Dear Prof. Baroni Excuse me if I was hasty. I mean the Hessian matrix(second-order partial derivatives) of the charge density (as a scalar field) in the unit cell (at FFT points).
Thanks for your attention (Mrs.) shekoufe Khosravi PhD student Isfahan University of Technology -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100406/1642eb23/attachment.htm
