Table 2.
Ratios of multipoles from quantum mechanical calculations, site models, SSDQO, and experiment. All moments have been shifted to a molecular coordinate system centered on the oxygen.
| Model | Θ0∕μ0 (Å) | Θ2∕μ0 (Å) | Ω0∕μ0 (Å2) | Ω2∕μ0 (Å2) | Ω0∕Θ2 (Å) | Ω2∕Θ2 (Å) | Ω2∕Ω0 |
|---|---|---|---|---|---|---|---|
| Exp (gas) | 0.07 | 1.38 | NA | NA | NA | NA | NA |
| MP2 (gas) | 0.06 | 1.36 | –0.72 | 1.03 | –0.53 | 0.75 | –1.42 |
| MP2∕∕B3LYP (gas) | 0.03 | 1.39 | –0.76 | 1.05 | –0.54 | 0.75 | –1.39 |
| BYLYP | 0.07 | 1.34 | NA | NA | NA | NA | NA |
| BYLYP | 0.05 | 1.34 | NA | NA | NA | NA | NA |
| QM∕4MM | 0.05 | 1.18 | –0.70 | 0.84 | –0.59 | 0.71 | –1.35 |
| QM∕4TIP5P | 0.10 | 1.10 | –0.63 | 0.77 | –0.57 | 0.71 | –1.23 |
| QM∕230TIP5P | 0.16 | 1.10 | –0.60 | 0.81 | –0.54 | 0.73 | –1.01 |
| AIMD | 0.07 | 1.11 | NA | NA | NA | NA | NA |
| AIMD | –0.04 | 1.12 | NA | NA | NA | NA | NA |
| SPC∕E | 0.00 | 0.87 | –0.67 | 0.83 | –0.77 | 0.96 | –1.25 |
| TIP3P | 0.10 | 0.73 | –0.52 | 0.72 | –0.70 | 0.98 | –1.39 |
| TIP4P | 0.08 | 0.99 | –0.70 | 0.96 | –0.71 | 0.98 | –1.37 |
| TIP4P-Ew | 0.09 | 0.93 | –0.66 | 0.91 | –0.71 | 0.98 | –1.38 |
| TIP4P∕2005 | 0.08 | 1.00 | –0.71 | 0.97 | –0.71 | 0.98 | –1.37 |
| TIP4P∕Ice | 0.07 | 1.00 | –0.72 | 0.98 | –0.71 | 0.98 | –1.37 |
| TIP5P, TIP5P∕Ew | 0.06 | 0.68 | –0.44 | 0.26 | –0.64 | 0.38 | –0.59 |
| AST | 0.00 | 0.87 | –0.67 | 0.00 | –0.77 | 0.00 | 0.00 |
| SSDQO1 | 0.00 | 1.00 | –0.63 | 0.54 | –0.63 | 0.54 | –0.86 |