Q. Which kind of computational resources is necessary to perform SAC-CI calculations?

 

A. The current version of SAC-CI on G03 tries to store the MOERI (Election Repulsion Integral in Molecular Orbital base) in core memory.  Therefore, it is preferable to have the core-memory as large as possible.  In addition, the cache size is also important for quick calculations.  When you perform very fine calculation with large number of excitation operators, the size of the read-write file could be very large. In this case, the disk I/O becomes bottleneck of the computation.