Ab initio molecular dynamics calculations call for substantial computer resources. Memory and CPU time requirements make it necessary to run projects on the largest computers available. Today and in the foreseeable future, these high-end resources are provided exclusively by parallel computers. There are many different types of parallel architectures available, differing in their memory access system and their communication system. In addition, widely different performances are seen for the amount of data that can be sent from one processor to another per unit time (bandwidth) and the minimal time needed to send a small message (latency). Furthermore, different parallel programming paradigms are supported. ...