The reference composition of the Sun published in Asplund, Grevesse, Sauval & Scott (2009, Ann. Rev. Astron. & Astrophys. 47:481, arXiv:0909.0948) is available here. Below you can also find links to machine-readable ASCII versions of the two most important tables.

Table 1
Present-day solar photospheric elemental abundances, and CI meteoritic abundances. To obtain bulk/protosolar abundances, add 0.05 dex for He, 0.04 dex for heavier elements.

Table 3
Present-day representative solar isotopic composition.

An obligatory note from Annual Reviews on the above link to the paper: "This complimentary one-time access to this Annual Reviews article as a PDF file is for your own personal use. Any further/multiple distribution, publication, or commercial usage of this copyrighted material requires submission of a permission request addressed to the Annual Reviews Permissions Department.