A neutron diffraction study of liquid formamide

Abstract

Neutron diffraction data on seven different isotopes of formamide, containing ¹H and ²H, are reported. Background, self-absorption of the sample and container and multiple scattering corrections were done in the previous way, whereas a new empirical procedure for the inelasticity correction is presented. After separation of the coherent scattering contribution into intramolecular and intermolecular parts the latter was analysed in terms of four expansion coefficients of the molecular pair-correlation function. These give information about the molecular centre-centre distributions and orientational correlations. It is found that in the first neighbour sphere at 4.2 Å an antiparallel orientation of the molecules is preferred, whereas a parallel orientation prevails at 5.1 Å.