  The generalized Hubbard model is an important theoretical model for modeling
strongly correlated materials. To be able to theoretically predict the
properties of the materials, the model requires Hubbard's $U$ and Hund's $J$
parameter that represent the on-site Coulomb and exchange interaction,
respectively. For bare Coulomb interactions, the analytic expression of $U$ and
$J$ are analytically described by Racah's $A,B,C$ parameters. However, the
values of $U$ are too large for transition-metal-based materials. To obtain
more accurate values for realistic materials, we employ a Yukawa-type screened
Coulomb interaction, characterized by screening constant $\lambda$. We
characterize $\lambda$ for transition metals. The modified $A,B,C$ parameters
give a more realistic $U$ and $J$ values.
