This document specify Chempat as a generic family of instantiated Post-Quantum/Traditional (PQ/T) Hybrid Key Exchange Methods (KEMs). The goal is to provide a generic combiner construct that can be analysed separately for security assurance, and to offer concrete instantiated algorithms for integration into protocol and implementations. Identified instances are provided based on some combinations of traditional Diffie-Hellman key agreement using curves P-256, P-384, X25519, X448, brainpoolP256, brainpoolP384 and brainpoolP512 combined with post quantum methods ML-KEM-768, ML-KEM- 1024, Streamlined NTRU Prime sntrup761, Classic McEliece and FrodoKEM.