Special notes for parallel computers

Some parts of MOLPRO are able to exploit parallelism on computers such as the Cray T3E and IBM SP; in principle, workstation clusters and shared memory machines are also supported, although no tuning has been done, and performance is likely to be very poor. Use of this feature requires the mpp module (not currently generally distributed). Some additional considerations are needed at configuration time:

(a)

The parallel implementation relies on the Global Arrays toolkit, version 2.4 or later. This is freely available (from http://www.emsl.pnl.gov:2080/docs/global/ga.html), and should be installed prior to compiling MOLPRO. Note that it is necessary to set the maximum number of global arrays to at least 256 (MAX_ARRAYS in g/global/src/config.h) before building GA. The -L option for configure should specify the directory to search for the GA and associated libraries.

(b)

The option -mpp should be given to configure to force correct building; configure may also prompt for this information where necessary.

(c)

On the Cray T3E, the system header file shmem.fh should be copied from its standard system location (e.g., /opt/ctl/craylibs/craylibs/include/mpp/shmem.fh) to the directory src/common.