Home › Forums › Hyperfine course › electric quadrupole interaction › case studies / symmetry – task 1 › Task2 This topic has 0 replies, 1 voice, and was last updated 1 year, 8 months ago by babet.vandingenen. Viewing 1 post (of 1 total) Author Posts March 20, 2023 at 10:12 pm #4420 babet.vandingenenParticipant For FeI there will be a 4-fold rotation symmetry in the vertical axis, and so eta is zero. For FeII the vertical axis has a 4-fold rotation symmetry as well so in this case, eta is also zero. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In