Modifiers matching nitride:

• binary,
• ceramic,
• metal,
• refractory,
• pure,
• stable,
• conductive,
• exotic,
• piezoelectric,
• covalent,

Simple categories matching covalent:

• nitride,
• material,
• semiconductor,
• structure,
• chloride,
• atom,
• element,
• oxide,
• system,
• solid,
• metal,
• crystal,
• carbide,
• substance,
• compound,