The Derivation of the rs Structure by the Use of a Nondiagonal Weight Matrix for Rotational Constants

The use of a nondiagonal weight matrix in a least-squares analysis of the quantities which themselves are derived from another least-squares analysis is discussed in relation to the analysis of rotational constants in determining molecular geometry. The method is applied to the calculation of the rs structure of ethylene oxide, and the result is compared with those obtained by Kraitchman’s formula and by a least-squares fit by the use of a diagonal weight matrix.