Table 3. Relative deviations (in %) of VPT2 (aVQZ) rotational constants of cis-formic acid from the experimental values of Winnewisser and co-workers39.

	B2PLYP-D3(BJ)	B3LYP-D3(BJ)	MP2	M06-2X	ωB97-XD	PBE0-D3(BJ)	PM3
ΔA0/A0	+0.1	+0.4	–0.3	+1.4	+1.2	+1.1	–18.9
ΔB0/B0	–0.5	–0.3	–0.5	+0.6	+0.6	+0.6	+9.8
ΔC0/C0	–0.4	–0.3	–0.5	+0.7	+0.6	+0.6	+5.3
	–0.3	–0.1	–0.4	+0.9	+0.8	+0.8	–1.3