cumulativeShellClosure

formal source

 103
 104/-- Cumulative electron count at shell closure n.
 105    These are exactly the noble gas atomic numbers. -/
 106def cumulativeShellClosure : ℕ → ℕ
 107  | 0 => 2       -- He
 108  | 1 => 10      -- Ne
 109  | 2 => 18      -- Ar
 110  | 3 => 36      -- Kr
 111  | 4 => 54      -- Xe
 112  | 5 => 86      -- Rn
 113  | n + 6 => 86 + (n + 1) * 32  -- Continuation
 114
 115/-- Period of element Z (which noble-gas-bounded period it belongs to). -/
 116def periodOf (Z : ℕ) : ℕ :=
 117  if Z ≤ 2 then 1
 118  else if Z ≤ 10 then 2
 119  else if Z ≤ 18 then 3
 120  else if Z ≤ 36 then 4
 121  else if Z ≤ 54 then 5
 122  else if Z ≤ 86 then 6
 123  else 7
 124
 125/-- Previous noble gas closure for element Z. -/
 126def prevClosure (Z : ℕ) : ℕ :=
 127  if Z ≤ 2 then 0
 128  else if Z ≤ 10 then 2
 129  else if Z ≤ 18 then 10
 130  else if Z ≤ 36 then 18
 131  else if Z ≤ 54 then 36
 132  else if Z ≤ 86 then 54
 133  else 86
 134
 135/-- Next noble gas closure for element Z. -/
 136def nextClosure (Z : ℕ) : ℕ :=