Related papers: Where are Protons and Deuterons in KH_pD_{1-p}CO_3…

We report two detections of deuterated molecular hydrogen (HD) in QSO absorption-line systems at $z > 2$. Toward J2123-0500, we find $N$(HD) $= 13.84 \pm 0.2$ for a sub-DLA with metallicity $\simeq 0.5Z_{\odot}$ and $N$(H$_2$) = $17.64 \pm…

Deuterium fractionation is known to enhance the [DCO+]/[HCO+] abundance ratio over the D/H elemental ratio of about 1e-5 in the cold and dense gas typically found in pre-stellar cores. We report the first detection and mapping of very…

(Abridged) The water deuterium fractionation (HDO/H$_2$O abundance ratio) has traditionally been used to infer the amount of water brought to Earth by comets. Measuring this ratio in deeply-embedded low-mass protostars makes it possible to…

The crystal structures of the triangular lattice, layered anhydrous alums KCr(SO4)2, RbCr(SO4)2 and KAl(SO4)2 are characterized by X-ray and neutron powder diffraction at temperatures between 1.4 and 773 K. The compounds all crystallize in…

The crystal structures of potassium and cesium bistrifluoroacetates were determined at room temperature and at 20 K and 14 K, respectively, with the single crystal neutron diffraction technique. The crystals belong to the I2/a and A2/a…

We use spectra and maps of the $J=1-0$ and $J=2-1$ DCO$^{+}$, DCN, DNC, $\rm N_2D^+$ lines and $1_{11}-1_{01}$ ortho- and para-NH$_{2}$D lines, obtained with the IRAM-30m telescope, as well as observations of their hydrogenated…

We present new models of the deuterium chemistry in protoplanetary disks, including, for the first time, multiply deuterated species. We use these models to explore whether observations in combination with models can give us clues as to…

Neutron Compton Scattering measurements presented here of the momentum distribution of hydrogen in $KH_2PO_4$ (KDP) just above and well below the ferroelectric transition temperature show clearly that the proton is coherent over both sites…

Here we present neutron diffraction results on the mineral azurite. We have found that the crystal structure of azurite can be described in the space group $P2_1$ which is the next lower symmetric group of $P2_1/c$ as found in earlier work.…

We have investigated the two-dimensional (R,Z) distribution of deuterated molecular species in circumstellar disks around young stellar objects. The abundance ratios between singly deuterated and normal molecules (``D/H ratios'') in disks…

Deuterated molecules and their molecular D/H-ratios (RD(D)) are important diagnostic tools to study the physical conditions of star-forming regions. The degree of deuteration, RD(D), can be significantly enhanced over the elemental…

Deuterium fractionation provides a key diagnostic of the physical and chemical evolution of prestellar and protostellar cores, where it is strongly linked to CO depletion in cold, dense gas. We present the first spatially resolved maps of…

The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered…

H3+ and the deuterated isotopomers are thought to play an important role in interstellar chemistry. The partition functions of H3+, D2H+ and D3+ are calculated to a temperature of 800 K by explicitly summing the ab initio determined…

The chemical evolution in high-mass star-forming regions is still poorly constrained. Studying the evolution of deuterated molecules allows to differentiate between subsequent stages of high-mass star formation regions due to the strong…

High levels of deuterium fractionation of $\rm N_2H^+$ (i.e., $\rm D_{frac}^{N_2H^+} \gtrsim 0.1$) are often observed in pre-stellar cores (PSCs) and detection of $\rm N_2D^+$ is a promising method to identify elusive massive PSCs. However,…

Proton-proton correlations and correlations of protons, deuterons and tritons with alpha particles from spectator decays following 197Au + 197Au collisions at 1000 MeV per nucleon have been measured with two highly efficient detector…

Neutron and x-ray diffraction measurements are presented for powders and single crystals of CaCo{1.86}As2. The crystal structure is a collapsed-tetragonal ThCr2Si2-type structure as previously reported, but with 7(1)% vacancies on the Co…

The Caltech Submillimeter Observatory has detected triply deuterated ammonia, ND3, through its 10a-00s transition near 310 GHz. Emission is found in the NGC 1333 region, both towards IRAS 4A and a position to the South-East where DCO+…

The possible use of high-resolution rovibrational spectroscopy of the hydrogen molecular ions H + 2 and HD + for an independent determination of several fundamental constants is analyzed. While these molecules had been proposed for…