Counting nodal surfaces in molecular orbitals: Elimination of artificial nodes

- We have proposed an algorithm to search for nodes of MOs by using their derivatives.
- We found artificial nodes which would not exist if the space had been expanded using a complete function set.
- We removed artificial nodes by introducing r_fdb and obtained the genuine nodes.
- We characterized the MOs of Li, Be, Zn, H2O and formaldehyde by the numbers of the genuine nodes.