Dear Cheng-chau, you might find this post helpful: http://www.democritos.it/pipermail/pw_forum/2009-August/013827.html
As for the gas phase, if you have a polar molecule you could have its dipole along one axis and choose edir accordingly. Also have a look to the input parameter "assume_isolated", especially for charged species. HTH Guido On 07/24/2012 04:32 PM, Cheng-chau Chiu wrote: > Dear pw_scf users, > I am performing slab model calculations. I want to take account for the > fact, that the calculated system is also periodical in the direction > perpendicular to the suface of the slab, by adding a dipol correction in > that direction. So is it right, that the i have to set tefield and > dipfield to .TRUE., of doing so? If so, is it convinient to use the > default settings for eamp, emaxpos and eopreg? > Another question related to that is, if I am perfoming a "gas phase" > calcualtion (single molecule in a 20A*20A*20A unit cell) I might need > to apply dipole correction in all three directions. How can I do this? > It seems (as far as I have understood the QE documentation) that I can > only apply the correction in one direction at a time by setting > edir=1,2, or 3. > Thank you in advance, > > Cheng-chau Chiu, PhD-Student > TU Muenchen > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Guido Fratesi Dipartimento di Scienza dei Materiali Universita` degli Studi di Milano-Bicocca via Cozzi 53, 20125 Milano, Italy
