ISSN:
0192-8651
Schlagwort(e):
Computational Chemistry and Molecular Modeling
;
Biochemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Informatik
Notizen:
Normal coordinate calculations have been performed for urea and deuterated urea in the crystalline state. We have used the modified Urey-Bradley-Shimanouchi intramolecular potential energy function and a rather sophisticated intermolecular energy function to reproduce I.R. and Raman frequencies with an average error of 2 cm-1. The general agreement between the calculation and experiment suggests that intermolecular interactions must be taken into account to determine reliable intramolecular parameters of the potential energy function, mainly the barrier to internal rotation around the C—N bond. The intermolecular energy function, which consists of the Buckingham function and an explicit harmonic function for hydrogen-bonding, then has the merit to reproduce quite well the observed frequencies of lattice vibrations.
Zusätzliches Material:
11 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jcc.540110504
