aspects of the included physics are the most important for driving fragmentation. Simulations that start from simpler initial conditions and that focus on exploring the importance of a single free parameter therefore play an important role, which is complementary to that of fully cosmological simulations. A good example is the recent work by Machida and collaborators [@mach08; @mach09] which examined the influence of the initial rotational energy of the gas, and found that zero metallicity clouds with sufficient initial rotational energy could fragment into tight binaries. Another example, and one which explores a much lower density regime, is the study by @jap09a [@jap09b], who showed that the fragmentation behavior depends sensitively on the adopted density profile of the primordial halo.

In this paper, we perform a similar study into the effects of the initial turbulent energy of the gas. Our motivation comes from the fact that recent high-resolution cosmological simulations have shown that the self-gravitating regions in which Pop. III star formation occurs contain significant turbulent motions [see e.g. @2008MNRAS.387.1021G]. From studies of present-day star formation, we know that such turbulent motions can lead to the fragmentation of initially marginally unstable gas clouds , and so it is instructive to 