I notice that this toExpH function is based on based on the following article: Phys. Rev. B 91, 165112 (arxiv:1407.1832) using the WI method. However , I want to use the WII method in that artical. So does ITensor have this function?
Hi, unfortunately no it does not, though it could be a nice thing to add.
One thing that might help you, though, is that in many cases the TDVP algorithm is a faster and much more accurate method for time evolving systems starting from an MPO. There is a nice TDVP code based on C++ ITensor here https://github.com/ITensor/TDVP. Also we are working on one that’s almost ready based on our Julia version of ITensor.