PNNL-13501 - Pacific Northwest National Laboratory

Developing and testing the prototype code was done on
an IBM Risc/6000 processor (67 MHz). In the largest test
to date, HostBuilder generated and evaluated 104,172
possible architectures for connecting two chelate rings to
form a tetradentate host for a metal ion guest. The time
spent building and ranking these structures was 55 CPU
seconds, (a rate of 1,894 molecules per second). Given
recent advancements in processor speed, use of newer
hardware should increase this rate to better than 20,000
molecules per second, allowing us to evaluate more than a
million molecules per minute. We have demonstrated
that HostBuilder executes with sufficient speed to allow
the development of multi-generation building algorithms.
In a multi-generation building mode, the user will specify
the number of host fragments that would form the final
structure and the code would build the host by
sequentially connecting these fragments. For example,
the best hits from the initial generation (linking two
unidentate fragments to form a bidentate host) would be
used as input for the next generation (adding a unidentate
fragment to a bidentate host to form a tridentate host).
Summary and Conclusions
Prototypes of the HostBuilder program and link library
have been completed. Tests demonstrate that the building
and evaluation algorithms are computationally very
efficient and with recent hardware, we estimate that
speeds in excess of one million molecules per second are
attainable. Completion of this project in FY 2001 will
entail
• switching from disk-based data storage to RAMbased
data storage
• developing improved methods for building
macrocyclic structures
• developing logic and control algorithms for the multigeneration
building mode
• increasing the number of structures in the link library.
Computational Science and Engineering 131