An effective ion–ion potential for sodium

1970 ◽  
Vol 48 (12) ◽  
pp. 1480-1489 ◽  
Author(s):  
Z. S. Basinski ◽  
M. S. Duesbery ◽  
A. P. Pogany ◽  
Roger Taylor ◽  
Y. P. Varshni
Keyword(s):  
Matrix Element ◽  
Plane Wave ◽  
Excellent Agreement ◽  
Elastic Constants ◽  
Cohesive Energy ◽  
Electron Gas ◽  
Body Centered Cubic ◽  
Specific Heats ◽  
Ion Separation ◽  
Atomic Properties

The effective ion–ion interaction for sodium is calculated from a fundamental basis, using a one-orthogonalized plane wave (OPW) bare electron – ion matrix element, and the Geldart and Taylor electron gas screening function. Particular attention is paid to the form of the interaction for asymptotically large ion–ion separation, and it is shown that this interaction varies approximately as the fifth power of the ion–ion separation in the region in which the amplitude of the potential is appreciable. The elastic constants, cohesive energy, and the specific heats of body-centered cubic (b.c.c.) and close-packed sodium are shown to be in excellent agreement with experiment. The equilibrium and stability of the model sodium lattice described by the proposed potential are discussed, and it is concluded that the potential can be used tentatively in a fundamental calculation of atomic properties of defects.

FIRST-PRINCIPLES HIGH-PRESSURE ELASTIC AND THERMODYNAMIC PROPERTIES OF TANTALUM

2011 ◽  
Vol 25 (10) ◽  
pp. 1393-1407 ◽  
Author(s):  
JING-HE WU ◽  
XIAN-LIN ZHAO ◽  
YOU-LIN SONG ◽  
GUO-DONG WU
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Equations Of State ◽  
Debye Model ◽  
Thermal Expansivity ◽  
Orbital Method ◽  
Full Potential ◽  
Body Centered Cubic ◽  
Theoretical Results

The all-electron full-potential linearized muffin-tin orbital method, by means of quasi-harmonic Debye model, is applied to investigate the elastic constant and thermodynamic properties of body-centered-cubic tantalum (bcc Ta). The calculated elastic constants of bcc Ta at 0 K is consistent with the previous experimental and theoretical results. Our calculations give the correct trends for the pressure dependence of elastic constants. By using the convenient quasi-harmonic Debye model, we refined the thermal equations of state. The thermal expansivity and some other thermal properties agree well with the previous experimental and theoretical results.

Elastic constants of body-centered-cubic cobalt films

1994 ◽  
Vol 49 (24) ◽  
pp. 17319-17324 ◽  
Author(s):  
S. Subramanian ◽  
R. Sooryakumar ◽  
G. A. Prinz ◽  
B. T. Jonker ◽  
Y. U. Idzerda
Keyword(s):  
Elastic Constants ◽  
Body Centered Cubic ◽  
Cobalt Films

scholarly journals Understanding and solving disorder in the substitution pattern of amino functionalized MIL-47(V)

2016 ◽  
Vol 45 (10) ◽  
pp. 4309-4315 ◽  
Author(s):  
Jurn Heinen ◽  
David Dubbeldam
Keyword(s):  
Density Functional Theory ◽  
Plane Wave ◽  
Elastic Constants ◽  
Density Functional ◽  
Substitution Pattern ◽  
Functional Theory ◽  
Organic Linker

Electronic energies and elastic constants of four amino functionalized MIL-47(V) supercells were computed using the plane wave density functional theory to determine the influence of the substituent positions on the organic linker.

Elastic and Thermal Properties of SrCo1-xScxO3-δ

2014 ◽  
Vol 975 ◽  
pp. 283-287
Author(s):  
Rasna Thakur ◽  
Rajesh K. Thakur ◽  
N.K. Gaur
Keyword(s):  
Thermal Properties ◽  
Specific Heat ◽  
Debye Temperature ◽  
Elastic Constants ◽  
Cohesive Energy ◽  
Second Order ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter ◽  
Rigid Ion Model

We have investigated the elastic and thermal properties for perovskite SrCo1-xScxO3-d, by means of Modified Rigid Ion Model (MRIM). We have also computed the second order Elastic constants (SOECs) and their combinations. Besides we have reported the cohesive energy (f), Debye temperature (θD) and Gruneisen parameter (γ). The variation of specific heat (C) at temperature 15 K≤x≤1000 K is computed for SrCo1-xScxO3-d. The computed properties reproduce well with the available data in literature.

Elastic constants of the transition metals from a uniform electron gas

1994 ◽  
Vol 49 (17) ◽  
pp. 11588-11601 ◽  
Author(s):  
James H. Rose ◽  
Herbert B. Shore
Keyword(s):  
Transition Metals ◽  
Elastic Constants ◽  
Electron Gas ◽  
Uniform Electron Gas

The use of electron gas modification in the evaluation of the vibration frequencies and the specific heat of lithium

1960 ◽  
Vol 259 (1298) ◽  
pp. 361-369 ◽  
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Electron Gas ◽  
Vibration Frequencies ◽  
Specific Heats ◽  
Air Temperatures ◽  
Set Up ◽  
Good Agreement ◽  
Secular Determinant

A secular determinant for the determination of vibration frequencies of lithium has been set up by Launay’s method which takes the electron gas into account. Theoretical elastic constants have been used in the calculation of the force constants. Frequencies have been calculated for 47 points of the first Brillouin zone which gives the value of 3 x 1000 = 3000 frequencies by symmetry. Specific heats have been calculated by numerical computation in the range 300 to 6°K and show good agreement with the experimental data. The agreement below liquid-air temperatures is surprising in view of the known phase transformation of lithium.

An expansion method for calculating atomic properties IV. Transition probabilities

1964 ◽  
Vol 280 (1381) ◽  
pp. 258-270 ◽  
Keyword(s):  
Wave Function ◽  
Matrix Element ◽  
Transition Probabilities ◽  
Expansion Method ◽  
The State ◽  
Diagonal Matrix Element ◽  
Expectation Value ◽  
First Order ◽  
Hartree Fock ◽  
Atomic Properties

An earlier expression for the expectation value of a single-electron operator which isstationary with respect to first-order variations of the state wave function has been generalized to the case of an off-diagonal matrix element connecting two different states. Explicit calculations are carried out of the probabilities of dipole transitions between configurations 1 s a 2 s b 2 p c and 1 s a 2 s b–1 2 p c+1 for all members of the isoelectronic sequences from helium to neon and the importance of taking into account the mixing of degenerate configurations is demonstrated. The accuracy is at least comparable to that of the Hartree-Fock approximation and in cases where degeneracy is important it is much superior.

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