IF 1.8

Atoms Pub Date : 2023-06-15 DOI: 10.3390/atoms11060099

A. Kuzmenko, V. Gauzshtein, E. Darwish, A. Fix, M. Kuzin, M. Levchuk, A. Loginov, D. Nikolenko, I. Rachek, Y. Shestakov, D. Toporkov, A. Yurchenko, B. Vasilishin, S. Zevakov

引用次数: 1

Pulse Cycle Dependent Nondipole Effects in Above-Threshold Ionization 阈值以上电离中脉冲周期相关的非偶极子效应

IF 1.8

Atoms Pub Date : 2023-06-12 DOI: 10.3390/atoms11060097

Danish Furekh Dar, S. Fritzsche

引用次数: 0

Structure and Bonding Patterns in C5H4 Isomers: Pyramidane, Planar Tetracoordinate Carbon, and Spiro Molecules C5H4异构体的结构和键合模式：吡喃、平面四配位碳和螺环分子

IF 1.8

Atoms Pub Date : 2023-06-10 DOI: 10.3390/atoms11060096

Sayon Satpati, T. Roy, Sandip Giri, A. Anoop, Venkatesan S. Thimmakondu, S. Ghosal

{"title":"Structure and Bonding Patterns in C5H4 Isomers: Pyramidane, Planar Tetracoordinate Carbon, and Spiro Molecules","authors":"Sayon Satpati, T. Roy, Sandip Giri, A. Anoop, Venkatesan S. Thimmakondu, S. Ghosal","doi":"10.3390/atoms11060096","DOIUrl":"https://doi.org/10.3390/atoms11060096","url":null,"abstract":"We have theoretically investigated nine unusual isomers of the molecular formula C5H4 using coupled cluster (CC) and density functional theory (DFT) methods. These molecules possess non-classical structures consisting of two pyramidanes, three planar tetracoordinate carbon (ptC), and four spiro types of isomers. Both the pyramidanes (tetracyclo-[2.1.0.01,3.02,5]pentane; py-1 and tricyclo-[2.1.0.02,5]pentan-3-ylidene; py-2) are minima on the potential energy surface (PES) of C5H4. Among the three isomers containing ptC, (SP4)-spiro [2.2]pent-1-yne (ptC-2) is a minimum, whereas isomer, (SP4)-spiro [2.2]pent-1,4-diene (ptC-1) is a fourth-order saddle point, and (SP4)-sprio[2.2]pent-1,4-diylidene (ptC-3) is a transition state. The corresponding spiro isomers spiro[2.2]pent-1,4-diene (spiro-1), sprio[2.2]pent-1,4-diylidene (spiro-3) and spiro[2.2]pent-4-en-1-ylidene (spiro-4) are local minima, except spiro[2.2]pent-1-yne (spiro-2), which is a second-order saddle point. All relative energies are calculated with respect to the global minimum (pent-1,3-diyne; 1) at the CCSD(T)/cc-pVTZ level of theory. Quantum chemical calculations have been performed to analyze the bonding and topological configurations for all these nine isomers at the B3LYP/6-311+G(d,p) level of theory for a better understanding of their corresponding electronic structures. ptC-2 was found to be thermodynamically more stable than its corresponding spiro counterpart (spiro-2) and possesses a high dipole moment (μ = 4.64 D). The stability of the ptC structures with their higher spin states has been discussed.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47074064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Improved Line Intensity Analysis of Neutral Helium by Incorporating the Reabsorption Processes in a Helium Collisional-Radiative Model 结合氦碰撞-辐射模型中重吸收过程的中性氦谱线强度改进分析

IF 1.8

Atoms Pub Date : 2023-06-08 DOI: 10.3390/atoms11060094

K. Lin, M. Goto, H. Akatsuka

{"title":"Improved Line Intensity Analysis of Neutral Helium by Incorporating the Reabsorption Processes in a Helium Collisional-Radiative Model","authors":"K. Lin, M. Goto, H. Akatsuka","doi":"10.3390/atoms11060094","DOIUrl":"https://doi.org/10.3390/atoms11060094","url":null,"abstract":"In this study, eight emission lines in the visible wavelength range of neutral helium were used to diagnose the electron density and temperature of the Large Helical Device (LHD) helium plasma instead of the conventional three-line method. The collisional-radiative (CR) model for low-pressure helium plasma was revised to include the optical escape factors for spontaneous transition from the n1P states to the ground state so that the influence of the absorption effect under optically thick conditions could be considered. The developed algorithm was based on fitting the number densities of eight excited states obtained using optical emission spectroscopy (OES). The electron density, electron temperature, ground-state density, and optical escape factors were selected as the fitting parameters. The objective function was set as the summation of the residual errors between the number densities measured in the experiment and those calculated using the revised model. A regularization term was introduced for the optical escape factor and optimized through bias and variance analyses. The results show that the agreement between the number density calculated by the algorithm and its counterpart measured in the experiment was generally improved compared to the method using three lines.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49151681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Editorial of the Special Issue “General Relativistic Atomic Structure Program—GRASP” 《广义相对论原子结构程序-把握》特刊社论

IF 1.8

Atoms Pub Date : 2023-06-06 DOI: 10.3390/atoms11060093

J. Bieroń, C. Fischer, P. Jönsson

引用次数: 0

Modification of Vibrational Parameters of a CO2 Molecule by a Laser Field: Impact on Tunnel Ionization 激光场对CO2分子振动参数的改变:对隧道电离的影响

IF 1.8

Atoms Pub Date : 2023-06-05 DOI: 10.3390/atoms11060092

A. S. Kornev, V. Chernov

引用次数: 0

High-Order Above-Threshold Ionization Using a Bi-Elliptic Orthogonal Two-Color Laser Field with Optimal Field Parameters 具有最佳场参数的双椭圆正交双色激光场的高阶阈值电离