I am working on a system of fermions, where the Hamiltonian can be written as a non-interacting Fermi gas by changing the basis. I am using quspin to do exact diagonalization, and what I need to do is to define a new basis where the states are linear combinations of the states in spinless_fermion_basis_1d. I have read the documentation and see that there are 3 ways to represent the states on this basis, the index format, the Fock space format, and the integer format. If I access the states in integer or index format and then multiply by the scalars of the linear combination I clearly would not get the desired result, and when I use Fock states it interprets "2|001>" for instance, as "|001>|001>", and float numbers do not make sense. I wonder if it is possible to create a basis where the states are linear combinations with known scalars of the old basis states, and if so, what would be the recommended way of doing it? Thanks! Continue reading...
