Mixed halide scintillation materials of the general formula AB(1−y)MyX′wX″(3−w), where 0≤y≤1, 0.05≤w≤1, A may be an alkali metal, B may be an alkali earth metal, and X′ and X″ may be two different halogen atoms, and of the general formula A(1−y)BMyX′wX″(3−w), where 0≤y≤1, 0.05≤w≤1, A maybe an alkali metal, B may be an alkali earth metal, and X′ and X″ are two different halogen atoms. The scintillation materials of formula (1) include a divalent external activator, M, such as Eu2+ or Yb2+. The scintillation materials of formula (2) include a monovalent external activator, M, such as Tl+, Na+ and In+.