Ionization: Helium to Neon…

Ionization energies (observed) for the 2nd row of the periodic table starting with Helium and ending with Neon follows the following pattern (energy in kJ/mol with 1 Hartree = 2625 kJ/mol):

RealQM gives the following energies (with shell configuration given and list values corresponding to the above graph):

• He 2             (code)  = -2.90       (list -2.903)
• He+ 1           (code)  = -2.00      (list -2.00)
• Li 2+1          (code)  = -7.47      (list -7.48)
• Li+ 2            (code)  = -7.17      (list -7.28)
• Be 2+2          (code) = -14.6       (list -14.5)
• Be+  2+1       (code) = -14.0       (list -14.2)
• B  2+2+1       (code) =  -24.4        (list -24.5)
• B+  2+2         (code) =  -24.2      (list -24.2)
• C 2+4            (code)  = -37.7      (list -37.7)
• C 2+2+2        (code)  = -37.8       (list -37.7)
• C+ 2+2+1     (code)  = -37.3       (list -37.3)
• O 2+4+2       (code)  = -74.9       (list -74.8)
• O+ 2+4+1     (code) = -74.4        (list -74.3)
• N 2+2+3       (code) = -54.4       (list -54.4)
• N+ 2+4         (code)  = -53.7      (list -53.9)
• F 2+4+3        (code) = -99.6       (list -99.4)
• F+ 2+4+2      (code) = -98.8       (list -98.7)
• Ne 2+4+4      (code) = -128.6     (list -128.5)
• Ne+ 2+4+3    (code) = -127.5     (list -127.7)
• Na 2+4+4+1  (code) = -162     (list -162)

Fairly good agreement on 50^3 mesh with list values in the graph capturing the big ionization energies for He and Ne and steady increase from Li with kernel charge/pull, modulo the kinks Be-B and N-O. In RealQM terms the decrease Be-B can be connected to the 1 electron valence of B compared to 2 for Be, and the 2 electron valence of O compared to the 3 electron valence of N. Continue on next row starting with Na on 100^3 mesh…