store ground state in h5 file

ITensor Julia Questions
1

Hello,
I have a quick question about saving the ground state I got in a h5 file (I’ve done this before, and I just ran a new calculation and save my ground state in the same way, but got some error currently…)
My code is as below, besically I just give it an initial psi0 and get a psi_tem1, and save it in file f as “PGS”.

energy, psi_tem1 = dmrg(H, psi0, sweeps_tem)
f = h5open("mu$(mu)U$(U)V$(V)_$(N)sites—tem.h5","w")
write(f,"PGS",psi_tem1)
close(f)
println("finish 3tem sweeps in total")

But then when I try to read it as below:

f = h5open("mu$(mu)U$(U)V$(V)_$(N)sites—tem.h5","w")
psi_tem1 = read(f,"PGS",MPS)
close(f)
psi_tem1 = replace_siteinds(psi_tem1,sites)

The error message says “PGS” doesn’t exist.
Could you help to see why this happen? Thank you so much!

(The whole error message:)
HDF5-DIAG: Error detected in HDF5 (1.12.1) thread 1:
#000: H5G.c line 510 in H5Gopen2(): unable to open group
major: Symbol table
minor: Can’t open object
#001: H5VLcallback.c line 4187 in H5VL_group_open(): group open failed
major: Virtual Object Layer
minor: Can’t open object
#002: H5VLcallback.c line 4154 in H5VL__group_open(): group open failed
major: Virtual Object Layer
minor: Can’t open object
#003: H5VLnative_group.c line 123 in H5VL__native_group_open(): unable to open group
major: Symbol table
minor: Can’t open object
#004: H5Gint.c line 270 in H5G__open_name(): group not found
major: Symbol table
minor: Object not found
#005: H5Gloc.c line 442 in H5G_loc_find(): can’t find object
major: Symbol table
minor: Object not found
#006: H5Gtraverse.c line 837 in H5G_traverse(): internal path traversal failed
major: Symbol table
minor: Object not found
#007: H5Gtraverse.c line 613 in H5G__traverse_real(): traversal operator failed
major: Symbol table
minor: Callback failed
#008: H5Gloc.c line 399 in H5G__loc_find_cb(): object ‘PGS’ doesn’t exist
major: Symbol table
minor: Object not found
ERROR: LoadError: Error opening group //PGS

2

Any chance it works if you change "w" to "r" (or “r+” if you want to read/write)? The original data will be probably gone though since "w" = “read-write, destroying any existing contents (if any)”.

Also I recommend doing something like

psi_tem1 = h5open("data.h5", "r") do f
      read(f,"PGS",MPS)
end

this method will always close the file so you can open it again later (but won’t prevent the “w” problem)

3

Thank you! Let me run my code again and try this!