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Optimizing computational parameters for Nuclear Electronic Orbital Density Functional Theory: A Benchmark Study on Proton Affinities

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JOURNAL OF computational CHEMISTRY 2025年第8期46卷 e70082页

作者： Khan, Raza Ullah Tonner-Zech, Ralf Wilhelm Ostwald Inst Phys & Theoret Chem Leipzig Germany

This study benchmarks the nuclear electronic orbital density functional theory (NEO-DFT) method for a set of molecules that is larger than in previous studies. The focus is on proton affinity predictions to assess the influences of computational parameters. NEO-DFT incorporates nuclear quantum effects for protons involved in protonation processes. Using a test set of 72 molecules with experimental proton affinities as reference, we evaluated various exchange-correlation functionals, finding that B3LYP-based functionals deliver the most accurate results. Among the tested functionals, CAM-B3LYP performs the best with an MAD value of 6.2 kJ/mol with respect to experimental data. In NEO-DFT, electron-proton correlation (epc) functionals were assessed, with LDA-type epc17-2 yielding comparable results to the GGA-type epc19 functional. Compared to traditional DFT (MAD value of 31.6 kJ/mol), which treats nuclei classically, NEO-DFT provides enhanced accuracy for proton affinities when electron-proton correlation is included. Regarding basis sets, the def2-QZVP electronic basis set achieved the highest accuracy with an MAD value of 5.0 kJ/mol, though at a higher computational cost compared to def2-TZVP and def2-SVP, while nuclear basis sets showed minimal impact on proton affinity accuracy and no consistent trend. Overall, this study demonstrates NEO-DFT's efficacy in addressing nuclear quantum effects for proton affinity predictions, providing guidance on optimal parameter selection for future NEO-DFT applications.

关键词： benchmarking computational parameters light nuclei NEO-DFT nuclear quantum effects nuclear-electronic orbital proton affinity

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High-strain-rate mechanical constitutive modeling with computational parameters

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INTERNATIONAL JOURNAL OF PLASTICITY 2025年 189卷

作者： Lei, Mingyu Huang, Jie Li, Yanxian Zhang, Liqiang Yang, Guochun Wen, Bin Yanshan Univ Ctr Extreme Deformat Res State Key Lab Metastable Mat Sci & Technol Qinhuangdao 066004 Peoples R China Yanshan Univ Clean Nano Energy Ctr State Key Lab Metastable Mat Sci & Technol Qinhuangdao 066004 Peoples R China Yanshan Univ Sch Sci Hebei Key Lab Microstruct Mat Phys Qinhuangdao 066004 Peoples R China

Mechanical constitutive relationships characterize the strain response of materials under external loading, laying the foundation for optimizing material performance and guiding engineering design. However, existing modeling methods for mechanical constitutive relationships, especially for high strain rate (HSR) loading, often rely on fitted experimental data and fail to comprehensively capture the underlying physical mechanisms. In this work, we propose a mechanical constitutive modeling with computational parameters (MCMCP) method suitable for HSR loading conditions, which establishes a quantitative link between the microstructure of materials and their macroscopic mechanical properties by fully integrating fundamental physical principles. This method couples the thermally activated dislocation unpinning mechanism with the phonon drag effect to accurately describe dislocation velocity and the influence of strain rate on plastic behavior. Additionally, a multi-mechanism coordinated strength-solving framework is introduced. It predicts the slip-twinning transition and quantitatively evaluates the contributions of various strengthening mechanisms. By incorporating microstructural evolution information, the material's flow stress-strain response can also be predicted. Validation against simulations of pure metals and alloys confirms the effectiveness of the proposed method. This work not only enhances the understanding of micro-scale physical mechanisms for mechanical behavior but also provides a practical tool for predicting the mechanical properties under HSR loading.

关键词： High strain rate loading Mechanical constitutive modeling computational parameters Microstructural evolution Strengthening mechanisms

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An investigation on the wake flow of a generic ship using IDDES: The effect of computational parameters

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OCEAN ENGINEERING 2023年第1期271卷

作者： Zhang, Jie Gidado, Faisal Adamu, Abdulmalik Guo, Zhanhao Gao, Guangjun Cent South Univ Sch Traff & Transportat Engn Key Lab Traff Safety Track Minist Educ Changsha 410075 Peoples R China Cent South Univ Joint Int Res Lab Key Technol Rail Traff Safety Changsha 410075 Peoples R China Natl & Local Joint Engn Res Ctr Safety Technol Rai Changsha 410075 Peoples R China Hong Kong Polytech Univ Dept Civil & Environm Engn Hung Hom Kowloon Peoples R China

The study of the ship airwake is critical as it explores the effect of unsteady wake flow on helicopter operations. This paper studied the near-wake flow topology of a generic ship at Re = 8 x 104 to assess the capability of a hybrid RANS/LES (Reynolds-averaged Navier-Stokes/large-eddy simulation) approach, known as IDDES (improved delayed detached-eddy simulation). The impact of computational parameters, including the mesh grid, residual level, time-step size, momentum discretization scheme and transient formulation, on the wake flow was investigated. The numerical results were validated by using the previous experimental data and LES results. The results show that except of the mesh resolution all other computational parameters varied in the current study do not have significant effect on the global drag forces, but showing large differences on the prediction of the local wake flow structures. This point has not been evidently reported in the previous work. The finer grid resolution is sufficient to produce an accurate qualitative and quantitative prediction of the flow structures, while using a poor grid resolution (coarse mesh) leads to inaccurate prediction of the flow topology. The recommended parameters for the time-step size (7.5 x 10-5s) and residual level (1 x 10-4) provide sufficient accuracy of wake predictions, showing good agreement with reference studies. For the convective term of the momentum equation in IDDES, the bounded central differencing scheme is proposed for its discretization, while the bounded second -order implicit is proposed to be adopted as the transient formulation.

关键词： Generic ship computational parameters Flow asymmetry Wake flow

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Evaluation of computational and physical parameters influencing CFD simulations of pollutant dispersion in building arrays

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BUILDING AND ENVIRONMENT 2018年 137卷 90-107页

作者： Dai, Yuwei Mak, Cheuk Ming Ai, Zhengtao Hang, Jian Hong Kong Polytech Univ Dept Bldg Serv Engn Kowloon Hong Kong Peoples R China Tech Univ Denmark Dept Civil Engn Int Ctr Indoor Environm & Energy Lyngby Denmark Sun Yat Sen Univ Sch Environm Sci & Engn Dept Atmospher Sci Guangzhou Guangdong Peoples R China

Many CFD studies have investigated the influence of computational parameters on the predicted concentration distribution of pollutants around isolated buildings, but such studies for building arrays are still lacking. This study systematically evaluated the influence of four computational and two physical parameters on pollutant dispersion in building arrays, including turbulence models, grid resolution, discretization of time step size Delta t, length of sampling period, aspect ratio of the arrays, and release rate of tracer gas. Throughout these evaluations, a set of published wind tunnel experimental data was used to validate the CFD models. For concentration simulations , the Large Eddy Simulation (LES) model gave the most accurate results but still had limitations in areas near the source, whereas the Detached Eddy Simulation (DES) and the Reynolds Averaged Navier-Strokes (BANS) RNG k - epsilon models underperformed in some areas. The results of the LES and DES simulations varied with changes in Delta t* and sampling length until Delta t* was less than 0.24 and the sampling length was higher than 2400 Delta t* for LES and 1200 Delta t* for DES. A larger aspect ratio did not necessarily result in a higher concentration field than a smaller ratio. An increase in the tracer gas release rate did not change the general dispersion characteristics, but it still affected the concentration distribution in the areas near the source and resulted in a larger polluted area. The findings of this study are intended to contribute to improvements in the quality of CFD simulations of pollutant dispersion in building arrays.

关键词： CFD simulation Pollutant dispersion Building arrays computational parameters Sensitivity test

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Applying the parametric learning tactic along with the Welch signal processing technique in designing a depression recognition system using electroencephalogram

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BIOMEDICAL SIGNAL PROCESSING AND CONTROL 2025年 108卷

作者： Changizi, Melika Rashidi, Saeid Zolfagharzadeh-Kermani, Mahdi Islamic Azad Univ Fac Med Sci & Technol Sci & Res Branch Tehran Iran

Major depression is a common psychological disorder that, if left untreated, can negatively affect a person's cognitive function and lifestyle quality. The design of machine learning-based recognition systems using electroencephalogram (EEG) data enables the ability to identify mental disorders by increasing understanding of brain functional mechanisms. In this study, Welch's technique was used to analyze EEG signals and subsequently identify biomarkers related to depression. Hence, based on the reductionism approach, the processing unit of the system was interpreted as a combination of the computational parameters of the Welch technique including longepoch, short-epoch, and overlap-percentage between epochs along with the measurement parameters of the Welch periodogram including high and low cut frequencies. The reductionism approach means all parameters of the processing unit were adapted not in their links and ratios with each other, but as separate fundamental components concerning the non-linear and non-stationary characteristics of the EEG-signal. Also, the scales for measuring spectral features were developed based on the relativism approach. The relativism approach means extracting spectral features on scales relative to the total power and the theta band. All the parameters and states resulting from these intellectual positions were evaluated using iterative algorithms, and finally, the best performance of the depression recognition system was determined by six frequency indicators related to the spectrum curves of beta, theta, and gamma obtained from five EEG channels. The best results were obtained using the K-Nearest-Neighbor classifier on the design dataset with accuracy of 96.23% and on the generalization dataset with accuracy of 95.40%.

关键词： Biomarker computational parameters Depression Electroencephalogram Measurement parameters Welch Periodogram

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Mono-/multiadsorption of chlorobenzene compounds on biochar: influence of the properties of the chlorobenzene molecules and biochar

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JOURNAL OF SOILS AND SEDIMENTS 2023年第5期23卷 2120-2135页

作者： Yang, Lifei Han, Wenjia Zhao, Wei Gu, Chenggang Xu, Zhihong Jiang, Xin Nanjing Tech Univ Sch Environm Sci & Engn Nanjing 211816 Peoples R China Chinese Acad Sci Inst Soil Sci CAS Key Lab Soil Environm & Pollut Remediat Nanjing 210008 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Griffith Univ Ctr Planetary Hlth & Food Secur Sch Environm & Sci Nathan Qld 4111 Australia

Purpose This study aimed to explore the adsorption behaviors and mechanisms of chlorobenzene compounds (CBs;monochlorobenzene (MCB);1,2-dichlorobenzene (1,2-DCB);pentachlorobenzene (PeCB);and hexachlorobenzene (HCB)) on corn straw-based biochar. Materials and methods The adsorption kinetics and isotherms of the four CBs were investigated in mono- or multi-CB adsorption experiments with the corn straw-based biochar which was pyrolyzed at 500 degrees C and modified with 1 mol/L HCl. Moreover, the surface morphology and porosity of the biochar were characterized. The molecular orbitals, electron cloud distribution, and configuration of the CBs were calculated by the quantum chemical method. The relationships were investigated among the adsorption behaviors and quantum chemical parameters of the CBs as well as the morphology characteristics of the biochar to explore the adsorption mechanisms of the CBs on the biochar. Results and discussion The results showed that in both mono- and multi-adsorbate systems, the adsorption of the CBs was well fitted by the pseudo-second-order, Elovich, and the Freundlich model. The adsorption rates, affinities, and amounts indicated that the biochar preferably absorbed highly chlorinated CBs (PeCB and HCB) over low-chlorinated CBs (MCB and 1,2-DCB). The absolute electronegativity (chi), electrophilicity index (omega), polarizability (alpha), and molecular volume (V-m) followed the increasing order MCB < 1,2-DCB < PeCB < HCB. The values of energy gap of molecular frontier orbitals (Delta E-Gap) and molecular hardness (eta) decreased with increasing halogen number of the CBs. The lower energy gap of molecular frontier orbitals, the less molecular stability, and higher deformability could favor the adsorption of highly chlorinated CBs (PeCB and HCB) on the biochar. Conclusions During the adsorption process of the CBs on the biochar, physisorption and pore filling might be the two associated mechanisms. The biochar with properties (aromatizat

关键词： Adsorption Kinetics Isotherms Chlorobenzenes Biochar computational parameters

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Review of Hydro-Pneumatic Accumulator Models for the Study of the Energy Efficiency of Hydraulic Systems

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ENERGIES 2023年第18期16卷 6472页

作者： Dindorf, Ryszard Takosoglu, Jakub Wos, Piotr Kielce Univ Technol Fac Mechatron & Mech Engn Al Tysiaclec Panstwa Polskiego 7 PL-25314 Kielce Poland

This review article deals with hydro-pneumatic accumulators (HPAs) charged with nitrogen. The focus is on HPA models used in the study of the energy efficiency of hydraulic systems. Hydraulic circuits with HPA are presented along with their various applications for delivering the required volume of fluid, maintaining the required pressure, ensuring safe operation, safety stop, leak compensation, fluid volume change compensation, pulsation damping, and pressure shock absorption. A general regenerative hydraulic system and a general hybrid hydraulic system are also presented. The review focuses primarily on HPA computational, dynamic, and simulation models. Basic HPA calculation parameters and computational models of energy storage and thermodynamic cycle are presented. Various computational and dynamic models of HPA have been defined, such as the thermodynamic model, simulation model, dynamic model, pulsation damper model, and shock pulse damper model. Research projects that have used HPA in industrial hydraulic systems are reviewed, such as those maintaining operating pressure in an industrial 80 MN open-die hydraulic forging press and acting as a shock pulse absorber in the lifting and levelling module of a tracked mobile robotic bricklaying system. The development of energy storage technology in HPA from various sources is now a global challenge.

关键词： hydro-pneumatic accumulators hydraulic systems energy efficiency computational parameters dynamic models

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Affect and Decision Making: Insights and Predictions from computational Models

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TRENDS IN COGNITIVE SCIENCES 2019年第7期23卷 602-614页

作者： Roberts, Ian D. Hutcherson, Cendri A. Univ Toronto Dept Psychol Toronto ON Canada Univ Toronto Rotman Sch Management Dept Mkt Toronto ON Canada

In recent years interest in integrating the affective and decision sciences has skyrocketed. Immense progress has been made, but the complexities of each field, which can multiply when combined, present a significant obstacle. A carefully defined framework for integration is needed. The shift towards computational modeling in decision science provides a powerful basis and a path forward, but one whose synergistic potential will only be fully realized by drawing on the theoretical richness of the affective sciences. Reviewing research using a popular computational model of choice (the drift diffusion model), we discuss how mapping concepts to parameters reduces conceptual ambiguity and reveals novel hypotheses.

关键词： choice computational parameters drift diffusion models emotion

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Aspects of Modern Computing of Medium Voltage Electrical Networks With Neutral Treated by Compensation Coils 16

Aspects of Modern Computing of Medium Voltage Electrical Net...

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16th Conference on Electrical Machines, Drives and Power Systems (ELMA)

作者： Diga, Silvia-Maria Diga, Nicolae Duinea, Adelaida-Mihaela Bratu, Cristian Univ Craiova Fac Elect Engn 107 Decebal Blvd Craiova 200440 Romania Helmke Bur Romania 93 Stefan cel Mare Craiova Romania

ISBN: (纸本)9781728114132

In this paper the authors address the topic of the medium voltage electrical systems with the neutral treated, which consists in the neutral grounding by means of a compensation coil. Thus, the main computational aspects that arise in the case of medium voltage networks having the neutral treated by means of compensating coils are summarized. In this regard, three case studies for 35 kV and 20 kV overhead power lines and respectively 6 kV electric cable lines with neutral compensated by means of compensating coils have been studied. A number of parameters were calculated and the obtained values were interpreted, among which the currents: capacitive earthing;through the compensation coil;earthing;the power absorbed by the coil;unbalance network;uncompensated / compensated network amortization coefficients;the displacement of the neutral point, considering the earthing net or by an arc with a certain resistance value;the power of the special transformer required to create an artificial neutral on the 6 kV side of the electrical system consisting in the cable network, etc. For this purpose, the authors have compiled computational algorithms and also made graphical representations of the various calculated parameters using their own design programs developed in the Mathcad programming environment.

关键词： compensation coils computational algorithms computational parameters medium voltage electrical networks neutral treatment

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Structural shape optimization of free-form surface shell and property of solution search using firefly algorithm

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JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY 2015年第4期29卷 1449-1455页

作者： Tanaka, Natsuki Honma, Toshio Yokosuka, Yohei Kagoshima Univ Dept Architecture & Architectural Engn Kagoshima 8900065 Japan

The computation procedure for structural shape optimization is based on the heuristic optimization procedures, such as swarm intelligence (SI), that use patterns found in self-organizing phenomena observed in nature. Most SI techniques including particle swarm optimization (PSO) and artificial bee colony (ABC), attain a global optimal solution. The firefly algorithm (FA) can attain both a global optimal and local optimal solutions by setting suitable computational parameters. However, the method for setting these parameters is comparatively difficult. In order to simplify the setting of these parameters, we implement a computational scheme where the distance between two fireflies in the design variable space is dimensionless. The effectiveness and the validity of this FA are clarified by showing the diversified solution for a global optimal solution and local optimal solutions using a local search in the structural shape optimization of a free-form surface shell.

关键词： computational parameters Firefly algorithm Local search Global optimal solution and local optimal solutions Single-objective optimization

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