N5⁺ Cation (RHF)¶
N₅⁺ is a cyclic pentanitrogen cation with 34 electrons. This example demonstrates asymmetric fragment grouping, PROBCUT to filter low-probability configurations, and AOMNORM to correct the AOM normalization.
Files¶
test/n5+.edfinp — input
test/n5+.wfn — RHF wavefunction
test/n5+.wfn.aom — AOM from PROMOLDEN
test/n5+.edfout — reference output
Input¶
0
n5+.wfn.aom
n5+.wfn
probcut 0.001
aomnorm 1
ngroup 4
1 1
1 3
1 5
2 2 4
end
Fragment setup¶
The molecule is divided into 4 groups with an asymmetric grouping: atoms 1, 3, and 5 each form their own fragment, while atoms 2 and 4 are grouped together into a single two-atom fragment.
Group 1: atom 1 (1 atom)
Group 2: atom 3 (1 atom)
Group 3: atom 5 (1 atom)
Group 4: atoms 2,4 (2 atoms)
This reflects the topology of the ring where atoms 2 and 4 play a symmetric role.
Keywords used¶
PROBCUT 0.001¶
Configurations with probability below 0.001 are not printed. For N₅⁺ this reduces the output from ~1600 lines (at PROBCUT 0.0) to the most chemically relevant configurations.
The sum line in the output shows what fraction of probability is captured:
# 0.9813550159 <-- SUM, 40 PROBABILITIES > 0.001
# 1.0000000001 <--- TOTAL SUM
TOTAL SUM reaching 1.0 confirms AOM normalization is correct.
AOMNORM 1¶
Renormalizes the AOM by adjusting atom 1's elements so the sum rule is exactly satisfied. The corrected AOM is written to n5+.wfn.aom.normalized.
Key output¶
Average populations¶
<n( 1)_alpha> = 3.422784 <- N atom 1
<n( 2)_alpha> = 3.656765 <- N atom 3
<n( 3)_alpha> = 3.131843 <- N atom 5
<n( 4)_alpha> = 6.788608 <- N atoms 2+4 (two-atom group)
Group 4 (two N atoms) carries ~13.6 electrons total, consistent with 2 × 6.8 ≈ 13.6 electrons per N atom in the ring. The asymmetry between single-atom groups reflects the N₅⁺ electronic structure.
Running¶
cd test/
OMP_NUM_THREADS=4 ../edf-omp < "n5+.edfinp" > n5plus_new.edfout
Note
Shell quoting may be needed for the n5+ filename depending on the shell.