Optimization calculations, partial geometry

It is feasible to carry out Hartree-Fock calculations on our available computer resources (an SGI Crimson Elan Workstation) using an STO-3G basis set with full geometry optimization of CeoMu but only partial geometry optimisations of the ChoMu isomers. Fig. 1 shows planar graphs of Ceo and C70 with the carbon atoms suitably labelled for future reference. 

Pendergast and Fink154 have performed somewhat similar calculations, including Cl, on the surface for reaction (9). Partial geometry optimizations were carried out... 

Of particular interest are the zeolites with aluminum atoms partially substituted in their framework by boron. Calculations with optimization of the geometry of clusters have shown that the energy gains in the trigonal-to-tetrahedral state transformations in the H forms of such zeolites were 1.9 and 14.1 kcal/mol for boron and aluminum, respectively. It may therefore be concluded that H forms of boralites, if they exist, should be considerably less stable than those of zeolites. 

Fig. 5 Fully optimized geometries and calculated partial charges of and Sjo ...

The calculations were then repeated for the two aldehydes complexed by a proton or by a lithium cation, using structure parameters obtained by partial geometry optimization of the corresponding complexes of formaldehyde. No significant change in the relative stabilities of the diastereomeric transition states was found. 

All results of calculations shown in the present article except the HMO calculations, are the outcome of complete or partial optimization of geometry. 

---