[CP2K-user] M vector for dielectric constant calculation in CP2K

[Nt]

Dear all:

I have posted here about this problem and have so far not received any 
replies, but am trying again in case there's anyone out there who has dealt 
with static dielectric constant/relative permittivity calculations in CP2K.

I have been struggling for some time with calculating a reasonable static 
dielectric constant for water at 20 C and atmospheric pressure.  So far I 
calculate values of <1 where I should be getting ~80 (for both Quickstep 
and FIST-based CP2K simulations) so there is probably something basic I 
don't understand about how to deal with the CP2K output.  

I want to use the expression attached.  It is likely my problem is related 
to the M term, which I need to calculate from CP2K output.  Here is a small 
snippet from a "moments.traj" output file (below).  My understanding is 
that there are three time steps represented here.  I extract the "Debye" 
lines and use those to calculate a total dipole moment by taking the square 
root of the sum of the squares of the three components in a "Debye" row.  I 
then convert everything to SI units.  

 MM DIPOLE [BERRY PHASE](A.U.)|                  -3.333675   0.611131   
1.550260
 MM DIPOLE [BERRY PHASE](Debye)|                 -8.473356   1.553341   
3.940367
 MM DIPOLE [BERRY PHASE] DERIVATIVE(A.U.)|        0.000767  -0.000211   
0.001268
 MM DIPOLE [BERRY PHASE](A.U.)|                  -3.600074   0.921496   
1.793125
 MM DIPOLE [BERRY PHASE](Debye)|                 -9.150475   2.342208   
4.557669
 MM DIPOLE [BERRY PHASE] DERIVATIVE(A.U.)|        0.000754  -0.000212   
0.001278
 MM DIPOLE [BERRY PHASE](A.U.)|                  -3.593577   0.947832   
1.795335
 MM DIPOLE [BERRY PHASE](Debye)|                 -9.133960   2.409149   
4.563287
 MM DIPOLE [BERRY PHASE] DERIVATIVE(A.U.)|        0.001552  -0.000548   
0.000455


There is a CP2K tutorial that calculates the dielectric constant at this 
link:

https://www.cp2k.org/exercises:2017_ethz_mmm:monte_carlo_ice

I think my method for calculating M is the same as in the tutorial's 
"calc_dielectric_constant.py" example.  I have tried running the example to 
check that the format of its moments output file is the same as what I'm 
using (I can't tell from the Python code).  I am still trying, but so far 
haven't been able to run it successfully.  

The example uses a different expression than I am as far as calculating the 
dielectric constant and I have tried it as well as my expression.  Neither 
results in a value ~80.  

If anyone can provide any information/resources on calculating the M term 
or on another code I can use to process my existing CP2K output to check my 
methods, I would be very grateful.  Thank you.
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