[CP2K-user] Constrained DFT (CDFT) Errors

[Nico Holmberg]

Hi Brian,

I am glad to hear that switching to OT resolved your issue. The definitions 
for the terms you asked about are the following


   - Charge transfer energy (J-I): This is the (vertical) energy difference 
   between the two CDFT states. You can compute the solvent reorganization 
   energy and the reaction (free) energy terms from this quantity, which both 
   appear in Marcus theory. In practice, you would need to sample this 
   quantity over a CDFT MD simulation, see e.g. the first CP2K CDFT 
   implementation paper. 
   - Diabatic electronic coupling: This is the effective coupling between 
   the CDFT states after orthogonalization, i.e., the term you would use for 
   H_ab in Marcus' rate equation for ET (see e.g. the CP2K CDFT tutorial for 
   the actual equation).
   - Overlap between states: This is the value of the overlap integral 
   between CDFT states, which are represented by Kohn-Sham Slater determinants 
   (not true wavefunctions). This quantity is needed to compute the electronic 
   coupling, see the CP2K CDFT tutorial for the relevant equations. This 
   quantity measures how similar (value close to 1) or dissimilar (close to 0) 
   the involved CDFT states are.


BR,
Nico  

tiistai 6. marraskuuta 2018 0.03.04 UTC+2 Brian Day kirjoitti:
>
> Hi Nico,
>
> I'm pleased to report that after switching to OT, the only warning that 
> remains is  *** WARNING in pw/pw_pool_types.F:470 :: hit max_cache ***.
>
> If you wouldn't mind answering one last question regarding the output, 
> that would be appreciated. Specifically, what are the differences between 
> "Overlap between states I and J", "Charge transfer energy (J-I)", and 
> "Diabatic electronic coupling" as listed below. I'm am running these 
> calculations to calculate electron transfer rates using Marcus Theory, so 
> presumably I should use the electronic coupling value, but wanted to check. 
>
>   ------------------------- CDFT coupling information 
> --------------------------
>
>   Information at step (fs):                                               
>   0.00
>
>
>   ############################################
>
>   ###### CDFT states I =  1 and J =   2 ######
>
>   ############################################
>
>   Atomic group:                                                          
>       1
>
>   Strength of constraint I:                                      
> -0.254713549611
>
>   Strength of constraint J:                                      
> -0.256763104414
>
>   Final value of constraint I:                                  
> 119.000059959930
>
>   Final value of constraint J:                                  
> 119.000008498861
>
>
>   Overlap between states I and J:                                 
> 0.069002784505
>
>   Charge transfer energy (J-I) (Hartree):                         
> 0.001330331665
>
>
>   Diabatic electronic coupling (Lowdin, mHartree):               
> 19.740562532228
>
>   
> ------------------------------------------------------------------------------
>
>  NO FORCE_EVAL section calculated the dipole
>
>
>  ENERGY| Total FORCE_EVAL ( MIXED ) energy (a.u.):          
> -512.280992021731890
>
>
> Thanks!
>
> -Brian
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20181106/f8b1007b/attachment.htm>