New algorithms and methods

Considering quantum chemistry in particular, hardware improvements have made it possible to tackle different classes of problems, posing a new set of challenges for parallel program developers. For instance, parallelization of 

The parallel efficiency (also defined in section 5.2.1), which measures how well the computer is utilized, is then given as 

In this case, there is a fixed upper limit to the achievable speedup, and the efficiency decreases as the number of processors increases, regardless of the problem size. Thus, much work must be invested to achieve efficient parallelization of linear-scaling methods these methods involve a large number of steps that scale linearly in N, and each step must be parallelized to achieve high efficiency when running on large numbers of processors. 

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Another factor is that technological advances enabled deepwater ventures on the U.S. OCS, as they had elsewhere in the North Sea off the U.K. and Norwegian coasts, the vast southwest Pacific, the south Atlantic off African and Brazilian coasts, and the Persian Gulf New algorithms and methods of seismic imaging were being applied to locate oil and gas buried deeply in the seabed and to evaluate the suitability of... 

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