Hi, My doubt may be trivial,as I cannot find the answer anywhere.
When does one needs to fix the value of the spin in LSDA calculation? multiplicity INTEGER ( default = 0 [unspecified] ) spin multiplicity (2s+1). 1 is singlet, 2 for doublet etc. Note that this fixes the final value of the magnetization. if unspecified or a non-zero value is specified in nelup/neldw then multiplicity variable is ignored. In particular, I am interested in the case of impurities in surfaces. Should I fix the spin in this case or not? Other case is dimers and clusters. I have answered this question to senior quantum chemists and I have received answers like a) Whith Hartree-Fock equations you must specify the spin, and DFT works well when HF does, and fails when HF fails. b) The states measured by spectroscopy have well defined S_z and S^2. So you want to calculate these states. Is there any other (and more fundamental) reason? Polite request: Avoid send Word attachments. To see why, take 6 minutes to read at http://www.gnu.org/philosophy/no-word-attachments.html Eduardo A. Menendez Proupin Department of Physics Faculty of Science University of Chile Las Palmeras 3425 ?u?oa, Santiago Chile Phone: (56)(2) 978 74 11 Fax : (56)(2) 271 29 73 http://fisica.ciencias.uchile.cl/~emenendez/
