rotational invariance in single atom
Posted: Mon Feb 14, 2011 9:58 pm
Hi,
I have a question regarding numerical accuracy of vasp with broken symmetry ground state of an open-shell, magnetic atom or ion. If initial occupancy of different, physically degenerate orbitals (e.g. with either x^2 or z^2 initially occupied) are specified, the calculated energy should be the same. However, vasp gave me energy differences of a few up to 20 meV. How can I improve the numerical accuracy? I tried ADDGRID=.TRUE. and PREC=Accurate but the difference remains.
Thanks,
Fei
I have a question regarding numerical accuracy of vasp with broken symmetry ground state of an open-shell, magnetic atom or ion. If initial occupancy of different, physically degenerate orbitals (e.g. with either x^2 or z^2 initially occupied) are specified, the calculated energy should be the same. However, vasp gave me energy differences of a few up to 20 meV. How can I improve the numerical accuracy? I tried ADDGRID=.TRUE. and PREC=Accurate but the difference remains.
Thanks,
Fei