DFT-ulg: Difference between revisions

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In the DFT-ulg method of Kim et al.{{cite|kim:jpcl:2012}}, the correction term takes the form:
In the DFT-ulg method of Kim et al.{{cite|kim:jpcl:2012}}, the correction term takes the form:


:<math>E_{\mathrm{disp}} = -\frac{1}{2}  s_{lg}\sum_{i=1}^{N_{at}} \sum_{j=1}^{N_{at}}  \sum_{\mathbf{L}} {}^{\prime}  \frac{2D_{0}^{ij}(R_{0}^{ij})^{6}}{r_{ij,L}^{6}+b_{lg}(R_{0}^{ij})^{6}} </math>
:<math>E_{\mathrm{disp}} = -\frac{1}{2}  s_{lg}\sum_{i=1}^{N_{at}} \sum_{j=1}^{N_{at}}  \sum_{\mathbf{L}} {}^{\prime}  \frac{C_{6ij}}{r_{ij,L}^{6}+b_{lg}(R_{0}^{ij})^{6}} </math>


where the first two summations are over all <math>N_{at}</math> atoms in the unit cell and the third summation is over all translations of the unit cell <math>{\mathbf{L}}=(l_1,l_2,l_3)</math> where the prime indicates that <math>i\not=j</math> for <math>{\mathbf{L}}=0</math>.  
where the first two summations are over all <math>N_{at}</math> atoms in the unit cell and the third summation is over all translations of the unit cell <math>{\mathbf{L}}=(l_1,l_2,l_3)</math> where the prime indicates that <math>i\not=j</math> for <math>{\mathbf{L}}=0</math>.  

Revision as of 16:18, 1 February 2023

In the DFT-ulg method of Kim et al.[1], the correction term takes the form:

[math]\displaystyle{ E_{\mathrm{disp}} = -\frac{1}{2} s_{lg}\sum_{i=1}^{N_{at}} \sum_{j=1}^{N_{at}} \sum_{\mathbf{L}} {}^{\prime} \frac{C_{6ij}}{r_{ij,L}^{6}+b_{lg}(R_{0}^{ij})^{6}} }[/math]

where the first two summations are over all [math]\displaystyle{ N_{at} }[/math] atoms in the unit cell and the third summation is over all translations of the unit cell [math]\displaystyle{ {\mathbf{L}}=(l_1,l_2,l_3) }[/math] where the prime indicates that [math]\displaystyle{ i\not=j }[/math] for [math]\displaystyle{ {\mathbf{L}}=0 }[/math].

  • VDW_RADIUS=50.0 : cutoff radius (in [math]\displaystyle{ \AA }[/math]) for pair interactions
  • VDW_S6=0.7012 : global scaling factor [math]\displaystyle{ s_{lg} }[/math] (available in VASP.5.3.5 and later)
  • VDW_D=0.6966 : damping parameter [math]\displaystyle{ b_{lg} }[/math]
  • VDW_C6=[real array] : [math]\displaystyle{ C_6 }[/math] parameters ([math]\displaystyle{ \mathrm{Jnm}^{6}\mathrm{mol}^{-1} }[/math]) for each species defined in the POSCAR file
  • VDW_R0=[real array] : [math]\displaystyle{ R_0 }[/math] parameters ([math]\displaystyle{ \AA }[/math]) for each species defined in the POSCAR file
  • LVDW_EWALD=.FALSE. : the lattice summation in [math]\displaystyle{ E_{\mathrm{disp}} }[/math] expression is computed by means of Ewald's summation (.TRUE. ) or via a real space summation over all atomic pairs within cutoff radius VDW_RADIUS (.FALSE.). (available in VASP.5.3.5 and later)

Related tags and articles

VDW_RADIUS, VDW_S6, VDW_D, VDW_C6, VDW_R0, LVDW_EWALD, IVDW

References