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The deuterium enrichment of molecules is sensitive to their formation environment. Constraining patterns of deuterium chemistry in protoplanetary disks is therefore useful for probing how material is inherited or reprocessed throughout the…

Deuterium fractionation in molecular ions, in particular HCO+, has been extensively used to estimate the degree of ionization in molecular clouds. This paper reviews recent work on ionization degree in homogeneous clouds. We will show that…

Astrophysics · Physics 2009-11-07 Paola Caselli

The crystal structure of potassium doped picene with an exact stoichiometry (K3C22H14, K3picene from here onwards) has been theoretically determined within Density Functional Theory allowing complete variational freedom of the crystal…

Materials Science · Physics 2011-10-10 P. L. de Andres , A. Guijarro , J. A. Verges

The de Sitter invariant Special Relativity (dS-SR) is a SR with constant curvature, and a natural extension of usual Einstein SR (E-SR). In this paper, we solved the dS-SR Dirac equation of Hydrogen by means of the adiabatic approach and…

General Physics · Physics 2012-05-23 Mu-Lin Yan

Quasicrystals have a higher degree of rotational and point-reflection symmetry than conventional crystals. As a result, quasicrystalline heterostructures fabricated from dielectric materials with micrometer-scale features exhibit…

Soft Condensed Matter · Physics 2009-11-11 Yael Roichman , David G. Grier

The ratio between the two stable isotopes of nitrogen, $^{14}$N and $^{15}$N, is well measured in the terrestrial atmosphere ($\sim 272$), and in the pre-Solar nebula ($\sim 441$). Interestingly, some pristine Solar System materials show…

Solar and Stellar Astrophysics · Physics 2018-02-07 L. Colzi , F. Fontani , P. Caselli , C. Ceccarelli , P. Hily-Blant , L. Bizzocchi

The orthorhombic crystal structure of the novel molecular-inorganic polymer $\mathrm{K_{2}SeO_{4}\cdot H_{2}SeO_{3}}$ was elucidated using single-crystal X-ray diffraction with MoK$\alpha$ radiation ($\lambda$= 0.71073 {\AA}), performed at…

We present the detection of deuterated molecular hydrogen (HD) in the remote Universe in a damped Lyman-alpha cloud at zabs=2.418 toward the quasar SDSS J143912.04+111740.5. This is a unique system in which H2 and CO molecules are also…

Astrophysics · Physics 2009-11-13 P. Noterdaeme , P. Petitjean , C. Ledoux , R. Srianand , A. Ivanchik

We employed density functional theory-based ab initio molecular dynamics simulations to examine the hydration structure of several common alkali and alkali earth metal cations. We found that the commonly used atom pairwise dispersion…

Chemical Physics · Physics 2023-09-08 Vojtech Kostal , Philip E. Mason , Hector Martinez-Seara , Pavel Jungwirth

The partially deuterated linear isomer HDCCC of the ubiquitous cyclic carbene ($c$-C$_3$H$_2$) was observed in the starless cores TMC-1C and L1544 at 96.9 GHz, and a confirming line was observed in TMC-1 at 19.38 GHz. To aid the…

Consider a projector matrix P, representing the first order reduced density matrix in a basis of orthonormal atom-centric basis functions. A mathematical question arises, and that is, how to break P into its natural component kernel…

Quantum Physics · Physics 2021-09-09 Cherif F. Matta , Lou Massa

The crystal structure of KAgF3 was studied by powder neutron diffraction. KAgF3 exhibits at all temperatures an orthorhombic symmetry in space group Pnma that allows for several distortions with respect to the ideal cubic perovskite…

We present sensitive observations of NH2D at 110.153599 GHz toward 50 Galactic massive star-forming regions with IRAM 30-m telescope. The NH2D transition is detected toward 36 objects, yielding a detection rate of 72%. Column densities of…

Astrophysics of Galaxies · Physics 2022-04-27 Yuqiang Li , Junzhi Wang , Juan Li , Shu Liu , Qiuyi Luo

Conclusive crystal structure determination of the high pressure phases of hydrogen remains elusive due to lack of core electrons and vanishing wave vectors, rendering standard high-pressure experimental methods moot. Ab-initio DFT…

Materials Science · Physics 2024-07-30 Meng Yang , Yishan Zhou , Rajesh Jana , Takeshi Nakagawa , Yunhua Fu , Thomas Meier

Plutonium dihydride and trihydride show strikingly similar crystal structures when viewed as close-packed Pu planes with ABC and AB stacking, respectively. The similarity serves as a framework for density functional theory (DFT)…

Materials Science · Physics 2013-07-03 Sven P. Rudin

The microscopic justification of the emergence of SU(3) symmetry in heavy nuclei remains an interesting problem. In the past, the pseudo-SU(3) approach has been used, with considerable success. Recent results seem to suggest that the key…

Nuclear Theory · Physics 2019-12-25 Dennis Bonatsos , I. E. Assimakis , Andriana Martinou

The formation of deuterated molecules is favoured at low temperatures and high densities. Therefore, the deuteration fraction D$_{frac}$ is expected to be enhanced in cold, dense prestellar cores and to decrease after protostellar birth.…

Astrophysics of Galaxies · Physics 2017-06-14 S. Zahorecz , I. Jimenez-Serra , L. Testi , K. Immer , F. Fontani , P. Caselli , K. Wang , L. V. Toth

Compact stars (CS) are stellar remnants of massive stars. Inside CSs the density is so high that matter is in subatomic form composed of nucleons. With increase of density of matter towards the centre of the objects other degrees of freedom…

High Energy Astrophysical Phenomena · Physics 2023-03-24 Anil Kumar , Vivek Baruah Thapa , Monika Sinha

We performed neutron powder diffraction experiments on lithium imide Li2NH, and have proposed a revised crystal structure model. Li2NH has a face-centered cubic structure with a partially occupied hydrogen site. Of the possible crystal…

Materials Science · Physics 2009-11-10 K. Ohoyama , Y. Nakamori , S. Orimo , K. Yamada

We have conducted the first extensive observational survey of several deuterated species in 16 Class 0/I proto-brown dwarfs (proto-BDs) and 4 Class Flat/Class II brown dwarfs. Observations were obtained with the IRAM 30m telescope in the…

Solar and Stellar Astrophysics · Physics 2022-02-02 B. Riaz , W. -F. Thi
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