Ab initio self-consistent field calculations are performed on N02-(H20), and NO;(H20), (n = 1-3) clusters. Optimized geometries, t o t a l energies, binding energies, and net atomic charges are presented for various structures of the clusters.NMR has been employed to measure the orientational order parameters for the nematogenic homologous series trans-4-alkyl(4-cyanophenyl)cyclohexanes by studying the dipole-dipole splittings. The values of the order parameters are compared with those obtained by optical studies.

Die Zukunft der Subnitrid‐Chemie erscheint vielversprechend :M6‐Oktaeder mit zentralem N‐Atom wurden jetzt in der neuen Verbindung Na16Ba6N und im schon länger bekannten „Ag8Ca3”︁ nachgewiesen ‐ in Wirklichkeit handelt es sich dabei um das isotype Ag16Ca6N (mit 0.7% N)! Die M6N‐Oktaeder sind in eine Matrix aus Na bzw. Ag eingebettet. Zahlreiche Phasen mit Ag8Ca8‐Struktur vom Typ Ni6Si2M3 und Ni6Al2M3 (M = Seltenerdmetall) könnten sich ebenfalls als durch interstitielle Atome stabilisiert erweisen.

Ab initio calculations are performed with 6–31G basis set to study the geometry and binding of the H3O 2−, H5O 3−, H7O 4−, and H9O 5− complexes. The H3O 2− complex is also investigated with the 6–31 G* basis set and MP2 (Moller–Plesset perturbation theory of second order).

The antiviral drug 1-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl) thymine (FMAU) exhibits a high therapeutic index against a number of herpesviruses. As with other drugs which are nucleoside analogs, such as 1-(2-fluoro-2-deoxy-beta-D-arabinofuranosyl)-5-iodocytosine and others, the activity seems to be strongly related to the presence of a fluorine atom in the sugar moiety, in the arabino position. Theoretical calculations, using quantum-chemical methods, are used to elucidate the role of the fluorine in the arabino position and to provide information about the sugar puckering. The results seem to indicate that the fluorine atom prevents the rotation of the base around the sugar-base bond, locking it into an anti structure (Fig. 2,A3) which might be related to its exposure to enzymatic attack. The sugar study confirms the endo position (above the plane) of the C'2 carbon as opposed to the endo position of the C'3 carbon.

A Gaussian basis set consisting of 12 s-type, 8 p-type, and 7 d-type functions have been optimized for the second row transition metals (Y–Cd). Orbital energies along with the coefficients and exponents are presented for the neutral, monopositive, and dipositive atoms. Three additional s-type functions were used to represent occupied 5s orbitals, when necessary.