1-Phase Seminvariants and Harker Section. II-A New Procedure

The algebraic relations between 1-phase seminvariants of first rank and Harker sections recently described by Ardito, Cascarano, Giacovazzo and Lui? [Z. Kristallogr. 172 (1985) 25 - 34)] are further on discussed. A special least-squares procedure is proposed for discriminating spurious peaks among those lying on Harker sections and for improving positional and thermal parameters of heavy atoms. The first applications show that 1-phase seminvariants of first rank may be reliably estimated also for crystal structures with medium weight atoms.