# total dft energy differs from partial energies

 Clicked A Few Times
 4:02:52 AM PST - Fri, Feb 26th 2016 Dear all, i'm facing either very serious lack in my theory background or compilation/nwchem problem. I did several calculations and just recently i noticed very strange thing (i checked three different calculations) - see part of my output below: ``` Total DFT energy = -1144.144378448133 One electron energy = -5654.477100400897 Coulomb energy = 2607.095668751906 Exchange-Corr. energy = -156.929943044225 Nuclear repulsion energy = 2058.598637126281 Numeric. integr. density = 178.000323079243 ``` when you sum all the energies you get different number (?1145.7127...) than the one reported in Total DFT energy. i've got this in all three calculations (probably all of them). Also, the difference in reported and "summed" energy is always different, approximately ~1.2 to 1.7 Hartrees. This is the input corresponding to the upper energies: ```start dimerBO4-MM1c33_GO-B3LYP-321G MEMORY stack 2600 heap 500 global 800 mb title "beta-O4-dimer in ccl4, initial structure from oBabel weighted conf search (MM1) - c33, geometry optimization B3LYP 3-21G" geometry units an print xyz autosym H 1.09605 -2.24257 -1.90815 C 1.41847 -2.08854 -0.87674 C 1.84098 -3.17525 -0.07199 O 1.81819 -4.39938 -0.71640 C 2.26350 -2.93298 1.25811 O 2.79497 -3.97266 1.98226 C 2.10800 -1.64323 1.80510 O 2.33657 -1.45588 3.14564 C 1.74719 -0.58915 0.97642 H 1.73301 0.42869 1.34122 C 1.39752 -0.79060 -0.35917 C 0.90359 0.40502 -1.15331 C -0.54163 0.75608 -0.75684 H -1.16737 -0.14184 -0.68909 O -1.10710 1.65905 -1.73269 H -0.49837 1.18660 0.24421 C -2.06553 2.54149 -1.28458 C -3.01765 3.05298 -2.19910 O -2.94863 2.67755 -3.52330 C -4.00905 3.94736 -1.72167 H -4.75432 4.37610 -2.37384 C -4.06928 4.30063 -0.38461 H -4.84743 4.97387 -0.04043 C -3.11615 3.83955 0.49294 H -3.13149 4.13319 1.53682 C -2.10145 2.99245 0.04157 H -1.34790 2.73593 0.77732 C 1.89481 -0.23345 3.71973 C 3.84170 -3.67014 2.90678 C 1.63138 -5.56450 0.09157 H 0.73470 -5.46345 0.71315 H 1.48749 -6.43465 -0.55333 H 2.51469 -5.79038 0.69721 H 3.54935 -4.04304 3.89421 H 4.75448 -4.18066 2.59112 H 4.12551 -2.61952 2.99152 H 2.32886 0.64722 3.23285 H 0.80152 -0.19671 3.70476 H 2.23703 -0.20924 4.75333 C -3.98692 3.19145 -4.36561 H -4.96530 2.79737 -4.06074 H -3.81279 2.87185 -5.39740 H -3.99778 4.28856 -4.37035 O 1.75905 1.51930 -0.84503 H 1.36853 2.29218 -1.28841 H 0.99887 0.22346 -2.22515 end basis small * library 3-21G end basis large * library 6-31+G* end set "ao basis" small cosmo dielec 2.24 end dft xc b3lyp CONVERGENCE density 1e-8 CONVERGENCE energy 1e-8 GRID lebedev 90 14 ssf euler MAXITER 60 end driver EPREC 1e-8 GRMS 0.000004 MAXITER 900 XYZ geomSteps_r2 end task dft optimize ``` I really hope that i'm missing something. Thank you very much for help.

 Clicked A Few Times
 4:08:14 AM PST - Fri, Feb 26th 2016 i forgot to mention, that i checked results obtained on two different clusters, version 6.6 on both of them, but compiled independently on each other, by different person, with delay of ~6 months.

 Forum Regular
 11:59:05 AM PST - Fri, Feb 26th 2016 The confusion is due to the solute-solvent interaction energy not being written explicitly in the output, i.e. the total energy is correct, you are just missing an energy component in the output. The patch is available at nwchemgit.github.io/download.php?f=Cosmo_dftprint.patch.gz

 Clicked A Few Times
 12:28:31 PM PST - Fri, Feb 26th 2016 that patch is new, right? also, i'm not sure, but in the COSMO part of the output i didn't attach originally is: ``` Total DFT energy = -1144.144378448133 One electron energy = -5654.477100400897 Coulomb energy = 2607.095668751906 Exchange-Corr. energy = -156.929943044225 Nuclear repulsion energy = 2058.598637126281 Numeric. integr. density = 178.000323079243 Total iterative time = 76.1s COSMO solvation results ----------------------- gas phase energy = -1144.1300273697 sol phase energy = -1144.1443784481 (electrostatic) solvation energy = 0.0143510784 ( 9.01 kcal/mol) DFT Final Molecular Orbital Analysis ``` So I would assume that solvation energy is the solute-solvent interaction energy that you mentioned, isn't it? If so, than this energy is much smaller - only 0.01 Hartree, whereas the difference was bigger than 1 Hartree. Of course, I'll apply the patch and try the calculation again.

 Forum Regular
 2:05:36 PM PST - Fri, Feb 26th 2016 Yes, the patch is new, created this morning in response to your post. The listed solvation energy is simply the difference in energy between the gas phase result and the solution phase result and not the solute-solvent interaction energy to which I was referring.

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