APPLICATION OF VAN DER WAALS DENSITY FUNCTIONAL THEORY TO STUDY PHYSICAL PROPERTIES OF ENERGETIC MATERIALS

2009 ◽  
Author(s):  
M. W. Conroy ◽  
M. M. Budzevich ◽  
Y. Lin ◽  
I. I. Oleynik ◽  
C. T. White ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Physical Properties ◽  
Energetic Materials ◽  
Density Functional ◽  
Van Der Waals ◽  
Functional Theory

scholarly journals Van der Waals Density Functional Theory vdW-DFq for Semihard Materials

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 243 ◽  
Author(s):  
Qing Peng ◽  
Guangyu Wang ◽  
Gui-Rong Liu ◽  
Suvranu De
Keyword(s):  
Density Functional Theory ◽  
Energetic Materials ◽  
Density Functional ◽  
Energetic Material ◽  
Van Der Waals ◽  
Molecular Crystals ◽  
Soft Materials ◽  
Dispersion Force ◽  
Electronic Charge ◽  
Functional Theory

There are a large number of materials with mild stiffness, which are not as soft as tissues and not as strong as metals. These semihard materials include energetic materials, molecular crystals, layered materials, and van der Waals crystals. The integrity and mechanical stability are mainly determined by the interactions between instantaneously induced dipoles, the so called London dispersion force or van der Waals force. It is challenging to accurately model the structural and mechanical properties of these semihard materials in the frame of density functional theory where the non-local correlation functionals are not well known. Here, we propose a van der Waals density functional named vdW-DFq to accurately model the density and geometry of semihard materials. Using β -cyclotetramethylene tetranitramine as a prototype, we adjust the enhancement factor of the exchange energy functional with generalized gradient approximations. We find this method to be simple and robust over a wide tuning range when calibrating the functional on-demand with experimental data. With a calibrated value q = 1.05 , the proposed vdW-DFq method shows good performance in predicting the geometries of 11 common energetic material molecular crystals and three typical layered van der Waals crystals. This success could be attributed to the similar electronic charge density gradients, suggesting a wide use in modeling semihard materials. This method could be useful in developing non-empirical density functional theories for semihard and soft materials.

Controllable spin direction in nonmagnetic BX/MX2 (M = Mo or W; X = S, Se and Te) van der Waals heterostructures by switching between the Rashba splitting and valley polarization

2021 ◽  
Author(s):  
Dongxue Zhang ◽  
Baozeng Zhou
Keyword(s):  
Density Functional Theory ◽  
Physical Properties ◽  
Density Functional ◽  
Major Part ◽  
Condensed Matter ◽  
Van Der Waals ◽  
Functional Theory ◽  
Spin Direction ◽  
Spin Degree ◽  
Valley Polarization

Manipulating physical properties using the spin degree of freedom constitutes a major part of modern condensed matter physics and is a key aspect for spintronics devices. Using density functional theory...

scholarly journals Doping the Buckminsterfullerene by Substitution: Density Functional Theory Studies of C59X (X = B, N, Al, Si, P, Ga, Ge, and As)

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hongcun Bai ◽  
Wenxin Ji ◽  
Xiangyu Liu ◽  
Liqiong Wang ◽  
Nini Yuan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Physical Properties ◽  
Density Functional ◽  
Dielectric Constants ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Relative Stabilities ◽  
As Doping ◽  
Quantum Chemistry Calculations ◽  
Heteroatom Substitution

The heterofullerenes C59X (X = B, N, Al, Si, P, Ga, Ge, and As) were investigated by quantum chemistry calculations based on density functional theory. These hybrid cages can be seen as doping the buckminsterfullerene by heteroatom substitution. The geometrical structures, relative stabilities, electronic properties, vibrational frequencies, dielectric constants, and aromaticities of the doped cages were studied systemically and compared with those of the pristine C60cage. It is found that the doped cages with different heteroatoms exhibit various electronic, vibrational, and aromatic properties. These results imply the possibility to modulate the physical properties of these fullerene-based materials by tuning substitution elements.

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