Vector basis Orthonormal basis In an Inner product space (π,π,β¨β |β β©) an orthonormal basis is a vector basis that is an Orthonormal set, linalg i.e. orthogonal to each other with norm 1. In a countable basis {π£π}πββ the basis vectors obey the orthogonality relation β¨π£π|π£πβ©=πΏππ where πΏππ is the Kronecker delta. tidy | en | SemBr