Segfault in DMRG (user-defined site)

Question

Hi,

I'm trying to define my own SiteSet, basing on Hubbard (with two orbitals per site, and possibly an additional quantum number related to orbitals). The code compiles, but after running DMRG I get a segfault in first sweep. Depending on my initial state, I get it on different stages of first sweep. When running in debug mode, I get:

dmrg-g: /home/varelse/programs/itensor/itensor/itdata/qutil.h:190: void itensor::loopContractedBlocks(const BlockSparseA&, const IQIndexSet&, const BlockSparseB&, const IQIndexSet&, BlockSparseC&, const IQIndexSet&, Callable&) [with BlockSparseA = itensor::QDense; BlockSparseB = itensor::QDense; BlockSparseC = itensor::QDense; Callable = itensor::doTask(itensor::Contract&, const itensor::QDense&, const itensor::QDense&, itensor::ManageStore&) [with VA = double; VB = double]::<lambda(itensor::DataRange, const Labels&, itensor::DataRange, const Labels&, itensor::DataRange, const Labels&)>; itensor::IQIndexSet = itensor::IndexSetT]: Assertion `cblock' failed.

What could this error possibly mean?

(EDIT: I found the error - I defined my physical state IQIndex so that it had two subspaces of equal quantum numbers. )

Answer 1

Hi - glad to see you're trying some of the advanced features and that you found the error in your code. Let me know if you run into any other issues where I can help.

Miles