A..3 Miscellaneous configuration issues

(a)

It is recommended to define the environment variable TMPDIR in the user's .profile file. This should point to a large scratch directory in which MOLPRO jobs will run. Best I/O performance in sorting steps is achieved by using two different scratch directories located on independent disks. If a second scratch directory is available, the environment variable TMPDIR4 should point to this. On fast machines, is advantageous to use striped file systems for minimizing I/O times.

(b)

On Intel Linux systems, the g77 compiler, version 0.5.21 or higher, or else the Portland Group compiler, revision 1.7-6.3 or higher, is required (but note that revision 3.0 should not be used). If the environment variable PGI is set and points to a valid installation, then Portland is used, otherwise g77/egcs. Note that PGI/linux86/bin must be in your PATH before running configure, otherwise the compiler is not found and the installation will fail. The PATH should be defined in the file .profile in the home directory. It is recommended that all environment definitions are made in .profile, and that the file .bashrc contains a single line

. .profile

In this way, .profile will be used by sh, ksh, and bash. The default language level is 90 (-f90), but if a valid 90 compiler is not found, pgf77 or g77 are used as appropriate. Note that Fortran 90 constructs will be used in future versions of Molpro, so it is recommended that the pgf90 compiler is obtained.

There is apparently a bug in the Portland compiler version 3.1-2 when used with a glibc2.1 linux system (e.g. SuSE 6.2 or Redhat 6.1), such that with Molpro's default compiler options, all programs, including those in the very first stage of configure, hang. The fix is to set environment variable OPENMP to 0 before configuration; the unfortunate side-effect is that OpenMP parallelism is disabled. Should you encounter such a hang, set OPENMP=0, then do "make veryclean" in the MOLPRO root directory, and start from scratch with configure. Note that OPENMP=0 might not help unless you do "make veryclean"!

It is strongly recommended on Intel linux systems to use an optimized blas library, particularly if using the g77 compiler. A suitable library can be obtained from
http://www.cs.utk.edu/~ghenry/distrib/.

(c)

On Alpha Linux systems, configure -f77 tries to use the g77 compiler, and configure -f90 tries to use the Compaq fort compiler.

(d)

On SGI systems, the MIPSpro f90 compiler, Version 7.2.1.2m, does not work for the 32-bit (i4) version (wrong results for unknown reason). Therefore, f77 must be used for the time being. Surprisingly, the same f90 compiler works for the 64-bit version (-i8) and is used by default. Should this compiler not be available, or if f77 must be used for any other reason, one has to comment out the following lines in src/opt/bmat.f:

cstart unix-i8 .and. unix-r10000
          backspace inpf3
cend

(e)

On HP-UX 11.0 systems with 64-bit integers (-i8) BLAS=4 cannot be used. This is due to a still unknown system bug.