis was conducted to find out the correlation, and regression analysis was conducted to verify the relevance. Results: First, as a result of analyzing the correlation of all variables, there was a significant negative correlation between quality of life and cognitive function (<i>p</i> = -0.104), there was also a significant negative correlation between quality of life and depression (<i>p</i> = -0.288). There was a significant static correlation between age and cognitive function (<i>p</i> = 0.070), and a significant static correlation between cognitive function and depression (<i>p</i> = 0.180). Second, as a result of conducting a regression analysis to confirm the causal relationship on each variable, the quality of life (F = 35.12, <i>p</i> = 0.000), cognitive function (F = 15.13, <i>p</i> = 0.000), depression (F = 47.00, <i>p</i> = 0.000) showed statistical significance, and age (F = 1.43, <i>p</i> = 0.233) showed no statistical significance. Conclusions: Based on the results of this study, it is expected that various policies and follow-up studies will be conducted to improve the quality of life, relieve depression, and cognitive function health of the elderly.

Quantum Chemical Studies on Possible Molecular Devices Based on Electric Field-Induced Intramolecular Charge Transfer.

We report quantum chemical studies on possible molecular devices working based on electric field-induced intramolecular charge transfer (EFIMCT). In the case of donor-acceptor (DA)-type molecular systems, intramolecular charge transfer (IMCT) can be induced by applying the external electric field to molecular systems along the charge transport direction, providing a possible switching mechanism which does not depend upon the electron-phonon coupling effect and is different from the negative differential resistance mechanism observed in the well-known NO2-substituted phenylene ethynylene oligomers. When the EFIMCT proceeds, the molecular systems have strong static electron correlation effects, where the standard nonequilibrium Green's function-density functional theory (DFT) approach cannot be applied to the molecular junction. As a first step toward practical switching devices, we do quantum chemical studies on the EFIMCT in such molecular systems as an isolated molecule, instead of using the electrode-junction-electrode open quantum system model. A prototype molecule P1 is designed as a tentative candidate molecule where the EFIMCT can proceed. The complete active space self-consistent field (CASSCF) molecular orbital calculations on P1 indicate that the EFIMCT can proceed at the external electric field intensity of 0.003 au, corresponding to about 2.25 V bias voltage. This calculated result strongly suggests that the development of this type of switching devices working at practically low bias voltage is feasible if the molecular system is properly designed. Broken symmetry unrestricted Hartree-Fock and spin-polarized Kohn-Sham DFT calculations also qualitatively reproduce the CASSCF results on P1, to some extent, indicating that these approaches can be employed for rough estimations on the EFIMCT such as the first screening of a large quantity of candidate molecules for this type of molecular devices. The possibility of molecular memory devices based on the EFIMCT is also discussed by analyzing the ground and excited potential energy surface model. Remaining challenges to develop practical molecular devices are discussed.

Soft pinning: Experimental validation of static correlations in supercooled molecular glass-forming liquids.

Enormous enhancement in the viscosity of a liquid near its glass transition is a hallmark of glass transition. Within a class of theoretical frameworks, it is connected to growing many-body static correlations near the transition, often called "amorphous ordering." At the same time, some theories do not invoke the existence of such a static length scale in the problem. Thus, proving the existence and possible estimation of the static length scales of amorphous order in different glass-forming liquids is very important to validate or falsify the predictions of these theories and unravel the true physics of glass formation. Experiments on molecular glass-forming liquids become pivotal in this scenario as the viscosity grows several folds (), and simulations or colloidal glass experiments fail to access these required long-time scales. Here we design an experiment to extract the static length scales in molecular liquids using dilute amounts of another large molecule as a pinning site. Results from dielectric relaxation experiments on supercooled Glycerol with different pinning concentrations of Sorbitol and Glucose, as well as the simulations on a few model glass-forming liquids with pinning sites, indicate the versatility of the proposed method, opening possible new avenues to study the physics of glass transition in other molecular liquids.

Dynamic Correlation on the Adaptive Sampling Configuration Interaction (ASCI) Reference Function: ASCI-DSRG-MRPT2.

A balanced description of static and dynamic electron correlations is at the heart of quantum chemical methods. To obtain accurate results in strongly correlated systems using wave-function-based methods, a large active space is necessary to ensure correct descriptions of static correlations. Correcting the results for dynamic correlations is also necessary. In this work, we present implementations of second-order perturbation theory for dynamic correlations based on the adaptive sampling configuration interaction self-consistent field (ASCI-SCF) method. In particular, we implemented spin-free driven similarity renormalization group second-order multireference perturbation theory (DSRG-MRPT2). The extrapolation of the ASCI + PT2 energy based on the relaxed Hamiltonian in DSRG-MRPT2 gives a reasonable approximation of DSRG-MRPT2 based on CASSCF. We demonstrate the application of the ASCI-DSRG-MRPT2 method in evaluations of the spin-state energy gaps in iron porphyrins, polyacenes, and periacenes along with the reaction energies of methane oxidation by FeO+ and electrocyclic ring formation in cethrene.

Extending Conceptual Density Functional Theory toward First-Order Reduced Density Matrices: An Open Subsystems Viewpoint on the Fukui Matrix.

As a matrix extension of the Fukui function, a reactivity descriptor grounded within Conceptual Density Functional Theory, the Fukui matrix extends Frontier Molecular Orbital Theory to correlated regimes with its eigendecomposition in Fukui occupations and Fukui naturals. Despite successful applications, the questions remain as to whether replacing a quantity derived from a purely density-based framework by its matrix extension is theoretically well-founded and what chemical information is contained in the corresponding eigendecomposition. In this study, we show that the matrix extension of the Fukui function is only well-defined if one also generalizes the external potential to become nonlocal, leading to the introduction of Conceptual First-Order Reduced Density Matrix Functional Theory. By interpreting the Anderson impurity model from an interacting open subsystem perspective, we show how Fukui occupations and Fukui naturals reflect the influence of an increasing (static) correlation and which characteristic patterns we should expect within a molecular context. This study represents a step in generalizing Conceptual Density Functional Theory beyond its density-based perspective.

중국 패션디자인 전공 대학생의 주도적 성격이 진로결정자기효능감을 매개로 진로준비행동에 미치는 영향

Objectives This study analyzed the mediating effect of career decision self-efficacy in the influence of initiative personality on career preparation behavior of Chinese college students majoring in fashion design. Methods Initiative personality, career decision self-efficacy, and career preparation behavior were measured for 539 college students majoring in fashion design who are attending universities in Guangxi and Hunan provinces, China, and career decision self-efficacy in the path leading from initiative personality to career preparation behavior. Results As a result of the analysis, there were significant differences in career preparation behavior according to general characteristics according to grade and major grades, and statistically significant static correlations were confirmed between all variables. The direct effect of the initiative personality of Chinese college students majoring in fashion design on career preparation behavior was not confirmed. Conclusions The initiative personality has no direct effect on career preparation behavior, but has an indirect effect through career decision self-efficacy. Therefore, it is necessary to enable college students to carry out specific and practical career preparation behaviors through the formation of career decision self-efficacy based on the leading personality.

신임경찰관의 북한이탈주민 인식태도 및 수용성 확대 방안에 관한 인식 연구

The purpose of this study is to present policy suggestions on desirable attitudes toward North Korean defectors through empirical research on the level of familiarity and interest in North Korean defectors, image of North Korea, and image-shaping influence media for new police officers trained at the National Central Police Academy. In order to conduct empirical research, a survey was conducted on 300 adult men and women in their 20s and older who were educated at the National Central Police Academy through the self-evaluation method. From October 1 to October 10, 2021, 300 people responded to a randomized sampling survey with a response rate of 100%, using 300 surveys and analyzed using the IBM SPSS program. As a result of the analysis, the frequency of contact with North Korean defectors in terms of demographic characteristics showed a static correlation with affinity for North Korean defectors, and a talisman correlation with the image of North Korea. Attitudinal traits showed a statistically significant correlation between the three variables of friendliness, interest, and image with North Korean defectors. As for the affinity for North Korean defectors, it can be seen that the more frequent contact there is, the higher the affinity for North Korean defectors. In terms of interest in North Korean defectors, women were more interested in North Korean defectors than men, a statistically significant difference. The image of North Korea showed an inappropriate correlation with the frequency of contact with North Korean defectors. In other words, the more North Korean defectors meet, the more negative images of North Korea accumulate. When we checked the media that influenced the formation of North Korea's image, the media (TV and media media) accounted for more than half of the media (56.0%), followed by the Internet (including SNS) and education. This study seeks to make the following policy recommendations. First, it is the gradual resolution of the “South-South conflict” in Korean society. Second, strengthen multicultural education and publicity activities for the people. Third, the development of various policies. Fourth, comprehensive network construction. Fifth, it is necessary to limit the spread of negative images of North Korean defectors in the mass media. Sixth, strengthen training for new police officers.

Populist governments, judicial independence, and public trust in the courts

ABSTRACT Can governments make courts politically compliant without undermining public confidence in the judicial system? Many studies show a positive relationship between judicial independence and citizens’ trust in courts. However, most of them have shown static cross-sectional correlations rather than actual effects of court curbing on trust. Factors such as citizens’ level of education and political preferences may also play a role in moderating reactions to court curbing. We analyse how assaults on judicial independence by populist governments in Turkey, Hungary, and Poland affected judicial trust, using a difference-in-differences approach to Eurobarometer data. While we find evidence that court curbing has an adverse effect on judicial trust, this effect is much clearer among citizens who are ideologically distant from their governments. These findings coincide with experimental evidence indicating how citizens tolerate democratic backsliding, suggesting that, for many, trust in the judicial system can subsist even when courts are made politically subservient.

Valence and Core Photoelectron Spectra of Aqueous I3- from Multi-Reference Quantum Chemistry.

The I3- molecule is known to undergo substantial structural reorganization upon solvation by a protic solvent, e.g., water. However, the details of this process are still controversially discussed in the literature. In the present study, we combined experimental and theoretical efforts to disentangle this controversy. The valence (5p), N4,5 (4d), and M4,5 (3d) edge photoelectron spectra were measured in an aqueous solution and computed using high-level multi-reference methods. Our previous publication mainly focused on obtaining reliable experimental evidence, whereas in the present article, we focused primarily on theoretical aspects. The complex electronic structure of I3- requires the inclusion of both static and dynamic correlation, e.g., via the multi-configurational perturbation theory treatment. However, the resulting photoelectron spectra appear to be very sensitive to problems with variational stability and intruder states. We attempted to obtain artifact-free spectra, allowing for a more reliable interpretation of experiments. Finally, we concluded that the 3d Photoelectron Spectrum (PES) is particularly informative, evidencing an almost linear structure with a smaller degree of bond asymmetry than previously reported.

Core-Excited States and X-ray Absorption Spectra from Multireference Algebraic Diagrammatic Construction Theory.

We report the development and benchmark of multireference algebraic diagrammatic construction theory (MR-ADC) for the simulations of core-excited states and X-ray absorption spectra (XAS). Our work features an implementation that incorporates core-valence separation into the strict and extended second-order MR-ADC approximations (MR-ADC(2) and MR-ADC(2)-X), providing efficient access to high-energy excited states without including inner-shell orbitals in the active space. Benchmark results on a set of small molecules indicate that at equilibrium geometries, the accuracy of MR-ADC is similar to that of single-reference ADC theory when static correlation effects are not important. In this case, MR-ADC(2)-X performs similarly to single- and multireference coupled cluster methods in reproducing the experimental XAS peak spacings. We demonstrate the potential of MR-ADC for chemical systems with multiconfigurational electronic structure by calculating the K-edge XAS spectrum of the ozone molecule with a multireference character in its ground electronic state and the dissociation curve of core-excited molecular nitrogen. For ozone, the MR-ADC results agree well with the data from experimental and previous multireference studies of ozone XAS, in contrast to the results of single-reference methods, which underestimate relative peak energies and intensities. The MR-ADC methods also predict the correct shape of the core-excited nitrogen potential energy curve, and are in good agreement with accurate calculations using driven similarity renormalization group approaches. These findings suggest that MR-ADC(2) and MR-ADC(2)-X are promising methods for the XAS simulations of multireference systems and pave the way for their efficient computer implementation and applications.

Role of Charge Ordering in the Dynamics of Cluster Formation in Associated Liquids.

Liquids are archetypes of disordered systems, yet liquids of polar molecules are locally more ordered than nonpolar molecules, due to the Coulomb interaction based charge ordering phenomenon. Hydrogen bonded liquids, such as water or alcohols, for example, represent a special type of polar liquids, in that they form labile clustered local structures. For water, in particular, hydrogen bonding and the related local tetrahedrality, play an important role in the various attempts to understand this liquid. However, labile structures imply dynamics, and it is not clear how it affects the understanding of this type of liquids from purely static point of view. Herein, we propose to reconsider hydrogen bonding as a charge ordering process. This concept allows us to demonstrate the insufficiency of the analysis of the microscopic structure based solely on static pair correlation functions, and the need for dynamical correlation functions, both in real and reciprocal space. The subsequent analysis allows to recover several aspects of our understanding of hydrogen bonded liquids, but from the charge order perspective. For water, it confirms the jump rotation picture found recently, and it allows to rationalize the contradicting pictures that arise when following the interpretations based on hydrogen bonding. For alcohols, it allows to understand the dynamical origin of the scattering prepeak, which does not exist for water, despite the fact that both these liquids have very similar hydroxyl group chain clusters. The concept of charge ordering complemented by the analysis of dynamical correlation functions appear as a promising way to understand microheterogeneity in complex liquids and mixtures from kinetics point of view.

보육교사의 교사효능감과 교사역할수행의 관계에서 전문성 인식의 매개효과

Objectives The purpose of this study is to examine the relationship between childcare teachers' teacher efficacy, teachers' professional perception, and role performance, and to examine the mediating effect of professional perception on teacher efficacy and role performance.
 Methods The study subjects used data collected from 212 nursery teachers from daycare centers located in Gyeonggi, Seoul. The structural equation model was analyzed to identify the structural relationships between the major variables, and the bootstrapping method was used to determine the mediating effect.
 Results First, the results of this study showed a significant static correlation between teacher efficacy, professionalism recognition, and teacher role performance of childcare teachers. Second, it was discovered that childcare teachers' perceptions of expertise had a direct impact on their ability to perform their roles. Third, there was a partial mediating effect of professionalism recognition in the relationship between teacher efficacy and role performance of childcare teachers.
 Conclusions It is important to raise teachers' awareness of efficacy and professionalism in order to increase the level of role performance of childcare teachers. Based on the results of this study, basic data were provided for the development of national policies and professional education programs be of significance to.

Correlation balance for describing carbenes: An NOF study

Carbenes are a remarkable type of molecules because of the two electrons that might be paired or unpaired, providing a singlet or a triplet state, respectively. The preference for one of these states can be measured by the singlet-triplet energy gap; however, theoretical prediction is challenging when static correlation arises, and an adequate balance with dynamic correlation is required to achieve correct predictions. Piris Natural Orbital Functionals (PNOFs) have been used before to deal with other static correlation problems, but they have suffered from lack of dynamic correlation, which has been solved by coupling PNOF7 with many-body perturbation theory. Recently, the development of a Global Natural Orbital Functional (GNOF) has been proposed with the aim of including dynamic correlation without the need to couple with perturbation theory, thus becoming a promising alternative to study challenging chemical problems. In this work, we applied the PNOF family of functionals to compute the adiabatic singlet-triplet energy gaps of a set of simple carbenes and compared them with those computed with coupled-cluster methods and experimental values when available. We have found that the GNOF achieves promising results due to an intrinsic balance of static and dynamic correlation. In this regard, the GNOF presents errors that are lower than those of PNOF7, comparable to those of NOF-c-MP2, and is capable of predicting the tendency of substituent effects, proving to be suitable for further application to predict general singlet-triplet energy gaps.

Unraveling effects of electron correlation in two-dimensional FenGeTe2 (n = 3, 4, 5) by dynamical mean field theory

The FenGeTe2 systems are recently discovered two-dimensional van-der-Waals materials, exhibiting magnetism at room temperature. The sub-systems belonging to FenGeTe2 class are special because they show site-dependent magnetic behavior. We focus on the critical evaluation of magnetic properties and electron correlation effects in FenGeTe2 (n = 3, 4, 5) (FGT) systems performing first-principles calculations. Three different ab initio approaches have been used primarily, viz., (i) standard density functional theory (GGA), (ii) incorporating static electron correlation (GGA + U) and (iii) inclusion of dynamic electron correlation effect (GGA + DMFT). Our results show that GGA + DMFT is the more accurate technique to correctly reproduce the magnetic interactions, experimentally observed transition temperatures and electronic properties. The inaccurate values of magnetic moments, exchange interactions obtained from GGA + U make this method inapplicable for the FGT family. Correct determination of magnetic properties for this class of materials is important since they are promising candidates for spin transport and spintronic applications at room temperature.

Stationary time correlations for fermions after a quench in the presence of an impurity

We consider the quench dynamics of non-interacting fermions in one dimension in the presence of a finite-size impurity at the origin. This impurity is characterized by general momentum-dependent reflection and transmission coefficients which are changed from to at time t = 0. The initial state is at equilibrium with such that the system is cut in two independent halves with , , respectively, to the right and to the left of the impurity. We obtain the exact large time limit of the multi-time correlations. These correlations become time translationally invariant, and are non-zero in two different regimes: i) for where the system reaches a non-equilibrium steady state (NESS), ii) for , i.e., the ray regime. For a repulsive impurity these correlations are independent of , , while in the presence of bound states they oscillate and memory effects persist. We show that these nontrivial relaxational properties can be retrieved in a simple manner from the large time behaviour of the single particle wave functions.

초등학교 교사가 지각한 학생의 문제행동과 소진과의 관계

Objectives This study explored the relationship between elementary school teachers' perception of student problem behavior, teacher mindfulness, and burnout, and verified whether mindfulness had a moderating effect on the relationship between student problem behavior and burnout.
 Methods To this end, a survey of elementary school teachers located in Jeju-si was conducted from October 15 to October 30, 2020, and 165 data were used for analysis. In order to confirm the mean and standard deviation of major variables, descriptive statistical analysis and correlation analysis were performed to verify the relationship between variables. Hierarchical regression analysis was conducted to verify the moderating effect of teacher mindfulness and its sub-factors, which are regulatory variables.
 Results The main results of this study are as follows. There is a significant static correlation between teacher-perceived problem behavior and burnout, and the higher the teacher's perceived problem behavior, the higher the possibility of experiencing burnout. Second, it was found that mindfulness has a negative correlation with teacher burnout, so that the more mindfulness teachers practice, the lower the burnout phenomenon. Third, as a result of examining the moderating effect of teacher mindfulness in the relationship between students' perception of problem behavior and burnout, there was no moderating effect that could alleviate teacher's burnout.
 Conclusions Based on the research results, suggestions to prevent burnout of elementary school teachers and follow-up studies to explore moderating variables that can alleviate burnout caused by students' problem behaviors were suggested.

Effect of magnetic order on longitudinal Tomonaga-Luttinger liquid spin dynamics in weakly coupled spin- 12 chains

The quantum many-body interactions in one-dimensional spin-$\frac{1}{2}$ systems are subject to Tomonaga-Luttinger liquid (TLL) physics, which predict an array of multiparticle excitations that form continua in momentum-energy space. Here we use inelastic neutron spectroscopy to study the TLL spin dynamics in ${\mathrm{SrCo}}_{2}{\mathrm{V}}_{2}{\mathrm{O}}_{8}$, a compound which contains weakly coupled spin-$\frac{1}{2}$ chains of Co atoms, at 0.05 K and in a longitudinal magnetic field up to 9.0 T. The measurements were performed above 3.9 T, where the ground-state N\'eel antiferromagnetic (AFM) order is completely suppressed and the multiparticle excitations are exclusively of the TLL type. In this region and below 7.0 T, the longitudinal TLL mode---psinon/antipsinon (P/AP)---is unexpectedly well described by a damped harmonic oscillator (DHO) while approaching the zone center defining the static spin-spin correlations. A non-DHO-type, continuumlike signal is seen at higher fields, but deviations from the ideal one-dimensional TLL still remain. This change in the P/AP mode coincides with the phase transition between the longitudinal spin density wave (LSDW) and transverse AFM order. Inside the LSDW state, the DHO-type P/AP spectral weight increases and the linewidth broadens as the magnetic order parameter decreases. These results reveal the impact of three-dimensional magnetic order on the TLL spin dynamics; they call for beyond-mean-field treatment for the interchain exchange interactions.