DIPOL: Difference between revisions
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For VASP.4.X behavior please refer to [[Monopole_Dipole_and_Quadrupole_corrections|Monopole, Dipole and Quadrupole corrections]]. | For VASP.4.X behavior please refer to [[Monopole_Dipole_and_Quadrupole_corrections|Monopole, Dipole and Quadrupole corrections]]. | ||
Description: calculate the total dipole-moment in the cell, using the option | |||
{{TAG|DIPOL}}='''R'''<sub>x</sub> '''R'''<sub>y</sub> '''R'''<sub>z</sub> | {{TAG|DIPOL}}='''R'''<sub>x</sub> '''R'''<sub>y</sub> '''R'''<sub>z</sub>, | ||
where '''R'''<sub>x</sub>, '''R'''<sub>y</sub> and '''R'''<sub>z</sub> specify the center of the cell in direct lattice coordinates. | where '''R'''<sub>x</sub>, '''R'''<sub>y</sub> and '''R'''<sub>z</sub>, to specify the center of the cell in direct lattice coordinates. | ||
---- | ---- | ||
Mind: the calculation of the dipole requires a definition of the center of the cell, and results might differ for different positions. | Mind: the calculation of the dipole requires a definition of the center of the cell, and results might differ for different positions. |
Revision as of 12:43, 3 September 2012
DIPOL = [real array]
Default: DIPOL = Template:FIXME
For VASP.4.X behavior please refer to Monopole, Dipole and Quadrupole corrections.
Description: calculate the total dipole-moment in the cell, using the option
DIPOL=Rx Ry Rz,
where Rx, Ry and Rz, to specify the center of the cell in direct lattice coordinates.
Mind: the calculation of the dipole requires a definition of the center of the cell, and results might differ for different positions. You should use this option only for surfaces and isolated molecules. In this case use the center of mass for the position (for surface only the component normal to the surface is meaningful).
The main problem is that the definition of the dipole 'destroys' the translational symmetry, i.e. the dipole is defined as
Now, this makes only sense if drops to zero at some distance from . If this is not the case, the values are extremely sensible with respect to changes in .