H-N-O-Se, Se-x polyhedra, Structural transitions

• H-N-Na-O-Se
• H-N-O-Se-Te
• temperature for structural transition
• pressure for structural transition
• pnictogen
• chalcogen
• tetraoxoselenate
• quaternary
• nonmetal
• triclinic
• monoclinic
• trigonal
• orthorhombic