Orthogonal contravariant and covariant satisfy
 |
where 
is the Kronecker delta.
Orthogonal Tensors
See also
Contravariant Tensor, Covariant TensorExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Orthogonal Tensors." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/OrthogonalTensors.html