. 2021 Oct 1;125(40):9011–9025. doi: 10.1021/acs.jpca.1c06574

Table 4. Comparison of IQA Two-Center Terms for Covalent Bonds in Molecular and Solid Phases β-N₂ and CO₂^a.

system	A–B	R^AB	δ^AB	E_nn^AB	E_ne^AB	E_ne^BA	E_Coul^AB	E_cl^AB	E_x^AB
N₂ (mol.)	N–N	1.108	3.041	23.399	–21.944	–21.944	20.716	0.227	–0.906
N₂ (solid)	N–N⁽¹⁾	1.108	3.000	23.399	–21.952	–21.953	20.726	0.220	–0.903
CO₂ (mol.)	C–O	1.149	1.396	22.114	–25.443	–13.413	15.453	–1.289	–0.444
CO₂ (solid)	C–O⁽¹⁾	1.149	1.323	22.114	–25.646	–13.152	15.269	–1.415	–0.426
CO₂ (mol.)	O–O	2.297	0.433	14.743	–16.981	–16.981	19.563	0.343	–0.054
CO₂ (solid)	O–O⁽²⁾	2.297	0.407	14.743	–17.081	–17.081	19.793	0.373	–0.052

Nearest-neighbor interactions are denoted with A–B⁽¹⁾, second neighbors with A–B⁽²⁾, and so on. Energies in Ha; distances in Å.

Table 4. Comparison of IQA Two-Center Terms for Covalent Bonds in Molecular and Solid Phases β-N2 and CO2a.