Allen Wang

Hi Matthew, Sure, just don't feel stressed about this. I thought I've already found a way to avoid this problem (at the physical level). With my special boundary condition the \sigma_1^z and \sigma_L^z are conserved, so I could just manually implement these conserved quantities by doing simulation on a smaller system with L-2 sites, where there is a h\sigma^z term on the first and last spin. The original ground states correspond to h=J_z, h'=J_z and h=-J_z, h'=-J_z, while the original lowest excited...

Hi Matthew, When I set 'n_excited_states' to be 1 and local_tol to be 1E-30, it runs OK: -58.6081057073068 True -58.6081057073072 True Notice that these are actually the two ground states (with exact degeneracy guaranteed by the quaternion symmetry). When I set 'n_excited_states' to be 2 and local_tol to be 1E-12, then the 2nd excited state gives an error: Tensors_include.f90:894: dot_tensor: dimension mismatch. Note: The following floating-point exceptions are signalling: IEEE_UNDERFLOW_FLAG IEEE_DENORMAL...

Hi Matthew, Where is the fix?

Hi Matthew, I'm happy to see you've got a fix. I'm not in a hurry, fixing it by tomorrow is totally fine, so please take your time. Just reminding you so that you don't totally forget this. Thanks in advance.

Hi Matthew, May I ask if you have figured out how to solve this issue? I'm still very interested in this as I'm using this code for a research project. Any suggestions for me? Even a temporary solution would be fine (e.g. would using a different computer work?), as I don't plan to do large scale numerics. I'm just using numerics to compare with my analytic results. Thanks.

Hi Matthew, I recompiled openmps again, did exactly what you said, including the -O0 flag, but the error still exists. This time it says: Beginning eMPS for convergence parameter set/state: 1 2 ! Beginning two-site excited state. outer 1 sweep 1 bd 21 energy 0.0000000000000000 Site k, energy 1 -76.803053762636139 Site k, energy 2 -81.089303202367773 Site k, energy 3 -86.930343031361673 Site k, energy 4 -89.754093300675052 Site k, energy 5 -94.172753591469061 Site k, energy 6 -94.768090196263969 16...

Hi, I just tried the newest OpenMPS3.1 version but the problem remains, it says: On entry to DGEMM parameter number 10 had an illegal value Note: The following floating-point exceptions are signalling: IEEE_UNDERFLOW_FLAG IEEE_DENORMAL. Daniel, what do you mean by adding "-O0" flag? Do you mean when I install openmps I should type python BuildOSMPS.py -O0 --local='./' ?

Hi Matthew, I'm using OpenMPS v3.0 which I installed about a year ago. I think I just followed the html documentation. My system is ubuntu 18.04. I just noticed there is a newer version v3.1. Maybe I should download the newer version and try again with the same code. [Also, the illegal value error doesn't always occur, it depends on the values of parameters Jx, Jy,Jz. But I met the error at several different points.]