What is the direction of the external electric field?

[Sharani]

The direction conventions followed by VASP aren't clear to me!

If I assign an external electric field of 0.1 eV/A to a system along its third lattice vector which happens to lie along the z-axis using:
EFIELD = 0.1
IDIPOL = 3
LDIPOL = .TRUE.

then will a test positive charge be pulled towards the +z or -z direction?

Also, if the dipole moment of a diatomic molecule is reported as 0.036 electron.Angstroms along the z-axis, does the negative end of the dipole point towards +z and the positive end towards -z direction?

Any information will be highly appreciated! Please help me!

Sharani.

[bandy]

I think if you use LDIPOL=.T. then you should set
DIPOL=center of mass by hand. In my opinion a test positive charge feel attractive force from -z direction. As I sent before the link(http://www.quantumchemistry.net/Experie ... 2/161.html), it seems the dipole moment directions of Gaussian (for HF -1.9338 Debye or -0.38676 e A) is opposite to VASP
(0.41107 e A). But I need to know whether I am right.
<span class='smallblacktext'>[ Edited Tue Aug 08 2006, 04:42PM ]</span>

[admin]

the dipole moment in VASP is given in e*A units.