Hi,

I am using dmrg in the ITensor Julia version to calculate various excited states in the 1D spin system. There is a Z2 spontaneous symmetry breaking which should lead to two ground states. I was wondering whether dmrg output for ground state energy in ITensor provides both of these ground states ( one as ground state and the second ground state as an excited state) or a linear combination of them leads to ground state. I would like to know if there is any way to get both ground states rather than a linear combination.

Also, while calculating excited state energy using dmrg, how does the choice of "Weight" will impact the answer? What would be a good guess ( or approach) for choosing the value of "Weight" if a gap is closing between the excited state and ground state or the gap is very small?

Thank you so much,

Best,

Ajit