Jan N. Reimers

It looks like it is related to [GPU support enhancements](https://github.com/ITensor/ITensors.jl/commit/d7d6ec897586d48c624356b53054573e0286d396#diff-54a3468671071f1b6bdd9b5f64a92b16f4bbd68ce78561411a392f83fe14821d). Presumably the purpose of calling adapt is for adapting the precision of element type of the op to match precision...

CI fail seems to be related to ITensorGPU module: Spin-one Heisenberg: Error During Test at /home/jenkins/workspace/ITensors.jl_PR-1099/ITensorGPU/test/test_dmrg.jl:14 Got exception outside of a @test Format of __nvvm__reflect function not recognized

New fail in NDTensors unit test, after removeal of stale (unused) file in ITensors/test ?!?! Not reproducible at my end with Ubuntu/Julia 1.6 Did the lapack library in the CI...

Good point about the cutoff argument. It did not occur to me that I could use rr_cutoff for the MPO truncate function and then simply pass it as cutoff to...

It seems LAPACK only supports column pivoting for QR (and therefore indirectly for LQ), but not for QL/RQ. A table of supported orthogonal factorizations is here: https://netlib.org/lapack/lug/node44.html The MatrixFactorization.jl library...

Update from my end: I emailed Daniel Parker and he was glad to hear the ITensors team implementing his methods, and simultaneously a little skeptical that we can use pivoted...

The interface update using atol/rtol instead of cutoff is done. It looks like ITensorGPU/src/tensor/culinearalgebra.jl needs to also be updated to handle many of the recent changes. But I don't have...

Hi @LHerviou if you have some code to share for generating your MPO, I would be interested in putting it through the iMPO compression module to see what it can...

Hi Loic, good to hear from you. Yes the Ac/bA block orthogonalization using column pivoting QR is working well. I use your fqhe model as a tough unit test case....

I will experiment with adding a four site term to the Hubbard model (if opsum supports that?). Good thing to have in the unit tests anyway. I would be interested...