When running lstart you will first be asked interactively to specify an XC-potential switch. Currently 5 (LSDA, Perdew and Wang 92) as well as 13 and 14 (two GGAs, Perdew et al. 92 and Perdew et al. 96, respectively) are officially supported.
In addition the program asks for an energy, separating core from valence states. Usually -6.0 Ry is a good choice, but you should check for each atom how much core charge leaks out of the sphere (bottom of case.outputs). If this is the case one should lower this energy and thus include these low lying states into the valence region.
The rest of the input is described in the sample input below.
Note: Only the data at the beginning of the line are read and then a comment describes the respective parameters. This file can be generated automatically in WIEN in a BOX using ``RunPrograms Struct Generator''. To edit this file by hand choose ``View/Edit Input Files'' and choose case.inst.
------------------ top of file: case.inst ------------------- ZINC Ne 6 (inert gas, # OF VALENCE ORBITALS not counting spin) 3,-1,1.0 N ( N,KAPPA,OCCUP; = 3S UP, 1 ELECTRON) 3,-1,1.0 N 3S DN 3,-2,2.0 N 3P UP 3,-2,2.0 N 3P DN 3, 1,1.0 N 3P*UP 3, 1,1.0 N 3P*DN 3,-3,3.0 P 3D UP 3,-3,3.0 P 3D DN 3, 2,2.0 P 3D*UP 3, 2,2.0 P 3D*DN 4,-1,1.0 P 4S UP 4,-1,1.0 P 4S DN **** END OF Input **** END OF Input ------------------- bottom of file ---------------------------
Interpretive comments follow:
The quantum numbers are defined as follows (see e.g. Liberman et al 65):
Spin quantum number: s = +1 or s = -1
Orbital quantum number j = l + s/2
Relativistic quantum number
= -s(j + 1/2)
begin:symmetry