ISSN:
0192-8651
Keywords:
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Computer Science
Notes:
Ab initio molecular geometries and vibrational frequencies of various isolated vanadate species (VO3-4, HVO2-4, H2VO-4, and V2O4-7) were calculated using different pseudopotentials. The relative merits of these were assessed by comparing the calculated molecular parameters with the corresponding values obtained from calculations at all-electron levels and, whenever available, from X-ray studies for the salts. The calculations were extended to higher oligomers (V3O5-10, V4O6-13, and V4O4-12) using the pseudopotential whose basis functions are (10s5p5d)/[2s1p1d] (55/5/5) on vanadium and (4s4p)/[2s2p] (31/31) on oxygen, which yielded the best compromise between accuracy and computational effort. The results indicate a linear centrosymmetric geometry for the isolated V2O4-7 anion. The higher oligomers have less than 180° V(SINGLE BOND)O(SINGLE BOND)V angles, except the noncyclic tetraoligomer which has a linear central V(SINGLE BOND)O(SINGLE BOND)V angle (180°). The cyclic V4O4-12 species presents a planar structure with all the vanadium and bridging oxygen atoms in the same plane. This structure was alrea dy reported for the [(CH3)CNH3][V4O12] salt. The results suggest a lower stability of the linear V4O6-13 species, in agreement with previous reports. © 1996 by John Wiley & Sons, Inc.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcc.1
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