Zero-field splitting

Warning

Work in progress

This tutorial calculates the zero-field splitting for the NV center in diamond and bi-radicals.

gpaw.zero_field_splitting.zfs(calc, method=1)

Zero-field splitting.

Calculate magnetic dipole coupling tensor in eV.

gpaw.zero_field_splitting.convert_tensor(D_vv, unit='eV')

Convert 3x3 tensor to D, E and easy axis.

Input tensor must be in eV and the result can be returned in eV, μeV, MHz or 1/cm according to the value of unit (must be one of “eV”, “ueV”, “MHz”, “1/cm”).

>>> D_vv = np.diag([1, 2, 3])
>>> D, E, axis, _ = convert_tensor(D_vv)
>>> D
4.5
>>> E
0.5
>>> axis
array([0., 0., 1.])

Examples

Diamond NV- center

For a NV center in a cubic supercell, the D and E values are presented below with and without relaxaing the cell. The experimental value is around 2880 MHz.

atoms	relaxed	D (MHz)	E(MHz)
62	False	2466	4.03e-11
62	True	1712	2.10e-09
214	False	2516	8.37e-05
214	True	1867	4.13e-05

diamond_nv_minus.py.

Bi-radical

biradical.py. plot.py.