Table 1.

Calculated Active Site Electric Fields and Their Geometry Relative to the Ligand’s C=O Bond Vector^a

coordinatesa	DHN (Substrate like)		19NT (TS like)		TS
	X-ray (1)	gas phase opt. (2)	X-ray (6)	gas phase opt. (7)	gas phase opt. (5)
Field magnitudeb $|{\overrightarrow{F}}_{\text{enz}}|$ (MV/cm)	−139.5	−105.3	−160.4	−100.9	−151.8
Feld projectionc ${\overrightarrow{F}}_{\text{enz }}\cdot {\widehat{u}}_{CO}$ (MV/cm)	−127.6	−83.5	−141.7	−76.1	−144.6
%alignedd	91%	79%	88%	75%	95%
Δstabilizatione (kcal mol−1)	6.6	reference	10.7	reference	/
C=O…O16 (Å)	2.53	/	2.57	/	2.70
C=O…O103 (Å)	2.76	/	2.65	/	2.48

^aSee Table S2 and Figure S3 for complete simulation scheme and results. The number of each entry corresponds to the respective species in Figure 3 and Figure S3.

^bThe electric field magnitude, $|{\overrightarrow{F}}_{\text{enz}}|$, is the average of the magnitude of the enzyme’s electric field at the C and O atoms of the bound ligand.

^cThe electric field projected on the carbonyl is calculated by ${\overrightarrow{F}}_{\text{enz}}\cdot {\widehat{u}}_{CO}$, and also equals $|{\overrightarrow{F}}_{\text{enz}}|$ · %aligned, where $|{\overrightarrow{F}}_{\text{enz}}|$ is the magnitude of the enzyme’s field.

^dThe %aligned is calculated by eq 3.

^eΔstabilization (the stabilization energy gained from C=O distortion) is the difference of the field projection multiplied by the dipole of the carbonyl (1 MV cm⁻¹ D ≃ 0.048 kcal mol⁻¹).