Table S1. Geometric Parameters of Trans-Oxalyl Chloridefluoride in the Ground Electronic

Table S1. Geometric parameters of trans-oxalyl chloridefluoride in the ground electronic state. Bond lengths in Angstrom, angles in degrees.

Parametera / B3LYP/
6-311+G(3d) [11] / MP2/
6-311+G(3d) [11] / QCISD/
6-311+G(d)b [11] / MP2/
cc-pVTZ / MP2/
cc-pVQZ / CASPT2(8-6)/
cc-pVTZ / QCISD(T)/
cc-pVTZ / CCSD(T)/
cc-pVTZ
r(C–C) / 1.546 / 1.540 / 1.547 / 1.537 / 1.536 / 1.535 / 1.541 / 1.540
r(C=O)F / 1.176 / 1.185 / 1.181 / 1.186 / 1.182 / 1.184 / 1.184 / 1.184
r(C=O)Cl / 1.180 / 1.193 / 1.188 / 1.192 / 1.189 / 1.190 / 1.190 / 1.190
r(C–F) / 1.335 / 1.337 / 1.330 / 1.329 / 1.328 / 1.326 / 1.329 / 1.328
r(C–Cl) / 1.758 / 1.741 / 1.745 / 1.743 / 1.737 / 1.738 / 1.753 / 1.751
OCCF / 127.1 / 126.9 / 126.8 / 126.9 / 126.9 / 126.6 / 126.7 / 126.7
OCCCl / 123.6 / 123.6 / 123.0 / 123.7 / 123.7 / 123.4 / 123.4 / 123.4
FCO / 123.4 / 123.6 / 123.0 / 123.8 / 123.7 / 123.7 / 123.7 / 123.7
ClCO / 124.1 / 124.3 / 124.1 / 124.4 / 124.4 / 124.3 / 124.3 / 124.3
FCC / 109.5 / 109.5 / 109.7 / 109.4 / 109.4 / 109.7 / 109.6 / 109.6
ClCC / 112.3 / 112.1 / 112.9 / 111.9 / 111.9 / 112.3 / 112.3 / 112.3
dFCOC / – / – / – / 180.0 / 180.0 / 180.0 / 180.0 / 180.0
dClCOC / – / – / – / 180.0 / 180.0 / 180.0 / 180.0 / 180.0
dOCCO / 180.0 / 180.0 / 180.0 / 180.0 / 180.0 / 180.0 / 180.0 / 180.0

a indexes F and Cl mean that the bond or angle are related to FCO and ClCO fragments, respectively;

bthesumofvalenceanglesforFCOfragmentislessthan 360º that is obviously connected with an error in [11].