TeNPy Forum

Dear
Recently, I have started learning to implement infinite Density Matrix Renormalization Group (DMRG) calculations using the Tenpy library.
I would like to introduce an additional U(1) symmetry in the original `BosonSite`:
$$
P = \sum_j (L - j) n_j
$$
as detailed in equation (2) of [this paper](https://journals.aps.org/prb/abstract/1 ... 107.195131). Could you kindly advise on how to modify the `BosonSite` implementation to incorporate this symmetry?

Thank you for your time and guidance.

Hi,

These types of position dependent charges are not available in the live tenpy version yet

There is an unmerged PR at
https://github.com/tenpy/tenpy/pull/183

It seems, however, that it is not very stable for infinite systems and not tested well enough. I would not blindly trust it.

In the infinite case, its is particularly tricky to treat the position dependent local charges correctly.

We dont have capacity to work on this, currently.