Prediction of a Very Hard Triclinic Form of Diamond

1995 ◽  
Vol 408 ◽  
Author(s):  
G. Benedek ◽  
M. Facchinetti ◽  
L. Miglio ◽  
S. Serra
Keyword(s):  
Molecular Dynamics ◽  
Ground State ◽  
Tight Binding ◽  
Cubic Phase ◽  
Ground State Structure ◽  
State Structure ◽  
Carbon Structure ◽  
Electronic Density ◽  
Phonon Spectra ◽  
Triclinic Form

AbstractIn a theoretical search for new hypotetical sp3-bonded carbon structure containing five-fold rings as a possible result of fullerene transformation under pressure, we have found a triclinic form of diamond with 16 atoms per unit cell which we called tcl-16. We have calculated the ground state structure, the cohesive energy, the bulk modulus and the electronic density of states by means of tight binding molecular dynamics (TBMD). Finally we have compared the phonon spectra at F to existing Raman data for a non-cubic- phase of diamond.

A density functional study of Rh13

2013 ◽  
Vol 91 (7) ◽  
pp. 591-597 ◽  
Author(s):  
Patrizia Calaminici ◽  
José M. Vásquez-Pérez ◽  
Diego A. Espíndola Velasco
Keyword(s):  
Molecular Dynamics ◽  
Ground State ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Functional Study ◽  
Ground State Structure ◽  
State Structure ◽  
Generalized Gradient ◽  
Density Functional Study

A density functional study was performed for the Rh13 cluster using the linear combination of Gaussian-type orbitals density functional theory (LCGTO-DFT) approach. The calculations employed both the local density approximation (LDA) as well as the generalized gradient approximation (GGA) in combination with a quasi-relativistic effective core potential (QECP). Initial structures for the geometry optimization were taken along Born–Oppenheimer molecular dynamics (BOMD) trajectories. The BOMD trajectories were performed at different temperatures and considered different potential energy surfaces (PES). As a result, several hundred isomers of the Rh13 cluster in different spin multiplicities were optimized with the aim to determine the lowest energy structures. All geometry optimizations were performed without any symmetry restriction. A vibrational analysis was performed to characterize these isomers. Structural parameters, relative stability energy, harmonic frequencies, binding energy, and most relevant Kohn–Sham (KS) molecular orbitals are reported. The obtained results are compared with available data from the literature. This study predicts a low symmetry biplanarlike structure as the ground-state structure of Rh13 with 11 unpaired electrons. This isomer was first noticed by inspection of first-principle Born–Oppenheimer molecular dynamics (BOMD) simulations between 300 and 600 K. This represents the most extensive theoretical study on the ground-state structure of the Rh13 cluster and underlines the importance of BOMD simulations to fully explore the PES landscapes of complicated systems.

Structural heterogeneity in a parent ground-state structure of AnPixJg2 revealed by theory and spectroscopy

2017 ◽  
Vol 19 (21) ◽  
pp. 13882-13894 ◽  
Author(s):  
Laura Katharina Scarbath-Evers ◽  
Sascha Jähnigen ◽  
Hossam Elgabarty ◽  
Chen Song ◽  
Rei Narikawa ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Ground State ◽  
Spectroscopic Properties ◽  
Structural Heterogeneity ◽  
Ground State Structure ◽  
State Structure ◽  
Dynamics Simulations

Extensive molecular dynamics simulations reveal two distinct isoforms of the cyanobacteriochrome AnPixJg2 (in its Pr state) with different chromophore conformations, yielding implications for spectroscopic properties.

Electronic Absorption and Ground State Structure of Carotenoid Molecules

2013 ◽  
Vol 117 (38) ◽  
pp. 11015-11021 ◽  
Author(s):  
Maria M. Mendes-Pinto ◽  
Elodie Sansiaume ◽  
Hideki Hashimoto ◽  
Andrew A. Pascal ◽  
Andrew Gall ◽  
...  
Keyword(s):  
Electronic Absorption ◽  
Ground State ◽  
Ground State Structure ◽  
State Structure

scholarly journals FIELD DECOMPOSITION AND THE GROUND STATE STRUCTURE OF SU(2) YANG–MILLS THEORY

2002 ◽  
Vol 17 (25) ◽  
pp. 3681-3688 ◽  
Author(s):  
LISA FREYHULT
Keyword(s):  
Effective Potential ◽  
Ground State ◽  
Scalar Fields ◽  
Background Field ◽  
Field Method ◽  
Gauge Fields ◽  
Ground State Structure ◽  
State Structure ◽  
Yang Mills ◽  
Background Field Method

We compute the effective potential of SU(2) Yang–Mills theory using the background field method and the Faddeev–Niemi decomposition of the gauge fields. In particular, we find that the potential will depend on the values of two scalar fields in the decomposition and that its structure will give rise to a symmetry breaking.

Theoretical Study on the Ground State Structure of Uranofullerene U@C82

2012 ◽  
Vol 116 (47) ◽  
pp. 11651-11655 ◽  
Author(s):  
Xin Liu ◽  
Lin Li ◽  
Bo Liu ◽  
Dongqi Wang ◽  
Yuliang Zhao ◽  
...  
Keyword(s):  
Ground State ◽  
Theoretical Study ◽  
Ground State Structure ◽  
State Structure
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