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forum:data:2020:stranger_things [2020/01/07 18:57] – Created from the form at forum:start Riccardo Piomboforum:data:2020:stranger_things [2025/11/20 03:30] (current) – external edit 127.0.0.1
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-====== STRANGER THINGS ======+====== Wrong (missing) ground state Part 2 ======
 ;;# ;;#
 asked by [[mailto:riccardo.piombo@gmail.com|Riccardo Piombo]] (2020/01/07 18:57) asked by [[mailto:riccardo.piombo@gmail.com|Riccardo Piombo]] (2020/01/07 18:57)
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 <WRAP center box 100%> <WRAP center box 100%>
 Hi every one,  Hi every one, 
-I wrote a simple code to calculate the chemical potential for the addition and for the removal of a particle. The system under consideration is a planar D4h structure composed by a transition metal surrounded by 4 non metal ligands. The problem is the following: when computing the ground state of the N-1 system Quanty seems to output ciclycally three different value for the GS energy which differ from one another by 1.6 eV while for the N and N+1 case it doesn't change (as it must be!). Here is the code could someone copy and paste it on his pc and just run it too check this strange thing!?+I wrote a simple code to calculate the chemical potential for the addition and for the removal of a particle. The system under consideration is a planar D4h structure composed of a transition metal surrounded by 4 non-metal ligands. The problem is the following: when computing the ground state of the N-1 system Quanty seems to output cyclically three different value for the GS energy which differs by almost 1.6 eV in the extreme case while for the N and N+1 case it doesn't change (as it must be!). Here is the code could someone copy and paste it on his pc and just run it too check this strange thing!?
  
 ---------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------
-"Verbosity(0)+<code> 
 + 
 +Verbosity(0)
  
 NF=20 NF=20
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 TdLb1g = 2.6     TdLb1g = 2.6    
  
--- Racah parameters [1]+-- Racah parameters 
 B = 0.09 B = 0.09
 C = 0.54 C = 0.54
  
 -- Slater-Koster integrals for monopole and  -- Slater-Koster integrals for monopole and 
--- multipole part of Coulomb interaction [2]+-- multipole part of Coulomb interaction 
 F2dd = 49.0*B + 7*C F2dd = 49.0*B + 7*C
 F4dd = 441.0*C/35.0 F4dd = 441.0*C/35.0
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 print("") print("")
 print("N-body states energies computation") print("N-body states energies computation")
-Npsi_i = 2+Npsi_i = 1
 StartRestrictions1 = {NF, NB, {"1111111111 0000000000",n4d,n4d}, {"0000000000 1111111111",nL,nL}} StartRestrictions1 = {NF, NB, {"1111111111 0000000000",n4d,n4d}, {"0000000000 1111111111",nL,nL}}
 psiList_N = Eigensystem(H_tot, StartRestrictions1, Npsi_i) psiList_N = Eigensystem(H_tot, StartRestrictions1, Npsi_i)
---psiList_N = {psiList_N}+psiList_N = {psiList_N}
 print("Done") print("Done")
  
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 -- chemical potential μ- to remove a particle -- chemical potential μ- to remove a particle
 +-- ###########################################################
 +-- THE PROBLEM SEEMS TO BE HERE
 print("") print("")
 print("(N-1)-body states energies computation") print("(N-1)-body states energies computation")
-StartRestrictions_rem = {NF, NB, {"1111111111 0000000000",n4d-1,n4d-1}, {"0000000000 1111111111",nL,nL}}+StartRestrictions_rem = {NF, NB, {"1111111111 0000000000",8,8}, {"0000000000 1111111111",10,10}}
 psiList_Nminus1 = Eigensystem(H_tot, StartRestrictions_rem, 1) psiList_Nminus1 = Eigensystem(H_tot, StartRestrictions_rem, 1)
 psiList_Nminus1 = {psiList_Nminus1} psiList_Nminus1 = {psiList_Nminus1}
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 print("μ- = ", remove_mu) print("μ- = ", remove_mu)
 print("") print("")
 +-- ###########################################################
  
 -- chemical potential μ+ to add a particle -- chemical potential μ+ to add a particle
 print("(N+1)-body states energies computation") print("(N+1)-body states energies computation")
-StartRestrictions_add = {NF, NB, {"1111111111 0000000000",n4d+1,n4d+1}, {"0000000000 1111111111",nL,nL}}+StartRestrictions_add = {NF, NB, {"1111111111 0000000000",10,10}, {"0000000000 1111111111",10,10}}
 psiList_Nplus1 = Eigensystem(H_tot, StartRestrictions_add, 1) psiList_Nplus1 = Eigensystem(H_tot, StartRestrictions_add, 1)
 psiList_Nplus1 = {psiList_Nplus1} psiList_Nplus1 = {psiList_Nplus1}
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 mean_mu = (add_mu + remove_mu)/2.0 mean_mu = (add_mu + remove_mu)/2.0
 print("mean μ = [(μ+) + (μ-)]/2 = ", mean_mu) print("mean μ = [(μ+) + (μ-)]/2 = ", mean_mu)
-"+ 
 +</code> 
 + 
 +P.S: after some simulations, the problem seems to appear only when n4d-1 is equal to 8 
 +the GS energy becomes -15.628822671742, -14.433720341628 or -14.042673360744  
 </WRAP> </WRAP>
  
 ~~DISCUSSION|Answers~~ ~~DISCUSSION|Answers~~
  

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