The second representation of a triplet invariant [Giacovazzo (1977). Acta Cryst. A33, 933-944] is a collection of special quintets. In the present paper, the triplet is embedded in many more additional quintets obtained in a special way by symmetry operations on the indices of the structure factors. The method of joint probability distribution functions has been used to derive a formula for estimating triplets via the information contained in the basis and in the cross terms of the quintet invariants. The P10 formula [Cascarano, Giacovazzo, Camalli, Spagna, Burla, Nunzi & Polidori (1984). Acta Cryst. A40, 278-283] is a special case of the new formula, here called P13. The new expression has been applied to practical cases.
The Probabilistic Estimation of Triplet Invariants: the Formula P13
BURLA, Maria Cristina;
1994
Abstract
The second representation of a triplet invariant [Giacovazzo (1977). Acta Cryst. A33, 933-944] is a collection of special quintets. In the present paper, the triplet is embedded in many more additional quintets obtained in a special way by symmetry operations on the indices of the structure factors. The method of joint probability distribution functions has been used to derive a formula for estimating triplets via the information contained in the basis and in the cross terms of the quintet invariants. The P10 formula [Cascarano, Giacovazzo, Camalli, Spagna, Burla, Nunzi & Polidori (1984). Acta Cryst. A40, 278-283] is a special case of the new formula, here called P13. The new expression has been applied to practical cases.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
