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 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.

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.

THERMOELASTIC BEHAVIOUR OF FLUORITE SOLIDS USING THREE-BODY FORCE SHELL MODEL

1992 ◽  
Vol 06 (19) ◽  
pp. 3179-3188 ◽  
Author(s):  
S. S. BEDI ◽  
MAJOR SINGH ◽  
JASPAL SINGH
Keyword(s):  
Shell Model ◽  
Elastic Constants ◽  
Body Force ◽  
Thermal Phonon ◽  
Third Order ◽  
Third Order Elastic Constants ◽  
Three Body ◽  
Body Potential ◽  
Derivatives Of ◽  
Theoretical Results

The expressions for the second and third order elastic constants of fluorite lattice are derived using Lundqvist three-body potential incorporating thermal phonon pressure and inter-sublattice displacement through the shell model. Theoretically calculated values of the third order elastic constants are compared with the theoretical results of other workers and experiments. First order pressure derivatives of the second order elastic constants calculated using Thurston and Brugger relations for Ca 1-x Sr x F 2 and Sr 1-x Ba x F 2 are found to be in agreement with the experiment.

Three-Body-Force Shell Model and the Lattice Dynamics of Magnesium Oxide

1973 ◽  
Vol 8 (10) ◽  
pp. 4880-4884 ◽  
Author(s):  
M. P. Verma ◽  
S. K. Agarwal
Keyword(s):  
Shell Model ◽  
Magnesium Oxide ◽  
Lattice Dynamics ◽  
Body Force ◽  
Three Body
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