Fig. 7: Geometries of polyyne compounds.
From: Artificial intelligence-enhanced quantum chemical method with broad applicability
a Correct polyynic (red) geometry of C18 predicted by AIQM1 (bond lengths in red) and UCCSD/def-TZVP (bond lengths in black from ref. 56) and its incorrect alternative cumulenic (blue) geometry predicted by B3LYP/6-31G* (bond lengths in blue). b X-ray structure of 1b compound from ref. 57 assigning too short triple C≡C bond lengths (shown in black). c AIQM1 geometry of 1b with revised bond lengths (shown in red). Bond lengths are in Å. Other bond lengths and the coordinates of AIQM1 geometry are given in the Supplementary Data 1 sheet S23.
