Comparative Study of Potassium Halides Parameters with Many Body and van der Waals Three Body Force Shell Model [VTBFSM]

2012 ◽  
Vol 2 (1) ◽  
pp. 35-47 ◽  
Author(s):  
U. Srivastava
Keyword(s):  
Comparative Study ◽  
Shell Model ◽  
Body Force ◽  
Van Der Waals ◽  
Many Body ◽  
Three Body ◽  
Potassium Halides

scholarly journals Lattice Dynamical Study of Platinum by Use of van der Waals Three Body Force Shell Model

2020 ◽  
Author(s):  
U C Srivastava
Keyword(s):  
Shell Model ◽  
Body Force ◽  
Present Model ◽  
Van Der Waals ◽  
Dynamical Study ◽  
Stiffness Constant ◽  
Phonon Spectra ◽  
Three Body ◽  
Rigid Shell ◽  
Fcc Structure

In present article author considered the lattice dynamical study of platinum by use of van der Waals three body force shell model [VTBFSM] due to high stiffness constant C11 and C12 . The present model uses with the frequencies of the optical and vibrational branches in the direction [100] and phonon density of states.The study of phonon spectra are important in determining the mechanica1, electrical and thermodynamical properties of elements and their alloys. The present model incorporates the effect of (VWI) and (TBI) into the rigid shell model with fcc structure, operative up to the second neighbors in short range interactions. The available measured data for platinum (Pt) well agrees with our results.

LATTICE DYNAMICS OF MgO USING THREE-BODY FORCE SHELL MODEL

1989 ◽  
Vol 03 (10) ◽  
pp. 771-776 ◽  
Author(s):  
S. MOHAN ◽  
T. RADJAKOUMAR
Keyword(s):  
Shell Model ◽  
Lattice Dynamics ◽  
Spectroscopic Data ◽  
Body Force ◽  
Phonon Dispersion ◽  
Many Body ◽  
Body Interaction ◽  
Lattice Potential ◽  
The Many ◽  
Three Body

A modified three-body force shell model is applied to evaluate the phonon dispersion values of MgO. The many-body interaction in the lattice potential is well accounted for by this theory. The values of the phonon frequencies evaluated by this method are in good confirmation with the neutron spectroscopic data.

LATTICE DYNAMICS OF TRANSITION METAL OXIDE MnO USING THREE BODY FORCE SHELL MODEL

1989 ◽  
Vol 03 (02) ◽  
pp. 115-118 ◽  
Author(s):  
S. MOHAN
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Shell Model ◽  
Body Force ◽  
Phonon Dispersion ◽  
Transition Metal Oxide ◽  
Many Body ◽  
Experimental Values ◽  
Three Body ◽  
Many Body Interactions

The phonon dispersion curve for the transition metal oxide viz. manganese oxide at room temperature has been calculated for the first time, assuming Mn ++ and O −− ions are highly polarisable. The three body force shell model employed here takes care of the effect of many body interactions in the lattice potential. The aim of this paper is to treat the various interactions between the ions in a more general way without making them numerically equal. The values of the phonon frequencies evaluated by the new approach are in general, in good agreement with the experimental values.

van der Waals three-body force shell model (VTSM) for the lattice dynamical studies of thallous bromide

2009 ◽  
Vol 80 (6) ◽  
pp. 065603 ◽  
Author(s):  
Sarvesh K Tiwari ◽  
L K Pandey ◽  
Lal Ji Shukla ◽  
K S Upadhyaya
Keyword(s):  
Shell Model ◽  
Body Force ◽  
Van Der Waals ◽  
Three Body

scholarly journals Nonempirical Interactions for the Nuclear Shell Model: An Update

2019 ◽  
Vol 69 (1) ◽  
pp. 307-362 ◽  
Author(s):  
S. Ragnar Stroberg ◽  
Heiko Hergert ◽  
Scott K. Bogner ◽  
Jason D. Holt
Keyword(s):  
Renormalization Group ◽  
Ab Initio ◽  
Shell Model ◽  
Model Parameters ◽  
Nuclear Shell Model ◽  
Many Body ◽  
Similarity Renormalization Group ◽  
Realistic Interaction ◽  
Three Body ◽  
Nuclear Shell

The nuclear shell model has perhaps been the most important conceptual and computational paradigm for the understanding of the structure of atomic nuclei. While the shell model has been used predominantly in a phenomenological context, there have been efforts stretching back more than half a century to derive shell model parameters based on a realistic interaction between nucleons. More recently, several ab initio many-body methods—in particular, many-body perturbation theory, the no-core shell model, the in-medium similarity renormalization group, and coupled-cluster theory—have developed the capability to provide effective shell model Hamiltonians. We provide an update on the status of these methods and investigate the connections between them and their potential strengths and weaknesses, with a particular focus on the in-medium similarity renormalization group approach. Three-body forces are demonstrated to be important for understanding the modifications needed in phenomenological treatments. We then review some applications of these methods to comparisons with recent experimental measurements, and conclude with some remaining challenges in ab initio shell model theory.

An extended three-body force shell model for the lattice-dynamics of ionic crystals

1976 ◽  
Vol 349 (1658) ◽  
pp. 289-308 ◽  
Keyword(s):  
Shell Model ◽  
Lattice Dynamics ◽  
Significant Contribution ◽  
Body Force ◽  
Cesium Chloride ◽  
Dynamical Matrix ◽  
Ionic Crystals ◽  
Range Overlap ◽  
Dynamical Description ◽  
Three Body

An extended three-body force shell model (e. t. s. m.) for the dynamics of ionic crystals of cesium chloride structure has been developed by reformulating the original t. s. m. The dynamical matrix of the model consists of the long-range Coulomb and three-body interactions and short-range overlap repulsions effective up to the second-neighbours. The off-diagonal elements of this matrix along symmetry directions contain a completely new term having significant contribution for unequal shell charges. The long-wave aspects of e. t. s. m. have been explored to describe the elastic and dielectric behaviour of the crystals. The adequacy of e. t. s. m. to describe the lattice dynamics has been investigated by applying it to the case of thallous bromide (TIBr). The overall agreement between theoretical and experimental results seems to be encouraging and gives some confidence to regard it as an appropriate model for the dynamical description of ionic crystals.

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