Cutoff radii of pseudopotentials are specified by the following keyword:
<pseudo.NandL 0 2 0 1.50 0.0 1 2 1 1.62 0.0 pseudo.NandL>The first number specifies a serial number beginning from zero, which is used in the specification of the keyword, local.part.vps. In the second or third columns, a principal number and an angular momentum quantum number are given. The fourth column provides a cutoff radius (a.u.) for the generation of pseudopotentials. Although an optimum cutoff radius is determined so that the generated pseudopotentials has a smooth shape without distinct kinks and a lot of nodes, however, the selection includes somewhat an empirical factor. The fifth column provides an energy at which each pseudopotential is genenerated. However, if the state is occupied (non-zero occupation), then the eigenenergy is used instead of the value given by the fifth column. The energy given by the fifth column is used for only a state with zero occupation. Regardless of the occupation number, the fifth column has to be provided. It is also possible to take into account semicore states in the generation of pseudopotentials. For example, if you want to include 3s and 3p states as semicore states in a sodium atom, the specification is as follows:
<pseudo.NandL
0 3 0 1.8 0.0
1 3 1 2.3 0.0
2 4 0 1.8 0.0
3 4 1 2.3 0.0
pseudo.NandL>
In this case, a pseudopotential is generated for the lowest state
in each angular momentum quantum number in the BHS [5] and
TM [4] schemes. On the other hand, the MBK scheme [6] takes
multiple states with the same angular momentum into account in the
construction of pseudopotential. The treatment significantly increases
the transferability of pseudopotential. So, in most cases the MBK scheme
is the best choice in ADPACK Ver. 2.2.