- #1

bumblebee77

- 56

- 2

- TL;DR Summary
- I have Berry phase dipole moments over time from a simulation but don't understand how to correct the jumps in the data.

Is there anyone out there who can help a newbie understand how to deal with Berry phase dipole moment data?

I ran a simulation to calculate dipole moments over time using the Berry phase method. The problem is that there are jumps in my data. There is an example at the end of this post (part of the z component data), where one row (time step) is +23.x and the next row is -23.x.

For each dipole moment (row), I have this:

Dipole vectors are modulo integer multiples of the cell matrix.

I ran a simulation to calculate dipole moments over time using the Berry phase method. The problem is that there are jumps in my data. There is an example at the end of this post (part of the z component data), where one row (time step) is +23.x and the next row is -23.x.

For each dipole moment (row), I have this:

Dipole vectors are modulo integer multiples of the cell matrix.

*[X] [ 45.8125 0.0000 0.0000 ] [i ]*

*[Y]=[ 0.0000 45.8125 0.0000 ]*[j]*

[Z] [ 0.0000 0.0000 45.8125 ] [k]

I think what is going on is that in the Berry Phase, the dipole moment is not an absolute value. It is tied to the cell matrix. So when a dipole moment component exceeds the value in the cell matrix (45.8125 in my example), then it shows up in my output as some number that represents 45.8125 --> reset to 0--> add whatever is left.

Could someone please let me know if I am on the right track? I am trying to figure out how to correct my output dipole moment data to get a time series that I can use in a calculation. If anyone knows how to do that and could explain or point me to an online resource, I would be very appreciative.

22.11478446

22.33207588

23.86209392

-23.4624732

-23.04423182

-22.6735481

-22.36681344

-22.13680091

-21.99437418

-21.94794955

-22.00093276

-22.14894473

-22.37851464

-22.98852983

-23.30787693

-23.59047008

-23.80075739

23.86218945

-23.88415599

-23.72229234

-23.42677872

-23.02231253

-22.55223629

-22.07417372

-21.65136982

-21.34266766

-21.19465513[Z] [ 0.0000 0.0000 45.8125 ] [k]

I think what is going on is that in the Berry Phase, the dipole moment is not an absolute value. It is tied to the cell matrix. So when a dipole moment component exceeds the value in the cell matrix (45.8125 in my example), then it shows up in my output as some number that represents 45.8125 --> reset to 0--> add whatever is left.

Could someone please let me know if I am on the right track? I am trying to figure out how to correct my output dipole moment data to get a time series that I can use in a calculation. If anyone knows how to do that and could explain or point me to an online resource, I would be very appreciative.

22.11478446

22.33207588

23.86209392

-23.4624732

-23.04423182

-22.6735481

-22.36681344

-22.13680091

-21.99437418

-21.94794955

-22.00093276

-22.14894473

-22.37851464

-22.98852983

-23.30787693

-23.59047008

-23.80075739

23.86218945

-23.88415599

-23.72229234

-23.42677872

-23.02231253

-22.55223629

-22.07417372

-21.65136982

-21.34266766

-21.19465513