The ABINIT Users Mailing List ( CLOSED )

[hongki@physics.utexas.edu]

Hello all,

Someone asked me to clarify my question so I'm sending this e-mail.
What I want to change is the direction of the net magnetization.
Let R be the direction of the magnetization and |n> be a ket vector,
then Berry connection A(R) is given by A(R)=i<n(R)|grad.|n(R)>
By changing R, Berry curvature and Chern number can be calculated at all R.
Here the variable for the derivative is R(net magnetization) rather than k
or other variable and this direction need not be that of the minimum energy.

I hope this clarifies my question and any help would be appreciated.
Hongki Min

Original Question--------------------------
Hello everyone,
I'm trying to calculate Berry curvature and Chern number changing net 
magnetization.
In this forum, there is explanation about Berry phase approach to 
polarization 
including derivatives of wavefunctions with respect to k or other variables.
However, what I want to change is the direction of the net magnetic moment so 
that by calculating Berry curvature along the arbitary direction of the 
magnetic
moment,which in general need not be the lowest energy direction, and 
averaging it, 
I want to calculate the Chern number.