TABLE III.
Intermolecular energies for water dimer (in kcal/mol) in several geometries as defined in van Duijneveldt-van de Rijdt et al. (Ref.49). All results calculated with B3LYP/aug-cc-pVTZ (values in parentheses correspond to B3LYP/6-31G*). For the density fitting result the fitted densities were obtained from the exact DFT calculation (CSOV). MP=midpoints.
| Level of theory | Water dimer geometry | ||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| SAPT (CCSD)a | −8.023 | −6.725 | −6.494 | −6.699 | −5.688 |
| SAPT (MP3)a | −8.081 | −6.814 | −6.601 | −6.733 | −5.776 |
| CSOV (DFT) | −8.109(−8.224) | −6.854(−7.022) | −6.643(−6.908) | −6.727(−6.150) | −5.768(−5.507) |
| Multipoles, MP | −6.15 | −5.08 | −4.91 | −4.86 | −4.17 |
| EMTP*, MPb | −8.03 | −6.85 | −6.67 | −7.26 | −6.67 |
| A1 | −7.361(−8.076) | −6.148(−6.758) | −5.961(−6.575) | −6.297(−6.506) | −5.552(−5.721) |
| A1, (O)c | −7.319(−7.067) | −6.206(−5.984) | −6.031(−5.879) | −6.343(−6.088) | −5.485(−5.466) |
| A1, MP (H)d | −8.259(−9.889) | −7.065(−8.447) | −6.895(−8.285) | −6.414(−6.159) | −5.656(−5.377) |
| A1, MP (O)e | −8.063(−7.817) | −6.871(−6.657) | −6.668(−6.568) | −6.031(−5.669) | −5.123(−5.034) |
| P1 | −8.890(−8.415) | −7.477(−7.144) | −7.294(−7.059) | −6.774(−6.269) | −5.992(−5.759) |
| P1, (O)c | −8.216(−8.283) | −6.932(−7.090) | −6.710(−6.979) | −7.137(−6.437) | −6.082(−5.745) |
| P1, MP (H)d | −8.235(−8.243) | −6.914(−7.028) | −6.686(−6.910) | −6.488(−6.160) | −5.563(−5.524) |
| P1, MP (O)e | −8.149(−8.241) | −6.897(−7.059) | −6.689(−6.956) | −6.726(−6.242) | −5.642(−5.582) |
| g03 | −8.112(−8.210) | −6.886(−7.009) | −6.696(−6.897) | −6.663(−6.259) | −5.900(−5.612) |
| g03, (O)c | −8.613(−8.339) | −7.405(−7.121) | −7.254(−7.011) | −6.463(−6.063) | −5.801(−5.455) |
| g03, MP (H)d | −8.117(−8.222) | −6.863(−7.041) | −6.663(−6.933) | −6.733(−6.187) | −5.803(−5.539) |
| g03, MP (O)e | −8.048(−8.231) | −6.838(−7.022) | −6.647(−6.909) | −6.566(−6.169) | −5.760(−5.514) |