Hi all,

I want to claculate the Born effective charge tensors for alpha-quartze as menthioned in the GULP website(

http://projects.ivec.org/gulp/help/gulp_31_manual/gulpnode30.html)

but as I have calculated my tensor is far away from what mentioned in the website and they are symmetrical and none of those off diagonal factors are present there.

So whould you please let me know how can I exactly calculate the borne effective charges with GULP? Does it need me to have the partial charges of the atoms before calculating the born effective charge?

I have attached my input file here for your consideration too.

here is what I have gotten as Born effective charges tensor:

------------------------------------------------------------------------------

  Atom             x           y             z

-------------------------------------------------------------------------------

   1 O1    x      -0.6589      0.0000      0.0000

              y       0.0000     -0.6589      0.0000

              z       0.0000      0.0000     -0.6589

-------------------------------------------------------------------------------

   2 Si1   x       1.3178      0.0000      0.0000

             y       0.0000      1.3178      0.0000

             z       0.0000      0.0000      1.3178

-------------------------------------------------------------------------------