Multiplicity Factor from KPOINTS
Posted: Tue Mar 29, 2022 12:21 pm
Dear Vasp Users,
I am trying to calculate the DOS effective mass from the effective mass tensor, which is defined as
with m_i being the eigenvalues of the effective mass tensor and M the multiplicity respectively.
While I manage to calculate the effective mass tensor, I am not quite sure how I can obtain the multiplicity factor M. For a given k-point, let's say L-point, it should state the number of equivalent k-points to that point of interest, or to rephrase it: How many L-points are there.
As vasp already provides the weights in the KPOINTS file, I thought I could maybe use that to avoid thinking too much about how one would get this number from the unit cell itself. However, I am not sure how to read/reformat the KPOINTs file:
This is a KPOINTS file for PbSe:
If I am interested at the L-point at 0.5/0.5/0.5,
how would I find the multipicity? This point is not in KPOINTS explicitly, so how do I find which point in the list is equivalent to 0.5/0.5/0.5? ( I removed most points in the list above to shorten the text).
Thanks a lot and all the best,
Carl-Friedrich
I am trying to calculate the DOS effective mass from the effective mass tensor, which is defined as
Code: Select all
m*_DOS=M^(3/2) x (m_1 x m_2 x m_3)^(1/3)While I manage to calculate the effective mass tensor, I am not quite sure how I can obtain the multiplicity factor M. For a given k-point, let's say L-point, it should state the number of equivalent k-points to that point of interest, or to rephrase it: How many L-points are there.
As vasp already provides the weights in the KPOINTS file, I thought I could maybe use that to avoid thinking too much about how one would get this number from the unit cell itself. However, I am not sure how to read/reformat the KPOINTs file:
This is a KPOINTS file for PbSe:
Code: Select all
Automatically generated mesh
826
Reciprocal lattice
0.00000000000000 0.00000000000000 0.00000000000000 1
0.04166666666667 0.00000000000000 -0.00000000000000 8
0.08333333333333 -0.00000000000000 0.00000000000000 8
0.12500000000000 -0.00000000000000 -0.00000000000000 8
0.16666666666667 -0.00000000000000 -0.00000000000000 8
0.20833333333333 -0.00000000000000 -0.00000000000000 8
0.25000000000000 -0.00000000000000 -0.00000000000000 8
0.29166666666667 0.00000000000000 -0.00000000000000 8
0.33333333333333 -0.00000000000000 0.00000000000000 8
0.37500000000000 -0.00000000000000 -0.00000000000000 8
0.41666666666667 -0.00000000000000 -0.00000000000000 8
0.45833333333333 -0.00000000000000 -0.00000000000000 8
0.50000000000000 -0.00000000000000 -0.00000000000000 4
0.04166666666667 0.04166666666667 -0.00000000000000 6
0.08333333333333 0.04166666666667 0.00000000000000 24
0.12500000000000 0.04166666666667 -0.00000000000000 24
...
-0.29166666666667 0.45833333333333 0.20833333333333 48
-0.25000000000000 0.45833333333333 0.20833333333333 24
-0.29166666666667 0.50000000000000 0.20833333333333 12how would I find the multipicity? This point is not in KPOINTS explicitly, so how do I find which point in the list is equivalent to 0.5/0.5/0.5? ( I removed most points in the list above to shorten the text).
Thanks a lot and all the best,
Carl-Friedrich