Comprehensive Ab Initio Quantum Computations of CO$_{\rm 2}$-H$_{\rm 2}$ and CO$_{\rm 2}$-He Collisional Properties
Massachusetts Institute of Technology(麻省理工学院);Harvard & Smithsonian(哈佛-史密森尼天体物理中心);Université Paris-Saclay(巴黎萨克雷大学);University of Tunis El Manar(突尼斯曼纳尔大学)
Prajwal Niraula, Laurent Wiesenfeld, Nejmeddine Jaïdane, Julien de Wit, Robert J. Hargreaves, Jeremy Kepner, Deborah Woods, Cooper Loughlin, Iouli E. Gordon
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Submitted. Comments welcome. Data available at zenodo: https:/zenodo.org/records/20435057
We present comprehensive \textsl{ab initio} fully quantum calculations of CO$_{\rm 2}$--H$_{\rm 2}$ and CO$_{\rm 2}$--He collisional properties. Our framework combines CCSD(T) potential-energy-surface calculations with close-coupling dynamical scattering in the \YUMI~framework to derive elastic and inelastic cross sections, rate coefficients, and pressure broadening parameters. We characterize the rotational dependence of the broadening coefficients up to $j=25$ for CO$_{\rm 2}$--H$_{\rm 2}$ and $j=40$ for CO$_{\rm 2}$--He, and their temperature dependence over 40--800 K. We also provide Padé fits as a function of rotational quantum number, enabling extrapolation and integration into spectroscopic databases including HITRAN and HITEMP. The resulting pressure broadening coefficients reproduce available experimental measurements on an absolute scale, without empirical correction factors, and meet the $\sim$10\% precision requirement identified for \textit{JWST}-era exoplanet atmospheric studies. This represents a substantial improvement over previously available parameters, which at higher temperatures ($T>400$ K) can fall outside the desired precision by up to a factor of five. All derivations, computed collisional properties, and database-ready products are provided with this manuscript. Together, these results establish a comprehensive \textsl{ab initio}, parameter-free, fully quantum foundation for CO$_2$ collisional broadening by H$_2$ and He, while demonstrating the transformative potential of the ab-initio approach for next-generation spectroscopic needs across planetary atmospheres, combustion, health sciences, and fusion-plasma diagnostics.
Global potential energy surface for the O2 + N2 interaction. Applications to the collisional, spectroscopic, and thermodynamic properties of the complex
详细描述空气中最丰富的分子之间的相互作用对于理解大气科学中的各种现象非常重要。首次报道了O $_2(^3Σ^-_g)$ + N $_2(^1Σ^+_g)$相互作用的完全{ \em ab initio}全局势能面(PES).它已经得到了利用密度泛函描述的单体[SAPT(DFT)]扩展到处理涉及高自旋开壳复合物的相互作用的微扰理论的自适应。计算的相互作用能与用自旋限制耦合团簇方法在单激发、双激发和非迭代三激发下得到的相互作用能[RCCSD(T)]符合得很好。由{ \em ab initio}数据建立了包含大量相互作用各向异性项的球谐函数展开式。径向展开系数在长范围内与基于最近的单体电性质的{ \em ab initio}计算的解析函数相匹配[M. Bartolomei等人,J. Comp. Chem.,{ \bf 32},279(2011)]。PES测试对第二维里系数$B(T)$数据和积分截面测量与旋转热溢出光束,导致在这两种情况下一个非常好的协议。计算了配合物的第一束缚态,并报道了相互作用配合物的相关光谱特征。还提供了与以前的实验得出的PES的比较。
Hyperfine excitation of N$_2$H$^+$ by H$_2$: Toward a revision of N$_2$H$^+$ abundance in cold molecular clouds
星际云中分子发射光谱的建模需要碰撞速率系数的知识。在通常观察到的物种中,N $_2$ H $^+$是特别感兴趣的,因为它被证明是冷分子云物理条件的良好探针。因此,我们计算了N $_2$ H $^+$(X $^1Σ^+$)的超精细结构分辨激发速率系数H $_2(j=0)$,在冷星际介质中最丰富的碰撞伙伴。计算是基于一个新的势能面,从高度相关的{ \it从头计算}计算。计算了温度从5 K到70 K范围内第一超精细能级之间的态-态速率系数。通过与以前发表的N $_2$ H $^+$ -He速率系数的比较,我们发现了显着的差异,不能由一个简单的缩放关系再现。作为第一个应用程序,我们还进行了辐射转移计算,典型的冷分子云的物理条件。我们发现,模拟线强度显着增加时,使用新的H $_2$率系数,通过与基于He率系数的预测相比。特别是,我们重新审视了在LDN 183核心的N $_2$ H $^+$发射的建模,使用新的碰撞数据,并发现,所有三个密度,气体动力学温度和N $_2$ H $^+$丰度必须进行修改。
Full ab initio atomistic approach for morphology prediction of hetero-integrated crystals: A confrontation with experiments
Univ Rennes, INSA Rennes, CNRS, Institut FOTON – UMR 6082(雷恩大学,雷恩国立应用科学学院,法国国家科学研究中心,FOTON研究所);Centre de Nanosciences et de Nanotechnologies, CNRS, Université Paris-Saclay(纳米科学与工程中心,法国国家科学研究中心,巴黎萨克雷大学)
Density effects in precision laser spectroscopy of exotic helium atoms
Nicolaus Copernicus University in Toruń(托伦哥白尼大学);Radboud University(拉德堡德大学);Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences(保加利亚科学院核研究与核能研究所);University of Warsaw(华沙大学)
Collisional excitation of cyclopentadiene by helium. A complete set of rate coefficients and astrophysical applications
HUN-REN Institute for Nuclear Research(匈牙利科学院核物理研究所);Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251(雷恩大学,法国国家科学研究中心,雷恩物理研究所);Instituto de Física Fundamental (IFF-CSIC)(基础物理研究所)
Ab initio quantum scattering calculations and a new potential energy surface for the HCl($X^1Σ^+$)-O$_{2}$($X^3Σ^-_g$) system: collision-induced line-shape parameters for O$_{2}$-perturbed R(0) 0-0 line in H$^{35}$Cl