All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If the deceased did not leave any other heirs except those mentioned in the question, then his wife gets one fourth as a fixed inheritance because there are no direct offspring as heirs (who are entitled to inherit) as Allah Says (what means): {And for them [i.e. the wives] is one fourth if you leave no child.} [Quran 4:12]
The remainder should be divided amongst the two full-sisters and the full-brothers by Ta’seeb (by virtue of having a paternal relation with the deceased and not having a fixed share, so they get what is left after the fixed shares have been distributed); the male twice the share of the female, as Allah Says (what means): {If there are both brothers and sisters, the male will have the share of two females.} [Quran 4:176]
However, the two half-sisters from the father’s side and the nephews (sons of the brother) do not get anything from the inheritance because they are prevented by the existence of the brother.
Therefore, the inheritance should be divided into 16 shares, the wife of the deceased gets one-fourth, which is 4 shares, each full-brother gets 2 shares, and each full-sister gets 1 share.
Allah knows best.