Hi,

I am trying to calculate the magnetic susceptibility at different temperatures for two coupled dimers (similar to a part of tutorial ED-06) using exact diagonalisation. I have been previously using a code called PHI (http://www.nfchilton.com/phi) and an in-house code that can also perform exact diagonalisation. The result I obtain from both the in-house code and PHI are the same but they are different from the ones that I obtain from ALPS using the same parameters. I am not sure why that is the case. The input parameters and the output obtained are in the attached files. For the Zeeman term, I assumed that h is the product of h and g but I have calculated the susceptibility at both h=0.1 and h=0.202 (assuming g=2.02) with ALPS.

Can you please guide me as to what am I doing wrong?

Best regards, Swetanshu.