Did you try to search them at http://www.crystallography.net/

Hope it helps.

Typically you use the datasets for pure Ti and simulate the change in lattice parameter by the alloying elements an plot the peaks. If you have experimental data, you could use freeware like CMPR or fullprof to do so. 

In addition, a lot of literature exists, e.g., there is some X-ray data availiable in "In situ observations of lattice expansion and transformation rates of α and β phases in Ti–6Al–4V", Materials Science and Engineering: A, Volume 391, Issues 1–2, 25 January 2005, Pages 104–113.

Thank you for your answers.

here: http://materials.springer.com/isp/crystallographic/docs/sd_1931746

but it's not free... :(

it's not possible to get that one, I need that one also

Do you get the cif of Ti-6Al-4V？