The book is devoted to the analysis of spectral，vibronic and magnetic properties of3d ions in a wide range of crystals，used as active media for solid state lasers and potentialcandidates for this role.Crystal field calculations（including first-principles calculationsof energy levels and absorption spectra）and comparison of these results with experimentalspectra，Janh-Teller effect，analysis of vibronic spectra，materials science applicationsare systematically dealt with.The chapters are relatively independent and can be readseparately.The book can be useful for researchers working in the areas of crystal spectroscopy，materials science and its optical applications，post-graduate and under graduate students.