I am trying to implement a simple version of iTebd. I defined a class which involves tensors Gamma with three indexes and tensors Lambda, which are real diagonal and contain the Schmidt eigenvalues. I have one of these tensors for each site in the elementary cell.

In order to exploit the advantage of having Lambda diagonal, I defined them using diagTensor.

In performing products of these tensors, I encountered the situation where I needed to change the indexes of one Lambda tensor. Therefore I performed the contraction with the sparse tensor delta.

However, I was surprised by the runtime error that I got when performing this contraction:

libc++abi.dylib: terminating with uncaught exception of type itensor::ITError: doTask not defined for task Contract and storage types DiagReal DiagReal

It seems that the product between two diagonal tensors is not implemented. Why is it so?