Day 493: Variational Method for Helium

Learning Objectives

• •**Apply** the variational principle to helium with a scaled wave function
• •**Calculate** the energy functional $E(Z_{\text{eff}})$
• •**Optimize** to find $Z_{\text{eff}} = 27/16 = 1.6875$
• •**Interpret** $Z_{\text{eff}}$ in terms of screening
• •**Compare** variational results with perturbation theory
• •**Explore** improved trial functions for greater accuracy

Today's Schedule (7 hours)