In the reaction of hydration of carbon dioxide, a carbon dioxide molecule reacts favorably with the water-dimer (2) than the water-monomer (1). The results of semi-empirical calculation using MOPAC agree with the results of the ab initio calculation reported previously (Fig. 6). The present reaction system is visualized by the computer-graphics animation based on the results of the MOPAC calculation.
The software for band-shape analysis (SP-DOS) programmed by the C-language under MS-DOS has been developed into Windows98/95/ and WindowsNT (SP-WIN) using Pascal language (Delphi) with GUI. The SP-WIN can deal with a number of data under the no limiting condition of 1 MB memories on MS-DOS. Even a beginner can easily analyze many types of spectra (IR, UV, VIS and so on) by using a mouse device and a user friendly interface, which are typical features of a Windows operating system. The multi windows system can show many results of analysis at the same time on a high resolution display.
In order to have an initial molecular geometry simply and fast, we modified the extended Huckel method and developed a geometry optimize method using only total energy. The difference between calculated and observed values of small hydrocabon molecules is less than about 10%.Parallel processing of the extended Huckel is very efficient up to 8 PC-cluster system because the efficiency for the extended Huckel calculation of DNA(115 atoms and 286 dimension) is bigger than 90%.
We have performed parallel processing on the ab initio crystal orbital calculations of one-dimensional polymers using the TCGMSG and MPI/LAM message passenger. An IBM RS6000 cluster (4 CPU), and personal computer cluster with Intel Pentium II 450MHz (2CPU) and Celeron 433MHz (2CPU) were used for the computational environment. We found that the Celeron CPU was less effective than Pentium II in the parallel calculations. Our previous work showed that the distribution of the CPU demand did not work well when 16 nodes were used to calculate the two-electron integrals in parallel. We found that the new algorithm incorporated in the present article improved the distribution. The CPU time increased when using the MPI interface, because there is an overhead to transfer the array in MPI_ALLREDUCE function. We also determined that the real through-put time was strongly dependent on the structure of the network system.