Prerequisites

As far as possible the examples were designed to be doable on a single processor desktop PC with a fair amount of memory, For some examples somewhat longer execution times have to be expected or jobs should be run on a cluster for faster turnaround times. For details on compiling and installing CPMD, please see section 2. Please note that the tutorial examples were deliberately chosen to be small to they execute fast, most serious applications of CPMD will need a lot of CPU power, i.e. a big parallel machine or cluster and CPMD can actually scale to a very large number of nodes[5,6]. To take full advantage of your (large) machine you thus need to compile a custom parallel executable from the source code and specifically use optimized libraries and settings for your local machine. CPMD is well parallelized using a distributed memory MPI-based parallelization plus an optional and independent OpenMP parallelization for SMP nodes (see section 2.4).

The following examples assume, that you create a separate subdirectory for each group of calculations containing the input file(s) and the pseudopotential file(s), and that you have a usable serial CPMD executable in your search path under the name cpmd.x. You can then run the calculations in that directory by typing something like this:

            cpmd.x example.inp > example.out

Additionally some examples contain small scripts to help you extract data from the calculations. These assume that you are working in a Unix-like environment and they were (usually only) tested on a Linux machine.