  We investigate the ab-initio formation of super-massive stars in a pristine
atomic cooling halo. The halo is extracted from a larger self-consistent parent
simulation. The halo remains metal-free and star formation is suppressed due to
a combination of dynamical heating from mergers and a mild ($J_{\rm LW} \sim 2
- 10 \ J_{21}$(z)) Lyman-Werner (LW) background. We find that more than 20 very
massive stars form with stellar masses greater than 1000 M$_{\odot}$. The most
massive star has a stellar mass of over 6000 M$_{\odot}$. However, accretion
onto all stars declines significantly after the first $\sim$ 100 kyr of
evolution as the surrounding material is accreted and the turbulent nature of
the gas causes the stars to move to lower density regions. We post-process the
impact of ionising radiation from the stars and find that ionising radiation is
not a limiting factor when considering SMS formation and growth. Rather the
birth environments are highly turbulent and a steady accretion flow is not
maintained within the timescale (2 Myr) of our simulations. As the massive
stars end their lives as direct collapse black holes this will seed these
embryonic haloes with a population of black holes with masses between
approximately 300 M$_{\odot}$ and 10,000 M$_{\odot}$. Afterwards they may sink
to the centre of the haloes, eventually coalescing to form larger intermediate
mass black holes whose in-situ mergers will be detectable by LISA.
