A..3.2 Prerequisites

The following are required or strongly recommended for installation from source code.

1. A Fortran 90 compiler. Fortran77-only compilers will not suffice. On most systems, the latest vendor-supplied compiler should be used.

   For IA32 Linux (for example Intel Pentium or AMD athlon) the recommended compilers are the Intel Compiler ifort version 9.0 or higher or the Portland pgf90 compiler version 6.0 or higher. For Opteron and EM64T systems the recommended compilers are Portland version 6.0 or higher, Pathscale compiler pathf90 version 2.3 or higher, or the Intel Compiler version 9.0 or higher. The full list of supported compilers can be found at http://www.molpro.net/supported.

2. GNU make, freely available from http://www.fsf.org and mirrors. GNU make must be used; most system-standard makes do not work. In order to avoid the use of a wrong make, and to suppress extensive output of GNU make, it may be useful to set an alias, e.g., alias make='gmake -s'.

3. The GNU wget utility for batch-mode http transfers, although not needed for installation, is essential for any subsequent application of patches that implement bug fixes.

4. About 10GB disk space (strongly system-dependent; more with large-blocksize file systems, and where binary files are large) during compilation. Typically 50Mb is needed for the finally installed program. Large calculations will require larger amounts of disk space.

5. One or more large scratch file systems, each containing a directory that users may write on. There are parts of the program in which demanding I/O is performed simultaneously on two different files, and it is therefore helpful to provide at least two filesystems on different physical disks if other solutions, such as striping, are not available. The directory names should be stored in the environment variables $TMPDIR, $TMPDIR2, $TMPDIR3,$\dots$. These variables should be set before the program is installed (preferably in .profile or .cshrc), since at some stages the installation procedures will check for them (cf. section A.3.6).

6. If the program is to be built for parallel execution then the Global Arrays toolkit is needed. We recommend version 4.0.1 (although earlier versions should also work). This is available from http://www.emsl.pnl.gov/docs/global and should be installed prior to compiling MOLPRO. In some installations, GA uses the tcgmsg parallel harness; on others, it sits on an existing MPI subsystem, and on others, it makes use of the native parallel subsystem (e.g., LAPI). MOLPRO can be built to use any of these, although it is not normally recommended to use MPI where other possibilities exist. For more information, see section

   A.3.3.

7. The source distribution of MOLPRO, which consists of a base compressed tar archive with a file name of the form molpro.2006.1 .tar.gz, together, possibly, with one or more module archives with file names of the form molpro.module.2006.1 .tar.gz. The modules contain code which is not generally distributed, or features which are not always required to install the code. An example is the program developers' kit (module=develop). The archives can be unpacked using gunzip and tar. All archives must be unpacked in the same directory. It is essential that the base archive is unpacked first, and advisable that any modules are unpacked before further installation.

   Under some circumstances, MOLPRO is delivered as a single tar file with a name of the form molpro.all.2006.1 .tar. This archive contains all necessary base and module compressed tar archives, together with a shell script unpack which performs the unpacking described above.