[DFTB-Plus-User] Total_Energy_vs_total_energy

[keshtan]

Dear Dr. Bálint Aradi,


I truly value your response. I am dealing with another issue. Even 
though my geometry was adjusted by using SIESTA and Gaussian, I was 
unable to determine the optimal geometry for a single molecule junction 
by using the DFTB+. I have included my dftb_in.hsd file. Is there 
anything in it that I defined wrong? My mol.gen file includes the 
geometry of the structure and its unit cell vectors.

I really appreciate your consideration.


Sincerely,

M.A.M.Keshtan
Mohammad Ali Mohammadi Keshtan





On 2025-11-19 09:50, Bálint Aradi wrote:
> Dear Mohammad,
> 
> you compare the wrong items. At finite electronic temperatures, the
> 
> Total Mermin free energy
> 
> is the force relevant energy. Actually, we have extra a
> 
> Force related energy
> 
> in detailed.out, which always contains the energy, from which the
> force is calculated (by taking its negative gradient).
> 
> Best regards,
> 
> Bálint
> 
> 
> On 11/14/25 2:10 PM, keshtan wrote:
>> Dear All,
>> 
>> 
>> In the "detailed.out" output file, what is the difference between the 
>> last step "Total Energy", and the "total energy" parameters in 
>> geometry optimization? You can see my last step part below.
>> 
>> 
>> --------------------------------------------------------------------------------
>> 
>> ***  Geometry step: 2656
>> 
>>   iSCC Total electronic   Diff electronic      SCC error
>>      1   -0.13991252E+03    0.00000000E+00    0.96129440E-05
>> 
>> Total Energy:                     -142.3202491328 H        -3872.7310 
>> eV       <<< this parameter>>>
>> Extrapolated to 0K:               -142.3217836687 H        -3872.7728 
>> eV
>> Total Mermin free energy:         -142.3233182046 H        -3872.8145 
>> eV
>> Force related energy:             -142.3233182046 H        -3872.8145 
>> eV
>> 
>>>> Charges saved for restart in charges.dat
>> 
>> total energy  -1.4232332E+02 H       energy change -1.6927970E-10 H    
>>   <<< this parameter>>>
>> gradient norm  1.1891656E-05 H/a0    max. gradient  9.7105670E-06 H/a0
>> step length    1.3495849E-05 a0      max. step      1.0954003E-05 a0
>> 
>> Geometry converged
>> 
>> 
>> I really appreciate your consideration.
>> 
>> 
>> Sincerely,
>> 
>> 
>> M.A.M.Keshtan
>> Mohammad Ali Mohammadi Keshtan
>> _______________________________________________
>> DFTB-Plus-User mailing list
>> DFTB-Plus-User at mailman.zfn.uni-bremen.de
>> https://mailman.zfn.uni-bremen.de/cgi-bin/mailman/listinfo/dftb-plus-user
> 
> 
> _______________________________________________
> DFTB-Plus-User mailing list
> DFTB-Plus-User at mailman.zfn.uni-bremen.de
> https://mailman.zfn.uni-bremen.de/cgi-bin/mailman/listinfo/dftb-plus-user
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: dftb_in.hsd
URL: <http://mailman.zfn.uni-bremen.de/pipermail/dftb-plus-user/attachments/20251119/76f0c5ad/attachment.ksh>