Unit of DFT energy calculation

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I am trying to calculate energy of hydrogen bond, based on bond length, using b3lyp xc and aug-cc-pvdz basis set. All I am getting as my DFT energy is like(for bond length 2.5 angstrom):

           Total DFT energy =      -75.580432010766
      One electron energy =     -105.872820803882
           Coulomb energy =       37.948128899715
    Exchange-Corr. energy =       -8.772184258729
 Nuclear repulsion energy =        1.116444152131
 Numeric. integr. density =        8.999998951783
     Total iterative time =      1.6s

Now I am not being able to find out that what actually is the unit of Total DFT energy and all other parameters.

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Hi Neo,

All energies in the ab-initio capabilities are reported in Hartree (or equivalently atomic units) unless stated otherwise. See for example http://www.ucl.ac.uk/~uccaati/Energy.html for conversion factors.


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start oh-dat
 geometry noautoz units angstrom
   symmetry c1
     o  -1.874  24.116  62.689   
     h   0.878  22.906  65.000
   * library aug-cc-pvdz
   mult 4  
   xc b3lyp
 task dft energy

i am using this above code to calculate.. but if the output DFT energy is in Hartees then sure there must be a serious error in my code. Because no way hydrogen bond be that strong as 75 Hartee or 47100kcal/mol.
Any comment regarding this issue would be very helpful.
thank you.

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basically you're not generating the bond energy here, well you are but you also have the energy to put the electrons in all of the other orbitals (the various non bonding orbitals) the best way to get a bond energy is probably to do a scan along the bond and see how the energy changes, it should generate a bond dissossiation curve which you can then use to judge what the bond energy is

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