Slater's Rules (Screening Constants) (sigma = sum of screening contributions per Slater groups)

jee-mainjee-advancedneet-ug

sigma = sum of screening contributions per Slater groups

What each symbol means

SymbolWhat it stands for
\sigmaTotal screening constant for the chosen electron
group factorsSame (ns,np): 0.35 each (1s is 0.30); (n−1) shell: 0.85 each e⁻; (n−2) and lower: 1.00 each; (n−1)d,f: 1.00 for ns/np tests

When to use this

Approximate rules for estimating σ then Z_eff. d- and f-block cases have exam-specific variants; always follow the problem’s stated grouping if it differs slightly from your coaching table.