10 research outputs found
Correction: A topological path to the formation of a quasi-planar B 70 boron cluster and its dianion
Get PDFThe Cartesian coordinates of B70 isomers were incorrectly included in the ESI file of this article. A revised ESI file has been uploaded. These structures had been reported previously in references 33, 40 and 41. The work on neutral B70 isomers was part of Pinaki Saha’s thesis and done in collaboration with Amol Rahane, N. Sukumar, and Vijay Kumar. In addition, the authors regret that the reference for 41b was given incorrectly. The correct reference is given below. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers
Electronic Origin of the Stability of Transition-Metal-Doped B14 Drum-Shaped Boron Clusters and Their Assembly into a Nanotube
No full textstatus: Published onlin
Structural and Electronic Properties of (Al<sub>2</sub>O<sub>3</sub>)<sub><i>n</i></sub> Clusters with <i>n</i> = 1–10 from First Principles Calculations
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Electronic Origin of the Stability of Transition-Metal-Doped B<sub>14</sub> Drum-Shaped Boron Clusters and Their Assembly into a Nanotube
No full textWe
study the stability of drum-shaped transition metal (TM)-doped
boron clusters, M@Bn with n = 14 and 16, and M = 3d, 4d, and 5d TM atom using ab initio calculations. Our results show that drum-shaped M@B14 clusters are favored for M = Cr, Mn, Fe, Co, and Ni, while in other
cases, open conical or bowl shaped structures become more favorable.
The isoelectronic Ni@B14 and Co@B14– clusters have large highest occupied molecular orbital–lowest
unoccupied molecular orbital gaps and these are magic clusters. Their
stability has been correlated with the occurrence of magic behavior
with 24 valence electrons in a disk jellium model, while for Fe@B14 case the drum structure is deformed and the stability occurs
at 22 delocalized valence electrons. The bonding nature in these clusters
has been studied by analyzing the electron density at bond and ring
critical points, the Laplacian distribution of the electron density,
the electron localization function, the source function, and electron
localization-delocalization indices, all of which suggest two- and
three-center σ bonding within and between the two B7 rings, respectively, and hybridization between the TM d orbitals
and the π bonded molecular orbitals of the drum. The infrared
and Raman spectra of these magic clusters show all real frequencies,
suggesting the dynamical stability of the drum-shaped structures.
There is a low frequency mode associated with the M atom. Results
of the electronic spectra of the anion clusters are also presented
that may help to identify these species in future experiments. Further,
we discuss the stability of 24 delocalized valence electron systems
Mn@B16 anion, Fe@B16, Co@B16 cation,
and other related clusters. Assembly of Co@B14 clusters
has been shown to stabilize a carbon nanotube-like nanotube of boron
with Co atomic nanowire inside while a nanotube of boron with triangular
network has been obtained with the assembly of Fe@B16 drum-shaped
clusters. Both the nanotubes are metallic
First Principles Calculations for Structural, Electronic, and Magnetic Properties of Gadolinium-Doped Alumina Clusters
No full textAtomic structures and physical properties of Gd-doped
alumina clustersnamely,
GdAl2n–1O3n and Gd2Al2n–2O3n with n = 1–10have
been studied within the framework of spin-polarized density functional
theory and the projector augmented wave pseudopotential method. We
find that the atomic structures of the host clusters (Al2O3)n are not changed significantly
by the substitutional doping of a Gd atom on Al sites. Our results
show that in the size range of the clusters we studied, a Gd atom
prefers a maximum 4-fold-coordinated Al-site, except for n = 8, in which a 5-fold-coordinated Al site is favored. The substitution
of Al with Gd atom is energetically favorable. This is in contrast
to the substitutional doping of Gd in the bulk alumina corundum structure
that is endothermic. There is a net magnetic moment of 7 μB per Gd atom, which is mostly localized on the Gd atom. Further
substitution of an Al atom with Gd in GdAl2n–1O3n clusters results in
the lowest-energy configuration's being either ferromagnetic or antiferromagnetic,
the difference between the two magnetic states being very small. The
variation in the magnetic state is found to be associated with the
variation in the coordination number of Gd atoms and the sites of
the two Gd atoms. Our results suggest that Gd doping of nanoparticles
offers an interesting way to prepare Gd-doped ceramic materials
Proceedings of National Conference on Relevance of Engineering and Science for Environment and Society
Get PDFThis conference proceedings contains articles on the various research ideas of the academic community and practitioners presented at the National Conference on Relevance of Engineering and Science for Environment and Society (R{ES}2 2021). R{ES}2 2021 was organized by Shri Pandurang Pratishthan’s, Karmayogi Engineering College, Shelve, Pandharpur, India on July 25th, 2021.
Conference Title: National Conference on Relevance of Engineering and Science for Environment and SocietyConference Acronym: R{ES}2 2021Conference Date: 25 July 2021Conference Location: Online (Virtual Mode)Conference Organizers: Shri Pandurang Pratishthan’s, Karmayogi Engineering College, Shelve, Pandharpur, India
