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calculate_u-function [2012/11/07 12:12]
vlada
calculate_u-function [2012/11/07 16:57] (current)
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 ===== U - function ===== ===== U - function =====
-This page shows how to calculate U - function to correct the gap of molecules. ​ 
  
 +This page shows how to calculate U - function. ​
 +There is an simple example of calculation U -function for simple CH5N molecule below.
 +Here are input files.
 + 
 +----
 +
 +CH5N.bas ​
 +<​code>​
 +           7
 +   ​7 ​     1.763266 ​     0.773353 ​    ​-0.259722
 +   ​6 ​     0.474220 ​     0.075638 ​    ​-0.015967
 +   ​1 ​     2.595372 ​     0.133817 ​    ​-0.297809
 +   ​1 ​     2.017882 ​     1.470682 ​     0.480907
 +   ​1 ​     0.229708 ​    ​-0.640655 ​    ​-0.836563
 +   ​1 ​    ​-0.382559 ​     0.790390 ​     0.018898
 +   ​1 ​     0.401767 ​    ​-0.518300 ​     0.926463
 +</​code>​
 +Calculation of U-function is turned on by iu = 1 in fireball.in.
 +
 +fireball.in
 +<​code>​
 +&OPTION
 +basisfile = CH5N.bas ​
 +icluster = 1
 +nstepf = 1
 +T_initial = 100.0
 +T_final = 100.0
 +sigmatol = 0.000000001
 +dt = 0.01
 +iquench = 0
 +max_scf_iterations = 200
 +iu = 1 
 +&END
 +
 +&OUTPUT
 +iwrteigen = 1
 +iwrtxyz = 1
 +iwrtefermi = 1
 +&END
 +</​code>​
 +Next you need input file u.inp, where you have to write total number of electron. You can choose molecular orbitals for which you want to calculate U. There are 5 orbitals (6,​7,​8,​10,​22) in this case.
 + u.inp
 +<​code>​
 +14     ! number of electrons
 +5      ! number of orbitals
 +6      ! states number ​
 +7
 +8
 +10
 +22
 +</​code>​
 +The output file is called u_func.dat, where is written number of selected orbital in the first column and in the second one are u values.
 +<​code>​
 +           ​6 ​  ​2.1590 ​    
 +           ​7 ​  ​2.3341 ​    
 +           ​8 ​  ​1.9742 ​    
 +          10   ​1.9721 ​   ​
 +          22   ​1.4045 ​    
 +</​code>​
calculate_u-function.1352286735.txt.gz ยท Last modified: 2012/11/07 12:12 (external edit)