Table 1. Comparison of success rates (%) for two tangent formula algorithms based on phase relationships.
(a) S-TF with a varying number of strong reflections. (b) Traditional TF (Karle & Hauptman, 1956 ▶), complemented with the most reliable negative quartets (values taken from Sheldrick, 1990 ▶). S-TF is clearly superior, especially for space groups having the origin floating at least in one direction.
| Code | Reference | Space group | N | (a) | (b) |
|---|---|---|---|---|---|
| BHAT | Bhat & Ammon (1990 ▶) | Pc | 200 | 42.5–71.5 | 0.26 |
| HOPS | Jones et al. (1992 ▶) | R3 | 1000 | 9.6–13.7 | 0.56 |
| MBH2 | Poyser et al. (1986 ▶) | P1 | 300 | 39.0–67.6 | 4.7 |
| LOG | Jones et al. (1980 ▶) | P212121 | 108 | 5.3–6.2 | 2.1 |
| SUOA | Oliver & Strickland (1984 ▶) | P212121 | 188 | 0.4–1.8 | 0.06 |
| PEP1 | Antel et al. (1990 ▶) | P212121 | 340 | 0.08–0.2 | 0.01 |