Cr-Cu, Intermediate valence, Tripolyhedral, Trigonal

• Cr-Cu-O
• Cr-Cu-Mg-O
• magnetic properties
• electronic and electrical properties
• thermal and thermodynamic properties
• magnetic susceptibility
• Curie-Weiss paramagnetism
• transitional
• intermediate valence
• chalcogen
• antiferromagnetic
• tripolyhedral