# [Julia] QN Block Sparse ITensor gives wrong results for multiplying the delta tensor

+1 vote

Hi,

For the following code, the answer should be "4.0", but it gives "2.0". Maybe it is a bug. Thanks.

s = Index([QN(("N",i,1))=>1 for i = 1:2];dir = ITensors.Arrow(1))
A = emptyITensor(l,r,u,d)
A[1,1,1,1] = 1.0
A[1,1,2,2] = 1.0
A[2,2,1,1] = 1.0
A[2,2,2,2] = 1.0
println(A*delta(dag(l),dag(r))*delta(dag(u),dag(d)))


Jin

commented by (13.6k points)
Thanks for the report, I am seeing the same thing. I'll take a look.