It should be helpful to know if the same phenomenon (which seems to me clearly pathological) exists in an unmodified version of QE and with K_POINT gamma as well. P. --- Paolo Giannozzi, Dept of Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222