The generalized Sturmian method is a direct configuration interaction method
for solving the Schr\"odinger equation of a many-electron system. 
The configurations in the basis set
are solutions to an approximate Schr\"odinger equation
with a weighted potential $\beta_\nu V_0({\bf x})$, the weighting factors $\beta_\nu$
being chosen in such a way as to make the set of solutions isoenergetic. 
The method is illustrated by calculation of atomic excited states and used to generate
natural orbitals