Consistency condition in the energy expression of the pseudopotential theory of metals and unified study of alkali metals

1983 ◽  
Vol 115 (2) ◽  
pp. 593-602 ◽  
Author(s):  
D. Sen ◽  
S. K. Sarkar ◽  
S. Sengupta ◽  
D. Roy
Keyword(s):  
Alkali Metals ◽  
Consistency Condition ◽  
Pseudopotential Theory ◽  
Energy Expression ◽  
Unified Study

Consistency condition in the energy expression of the pseudopotential theory of metals

1981 ◽  
Vol 24 (2) ◽  
pp. 876-883 ◽  
Author(s):  
D. Sen ◽  
S. K. Sarkar ◽  
D. Roy ◽  
S. Sengupta
Keyword(s):  
Consistency Condition ◽  
Pseudopotential Theory ◽  
Energy Expression

Structural energetics of heavy alkali metals: pseudopotential theory revisited

1984 ◽  
Vol 14 (4) ◽  
pp. 833-843 ◽  
Author(s):  
M Mazibar Rahman ◽  
S M Mujibar Rahman ◽  
S M M R Chowdhury
Keyword(s):  
Alkali Metals ◽  
Pseudopotential Theory

Unified study of metals on pseudopotential theory: Lead

1981 ◽  
Vol 107 (2) ◽  
pp. 559-567 ◽  
Author(s):  
D. Sen ◽  
S. K. Sarkar
Keyword(s):  
Pseudopotential Theory ◽  
Unified Study ◽  
Theory Lead

scholarly journals Investigation of some basic thermodynamic properties of Na-K alloy

BIBECHANA ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 1-8
Author(s):  
Rajesh C Malan ◽  
Aditya M Vora
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Local Field ◽  
Alkali Metals ◽  
Helmholtz Free Energy ◽  
Correlation Effect ◽  
The Other ◽  
Pseudopotential Theory ◽  
Local Field Correction ◽  
Energy Components

Investigation of thermodynamic of liquid binary alloys using pseudopotential theory is reported. The potential suggested by Fiolhais et al. with its individual parameters is used for the entire calculation. A transferability of the potential from the solid to liquid medium is achieved for the presently reported binary alloy. The internal energy components, Helmholtz free energy, entropy, and total energy at various proportions of the participating alkali metals are included in the study. The comparison with the other data has been shown in the present article. Exchange and correlation effect is also tested with the help of various local field correction functions. BIBECHANA 18 (2) (2021) 1-8

The Temperature Dependent Elastic Moduli of Liquid Potassium

2013 ◽  
Vol 209 ◽  
pp. 220-224
Author(s):  
Amit B. Patel ◽  
A.Y. Vahora ◽  
Nisarg K. Bhatt ◽  
Brijmohan Y. Thakore ◽  
P.R. Vyas ◽  
...  
Keyword(s):  
Alkali Metals ◽  
Memory Function ◽  
Pair Potential ◽  
Delta Function ◽  
Damping Factor ◽  
Simple Liquid ◽  
Small Momentum Transfer ◽  
Pseudopotential Theory ◽  
Different Temperatures ◽  
Elastic Reaction

Near the melting point liquid alkali metals show positive dispersion, which can be described within generalized hydrodynamics as a visco-elastic reaction of the simple liquid. To understand an upward bending of the dispersion relation at small momentum transfer, treatment of pseudopotential theory on liquid potassium is performed at different temperatures in entire liquid regime. In the present study, we used the modified empty core potential due to Hasegawa et al. along with a local field correction due to Ichimaru-Utsumi (IU) to explain an electron-ion interaction. The potential used is composed of a full electron-ion interaction and a repulsive delta function to incorporate the orthogonalisation effect due to the s-core states. The temperature dependence of pair potential is calculated by using the damping term, exp(-πkBTr/2kF). While the expression for phonon dispersions are derived within the memory function formalism. Results for longitudinal phonon frequencies, and thus derived sound velocities and elastic modulii are compared with recent inelastic X-ray scattering experiment. It is found sufficient to carried temperature effect into the description only via the damping factor, keeping the volume of normal melting.

Transport in some Alkalis

1971 ◽  
Vol 49 (14) ◽  
pp. 1952-1966 ◽  
Author(s):  
B. Hayman ◽  
J. P. Carbotte
Keyword(s):  
Alkali Metals ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Frequency Distributions ◽  
Pseudopotential Theory ◽  
Electrical Resistivities ◽  
The One ◽  
Analysis Of Dispersion ◽  
Uniform Scaling ◽  
Measured Volume

We have calculated the constant pressure and constant volume ideal electrical resistivities of the alkali metals Na, K, and Rb. In addition we have also calculated the ideal thermal resistivities of K and Rb. Information about the phonons is taken from a Born – von Kármán force constant analysis of dispersion curves at a particular temperature, obtained from inelastic neutron scattering. The shifts in phonon frequencies with volume are accounted for, approximately, by a uniform scaling using the known Grunëisen parameter and the measured volume changes. The electron–ion interaction is treated in pseudopotential theory and the one parameter Ashcroft form is used throughout. The calculations are reformulated in terms of two "transport frequency distributions", [Formula: see text] and [Formula: see text], which allow volume and temperature effects to be treated simply. The results compare very favorably with experiment over a wide temperature range.

ON THE PHASE STABILITY OF ALKALI METALS UNDER EXTERNAL PRESSURE

1993 ◽  
Vol 07 (01n03) ◽  
pp. 305-308
Author(s):  
BEKIR KARAOGLU ◽  
S. M. MUJIBUR RAHMAN
Keyword(s):  
Phase Stability ◽  
Alkali Metals ◽  
Structural Phase ◽  
Pair Potential ◽  
External Pressure ◽  
Simultaneous Application ◽  
Pseudopotential Theory ◽  
Spherical Waves ◽  
Total Energies ◽  
The Stability

Structural phase stability of certain alkali metals under external pressure is investigated in terms of the pseudopotential and augmented-spherical-waves (ASW) methods. The pair potential trend and the free energy differences between structures — both treated in a second-order pseudopotential theory — are invoked to explain qualitatively some aspects of the stability of the underlying phases at various pressures. Simultaneously, the ASW method is employed to compute the total energies and density-of-states (DOS) at the Fermi level for the phases concerned. The calculated differences in total energies between structures and the DOS curves shade some light in understanding the phase stability of the alkali metals under pressure. The simultaneous application of a perturbative and a nonperturbative treatment on the same footing has brought along some unified concluding remarks in dealing with this particular problem of phase stability.

Interionic Pair Potential, hard sphere diameter and entropy of mixing of NaCd compound forming binary molten alloys under the framework of Pseudopotential theory

2014 ◽  
Vol 10 (6) ◽  
pp. 2843-2852
Author(s):  
Sujeet Kumar Chatterjee ◽  
Lokesh Chandra Prasad ◽  
Ajaya Bhattarai
Keyword(s):  
Nearest Neighbor ◽  
Effective Interaction ◽  
Pair Potential ◽  
Sphere Diameter ◽  
Compound Formation ◽  
Pseudopotential Theory ◽  
Energy Of Mixing ◽  
Asymmetric Behaviour ◽  
Statistical Mechanical ◽  
Free Energy Of Mixing

The observed asymmetric behaviour of mixing of  NaCd liquid alloys around equiatomic composition with smaller negative values for free energy of mixing at compound forming concentration, i.e. GMXS = -4.9KJ at Ccd =0.66 has  aroused our interest to undertake a theoretical investigation of this system.A simple statistical mechanical theory based on compound formation model has been used to investigate the energetics of formation of intermetallic compound Cd2Na in the melt through the study of entropy of mixing.Besides, the interionic interactions between component atoms Na and Cd of the alloys have been understood through the study of interionic pair potential фij(r), calculated from pseudopotential theory in the light of CF model.Our study of фij(r) suggest that the effective interaction between Na-Na atoms decreases on alloying with Cd atom, being minimum for compound forming alloy( Cd 0.66 Na 0.34 ).The nearest neighbor distance between Na-Na atoms does not alter on alloying. Like wise Na-Na,  effective interaction between  Cd-Cd atom decreases from pure state to NaCd alloys, being smaller at compound forming  concentration Cd 0.66 Na 0.34.The computed values of SM from pseudopotential theory are positive at all concentrations, but the agreement between theory and experimental is not satisfactory. This might be happening due to parameterisation of σ3 and Ψcompound.

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