Hi,

I am trying to time evolution of a wave-packet using MPO time evolution, with multi-Hubbard Hamiltonian, which has four operator terms.

ampo +=Jh,"Cdagdn",b,"Cdagup",b,"Cup",b+1,"Cdn",b+1;

ampo +=Jh,"Cdagdn",b+1,"Cdagup",b+1,"Cup",b,"Cdn",b;

Where, I found the problem with "auto expH = toExpH(ampo,tau*Cplx_i);;"

while running it's give error:

From line 1490, file mps/autompo.cc

Only at most 2-operator terms allowed for AutoMPO conversion to MPO/IQMPO

Only at most 2-operator terms allowed for AutoMPO conversion to MPO/IQMPO

Aborted (core dumped)

Please help me to solve this issue.