CFOUR

I have been testing the CFOUR (http://www.cfour.de) program for the past couple of weeks, and it seems to have potential. But at the same time it should be said that it is annoyingly critical with the input. Every space counts, i.e. it matters if you place an atom name as " H" (i.e. with a space before it) or "H" .. The same happens in the definition of the Z-matrix.
This makes the program not very user-friendly.

Also the installation is somehow not very user-friendly, e.g. it took me a while to get the program to work in the standard way of

PROGRAM < input > output

where I expect only the output to get back on my home disk. After some experimentation I found out that CFOUR works differently, and had to be modified with a runxcfour script.

BUT:
apart from those hiccups (that undoubtedly will be smoothed one day), the program is very very fast. E.g. I never imagined that I could do a NMR calculation with CCSD(T) on a water hexamer.
But we just did and that on just one node... (amazing discoveries Mike!).