Alkali earth metal 1 Alkaline-earth metals 1 Balanced property Chalcopyrite-like structure 1 Combinations of structures 1 Copper compounds 1 Energy gap 1 Gallium compounds 1 Harmonic generation 1 Laser damage 1 Magnesium compounds 1 Nonlinear optical crystal 1 Nonlinear optical materials 1 Nonlinear optics 1 Optical materials 1 Phase matching 1 Selenium compounds 1 Silver compounds 1 Structure experiment 1 Structure prediction 1 Tetrahedral unit 1 alkaline earth metals 1 chalcogenide 1 chalcopyrite-like structures 1 nonlinear optical materials 1 tetrahedral units 1