Why cannot I convert this ITensor to an Array{Float64}

ITensor Julia Questions
1

I am trying to convert a specific ITensor to an Array{Float64,4} as part of the following code

using Serialization, ITensors
using TensorOperations
include("ccd-helper.jl")
initialize_cc_variables()
begin
a_1 = Index(2,"a_1")
a_2 = Index(2,"a_2")
i_1 = Index(4,"i_1")
i_2 = Index(4,"i_2")
end
begin
iT2 = ITensor(T2,a_1,a_2,i_1,i_2)
iR2 = ITensor(R2,a_1,a_2,i_1,i_2)
iScaled_R2 = ITensor(Scaled_R2,a_1,a_2,i_1,i_2)
end

for i in 1:25
    aT2 = Array(iT2,a_1,a_2,i_1,i_2)
    serialize("T2_vvoo.jlbin",aT2)
    iR2 = calculate_residual_memeff()
    iT2 = update_T2(iT2,iR2,iScaled_R2)
    # @show iR2
end
Array(iR2,a_1,a_2,i_1,i_2)

where T2 R2 and Scaled_R2 are all of type Array{Float64,4}. Running the above code results in the error

ERROR: BoundsError: attempt to access NTuple{4, Index{Int64}} at index [0]
Stacktrace:
  [1] getindex
    @ ./tuple.jl:31 [inlined]
  [2] #7
    @ ~/.julia/packages/ITensors/2Xz5q/src/NDTensors/tupletools.jl:43 [inlined]
  [3] macro expansion
    @ ./ntuple.jl:72 [inlined]
  [4] ntuple
    @ ./ntuple.jl:69 [inlined]
  [5] _permute
    @ ~/.julia/packages/ITensors/2Xz5q/src/NDTensors/tupletools.jl:43 [inlined]
  [6] permute
    @ ~/.julia/packages/ITensors/2Xz5q/src/NDTensors/tupletools.jl:50 [inlined]
  [7] permutedims
    @ ~/.julia/packages/ITensors/2Xz5q/src/NDTensors/dense.jl:373 [inlined]
  [8] permutedims
    @ ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:1613 [inlined]
  [9] _permute(as::ITensors.NDTensors.NeverAlias, T::ITensors.NDTensors.DenseTensor{…}, new_inds::NTuple{…})
    @ ITensors ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:1618
 [10] permute(as::ITensors.NDTensors.NeverAlias, T::ITensor, new_inds::NTuple{4, Index{Int64}})
    @ ITensors ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:1622
 [11] permute
    @ ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:1627 [inlined]
 [12] #permute#214
    @ ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:1603 [inlined]
 [13] permute
    @ ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:1592 [inlined]
 [14] Array{Float64, 4}(::ITensor, ::Index{Int64}, ::Index{Int64}, ::Index{Int64}, ::Index{Int64})
    @ ITensors ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:771
 [15] Array(::ITensor, ::Index{Int64}, ::Index{Int64}, ::Index{Int64}, ::Index{Int64})
    @ ITensors ~/.julia/packages/ITensors/2Xz5q/src/itensor.jl:780
 [16] top-level scope
    @ ~/Desktop/Andreas/phase_2/julia-code/ccd/itensors/t5.jl:52
Some type information was truncated. Use `show(err)` to see complete types.

Whereas doing Array(iR2,a_1,a_2,i_1,i_2) gives the expected correct result. I understand that this might be due to what is happening inside the function calculate_residual_memeff(). The function definition is given below

calculate_residual_memeff() 
function calculate_residual_memeff()
    nocc = deserialize("nocc.jlbin")
    nv = deserialize("nv.jlbin")
    i_1= Index(nocc, "i_1")
    i_2= Index(nocc, "i_2")
    i_3= Index(nocc, "i_3")
    i_4= Index(nocc, "i_4")
    a_1= Index(nv, "a_1")
    a_2= Index(nv, "a_2")
    a_3= Index(nv, "a_3")
    a_4= Index(nv, "a_4")
    I_vvoo = ITensor(zeros(Float64, nv, nv, nocc, nocc), a_1, a_2, i_1, i_2) #create function generated this line
    g_voov = ITensor(deserialize("g_voov.jlbin"),a_1, i_3, i_1, a_3)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_3, i_3, i_2)
    
    I_vvoo += -1*g_voov*T2_vvoo
    #Unload T2_vvoo
    #Unload g_voov
    g_vvoo = ITensor(deserialize("g_vvoo.jlbin"),a_1, a_2, i_1, i_2)
    
    I_vvoo += 1/2*g_vvoo
    #Unload g_vvoo
    g_vovo = ITensor(deserialize("g_vovo.jlbin"),a_2, i_3, a_3, i_2)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_1, i_3)
    
    I_vvoo += -1*g_vovo*T2_vvoo
    #Unload T2_vvoo
    #Unload g_vovo
    g_vovo = ITensor(deserialize("g_vovo.jlbin"),a_2, i_3, a_3, i_1)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_3, i_2)
    
    I_vvoo += -1*g_vovo*T2_vvoo                                                                 #fourth update
    # @show I_vvoo
    #Unload T2_vvoo
    #Unload g_vovo
    g_voov = ITensor(deserialize("g_voov.jlbin"),a_1, i_3, i_1, a_3)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_3, i_2, i_3)
    
    I_vvoo += 2*g_voov*T2_vvoo
    #Unload T2_vvoo
    #Unload g_voov
    g_oooo = ITensor(deserialize("g_oooo.jlbin"),i_3, i_4, i_1, i_2)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_2, i_3, i_4)
    
    I_vvoo += 1/2*g_oooo*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oooo
    f_vv = ITensor(deserialize("f_vv.jlbin"),a_2, a_3)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_1, i_2)
    
    I_vvoo += f_vv*T2_vvoo
    #Unload T2_vvoo
    #Unload f_vv
    g_vvvv = ITensor(deserialize("g_vvvv.jlbin"),a_1, a_2, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_3, a_4, i_1, i_2)
    
    I_vvoo += 1/2*g_vvvv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_vvvv
    f_oo = ITensor(deserialize("f_oo.jlbin"),i_3, i_2)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_2, i_1, i_3)
    
    I_vvoo += -1*f_oo*T2_vvoo
    #Unload T2_vvoo
    #Unload f_oo
    I_ovov = ITensor(zeros(Float64, nocc, nv, nocc, nv), i_4, a_1, i_1, a_4) #create function generated this line
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_1, i_3)
    
    I_ovov += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_4, i_2, i_4)
    
    I_vvoo += 2*I_ovov*T2_vvoo                              #10th update
    # @show I_vvoo
    #Unload T2_vvoo
    #Unload I_ovov
    I_ovov = ITensor(zeros(Float64, nocc, nv, nocc, nv), i_4, a_1, i_1, a_4)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_1, i_3)
    
    I_ovov += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_4, i_4, i_2)
    
    I_vvoo += -2*I_ovov*T2_vvoo
    #Unload T2_vvoo
    #Unload I_ovov
    I_ovov = ITensor(zeros(Float64, nocc, nv, nocc, nv), i_4, a_1, i_1, a_4)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_3, i_1)
    
    I_ovov += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_4, i_4, i_2)
    
    I_vvoo += 1/2*I_ovov*T2_vvoo
    #Unload T2_vvoo
    #Unload I_ovov
    I_oo = ITensor(zeros(Float64, nocc, nocc), i_4, i_2) #create function generated this line
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_3, a_4, i_3, i_2)
    
    I_oo += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_2, i_1, i_4)
    
    I_vvoo += -2*I_oo*T2_vvoo
    #Unload T2_vvoo
    #Unload I_oo
    I_ovov = ITensor(zeros(Float64, nocc, nv, nocc, nv), i_4, a_1, i_1, a_3)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_4, i_1, i_3)
    
    I_ovov += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_3, i_2, i_4)
    
    I_vvoo += -1*I_ovov*T2_vvoo
    #Unload T2_vvoo
    #Unload I_ovov
    I_ovov = ITensor(zeros(Float64, nocc, nv, nocc, nv), i_4, a_1, i_1, a_3)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_4, i_1, i_3)
    
    I_ovov += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_3, i_4, i_2)
    
    I_vvoo += I_ovov*T2_vvoo                #15th update
    
    
    
    
    
    
    
    
    
    
    # @show I_vvoo   #15th update obdi shob same asche
    #Unload T2_vvoo  
    #Unload I_ovov
    I_vv = ITensor(zeros(Float64, nv, nv), a_2, a_3) #create function generated this line
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_4, i_4, i_3)
    
    I_vv += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_3, i_1, i_2)
    
    I_vvoo += I_vv*T2_vvoo
    #Unload T2_vvoo
    #Unload I_vv
    I_oo = ITensor(zeros(Float64, nocc, nocc), i_4, i_2)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_3, a_4, i_2, i_3)
    
    I_oo += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_2, i_1, i_4)
    
    I_vvoo += I_oo*T2_vvoo
    #Unload T2_vvoo
    #Unload I_oo
    I_vv = ITensor(zeros(Float64, nv, nv), a_2, a_4)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_3, i_4, i_3)
    
    I_vv += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_4, i_1, i_2)
    
    I_vvoo += -2*I_vv*T2_vvoo  #18th update
    # @show I_vvoo                     #Till here everything matches
    
    
    
    
    
    
    
    
    
    
    
    #Unload T2_vvoo
    #Unload I_vv
    I_ovov = ITensor(zeros(Float64, nocc, nv, nocc, nv), i_4, a_1, i_2, a_3)#Load and set to zero julia equivalent
    
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4)
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_4, i_3, i_2)
    
    I_ovov += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_2, a_3, i_4, i_1)    
    I_vvoo += 1/2*I_ovov*T2_vvoo
    #Unload T2_vvoo
    #Unload I_ovov
    I_oooo = ITensor(zeros(Float64, nocc, nocc, nocc, nocc), i_3, i_4, i_1, i_2) #create function generated this line
    g_oovv = ITensor(deserialize("g_oovv.jlbin"),i_3, i_4, a_3, a_4
    
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_3, a_4, i_1, i_2)
    I_oooo += g_oovv*T2_vvoo
    #Unload T2_vvoo
    #Unload g_oovv
    T2_vvoo = ITensor(deserialize("T2_vvoo.jlbin"),a_1, a_2, i_3, i_4)
    I_vvoo += 1/2*I_oooo*T2_vvoo               #20th update
    R2 = ITensor(zeros(Float64,nv,nv,nocc,nocc),a_1,a_2,i_1,i_2)
    R2 += I_vvoo + swapinds(I_vvoo,(a_1,i_1),(a_2,i_2)) #correct symmetrization
    return R2
end
2

I don’t know what is going on in your code, but this minimal example works for me:

julia> using ITensors

julia> using ITensors: Index, random_itensor

julia> i, j = Index.((2, 2))
((dim=2|id=781), (dim=2|id=473))

julia> a = random_itensor(i, j)
ITensor ord=2 (dim=2|id=781) (dim=2|id=473)
NDTensors.Dense{Float64, Vector{Float64}}

julia> Array(a, i, j)
2×2 Matrix{Float64}:
 0.744929  0.220073
 1.5734    0.112152
1 Like
3

Trying to construct your own minimal examples like that may be instructive for you, you have been raising a lot of issues that appear to be code snippets from a more complicated code. Breaking up the problem into smaller parts and writing simple example codes on the side that are independent from the rest of your code that try to reproduce issues you think you are seeing may help you debug more yourself, and also if you find what you think is an issue those simpler codes would be more helpful to share with us rather than parts of a more complicated code.