Search results for "Clusters"
showing 10 items of 1274 documents
Optical spectroscopy of X-ray sources in the Taurus molecular cloud: discovery of ten new pre-main sequence stars
2008
We have analyzed optical spectra of 25 X-ray sources identified as potential new members of the Taurus molecular cloud (TMC), in order to confirm their membership in this SFR. Fifty-seven candidates were previously selected among the X-ray sources in the XEST survey, having a 2MASS counterpart compatible with a PMS star based on color-magnitude and color-color diagrams. We obtained high-resolution optical spectra for 7 of these candidates with the SARG spectrograph at the TNG telescope, which were used to search for Li absorption and to measure the Ha line and the radial and rotational velocities; 18 low-resolution optical spectra obtained with DOLORES for other candidate members were used …
4,4'-[Thiophene-2,5-diylbis(ethyne-2,1-diyl)]dibenzonitrile
2008
In the solid state, the title compound, C₂₂H₁₀N₂S, forms centrosymmetric dimers by pairs of non-classical C-H...S hydrogen bonds linking approximately coplanar molecules. The benzene ring involved in this interaction makes a dihedral angle of only 7.21 (16)° with the thiophene ring, while the other benzene ring is twisted somewhat out of the plane, with a dihedral angle of 39.58 (9)°. The hydrogen-bonded dimers stack on top of each other with an interplanar spacing of 3.44 Å. C-H...N hydrogen bonds link together stacks that run in approximately perpendicular directions. Each molecule thus interacts with 12 adjacent molecules, five of them approaching closer than the sum of the van der Waals…
Novel Penning-trap techniques reveal isomeric states in $^{128}$In and $^{130}$In for the first time
2020
Isomeric states in $^{128}$In and $^{130}$In have been studied with the JYFLTRAP Penning trap at the IGISOL facility. By employing novel ion manipulation techniques, different states were separated and masses of six beta-decaying states were measured. JYFLTRAP was also used to select the ions of interest for identification at a post-trap decay spectroscopy station. A new beta-decaying high-spin isomer feeding the $15^-$ isomer in $^{128}$Sn has been discovered in $^{128}$In at $1797.6(20)$ keV. Shell-model calculations employing a CD-Bonn potential re-normalized with the perturbative G-matrix approach suggest this new isomer to be a $16^+$ spin-trap isomer. In $^{130}$In, the lowest-lying $…
High-quality variational wave functions for small He-4 clusters
1999
We report a variational calculation of ground state energies and radii for 4He_N droplets (3 \leq N \leq 40), using the atom-atom interaction HFD-B(HE). The trial wave function has a simple structure, combining two- and three-body correlation functions coming from a translationally invariant configuration-interaction description, and Jastrow-type short-range correlations. The calculated ground state energies differ by around 2% from the diffusion Monte Carlo results.
Excitation spectra of a He-3 impurity on He-4 clusters
2004
The diffusion Monte Carlo technique is used to calculate and analyze the excitation spectrum of a single 3He atom bound to a cluster with N 4He atoms, with the aim of establishing the most adequate filling ordering of single-fermion orbits to the mixed clusters with a large number of 3He atoms. The resulting ordering looks like the rotational spectrum of a diatomic molecule, being classified only by the angular momentum of the level, although vibrational-like excitations appear at higher energies for sufficiently large N.
Origin of discrepancy in theoretical value of polarizability correction to (mu-he-4)+ energy-levels
1976
Different approaches in calculating the polarizability correction to the energy levels of the muonic 4 He ion are compared. These calculations disagree with each other by giving results 3 to 10 times larger than the experimental uncertainty. The origin of the major discrepancy is traced to the treatment of the nuclear excitations. It is shown that the experimental value of the electric polarizability of 4 He provides a crucial restriction on model calculations.
Analysis of the Electronic Structure of Non-Spherical Ligand-Protected Metal Nanoclusters : The Case of a Box-Like Ag67
2017
In this work we introduce a new strategy to investigate the electronic shell structure of ligand-protected metal nanoclusters of polyhedral core shape. The central idea is to identify the symmetry of the Kohn–Sham molecular orbitals of an atomistic structure based on their projection onto the electronic states of a jellium system with a similar shape of the background charge density. Herein, we study the connection between a reduced atomistic model of the recently reported box-like [Ag67(SR)32(PR3)8]3+ nanocluster and a jellium box consisting of 32 free electrons. With this approach, we determine the symmetry of electronic states of the metal core and identify those that are involved in the…
The Dalton quantum chemistry program system
2013
Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, MOller-Plesset, confi ...
M9_Microfluidics_for_CNT
2018
The droplets in contact coalesce when exposed to DEP filed.
M10_Microfluidics_for_CNT
2018
Droplets are preferentially directed to the channel with higher flow rate in the passive sorting junction. When the droplets are exposed to DEP field, the DEP force pull them to the narrower channel.