He died and left behind a mother, a father and a wife with whom he had not consummated the marriage

Firstly: 

Spouses become entitled to inherit from one another by virtue
of the marriage contract. If either spouse dies before the marriage has been
consummated, the other is entitled to inheritance. 

Al-Tirmidhi (1145) narrated from Ibn Mas’ood that he was
asked about a man who married a woman but he did not stipulate a dowry for
her and he did not consummate the marriage with her, then he died. Ibn
Mas’ood said:  She should be given a dowry like that of women who are
similar to her, no more and no less, and she has to observe the ‘iddah, and
she is entitled to the inheritance. Ma’qil ibn Sinaan al-Ashja’i stood up
and said: The Messenger of Allaah (peace and blessings of Allaah be
upon him) passed a ruling concerning Birwa’ bint Waashiq, one of our
womenfolk, that was like the ruling you have passed. Ibn Mas’ood was happy
with this (news). Classed as saheeh by al-Albaani in al-Irwa’, 1939. 

Ibn Qudaamah said in al-Mughni: 

With regard to
inheritance between spouses, it makes no difference whether that is before
or after consummation of the marriage, because of the general meaning of the
verse, and because the Prophet (peace and blessings of Allaah be upon
him) ruled that Birwa’ bint Waashiq be given the inheritance. Her husband
died before consummating the marriage with her, and he had not stipulated a
dowry for her. And because the marriage is valid and proven, and thus the
right of inheritance is given, just as it is after consummation. End quote. 

He also said: With regard
to the inheritance, there is no scholarly dispute concerning it, because
Allaah has allocated a share to each of the spouses, and the marriage
contract between the spouses in this case is valid and proven, and one may
inherit from the other because of it, because it comes under the general
meaning of the text. End quote. 

Secondly: 

With regard to the issue mentioned in the question, the
siblings do not inherit anything. The scholars are unanimously agreed that
siblings do not inherit if the father is present. 

See: al-Mughni, 9/6 

Thirdly: 

If there are two or more siblings, the mother gets one-sixth,
whether the siblings inherit or not, and whether they are male or female.
The evidence for that is the verse in which Allaah says (interpretation of
the meaning): 

“if the deceased left brothers or (sisters), the mother
has a sixth”

[al-Nisa’ 4:11] 

Shaykh Ibn ‘Uthaymeen
said in Tasheel al-Faraa’id (p. 33): 

The mother inherits
one-sixth if the deceased has descendents who are entitled to inherit, or if
he has a number of brothers or sisters, because Allaah says (interpretation
of the meaning): 

“For parents, a sixth share of inheritance to each if the
deceased left children; if no children, and the parents are the (only)
heirs, the mother has a third; if the deceased left brothers or (sisters),
the mother has a sixth”

[al-Nisa’ 4:11] 

It makes no difference if his siblings are male or female, or
both, whether they are full-siblings or half-siblings through the mother or
father, or whether they inherit or are prevented from inheriting by the
presence of the father, as is the apparent meaning of the verse, because
Allaah has allocated one-third to the mother if the father is present. Then
He says “if the deceased left brothers or (sisters), the mother has a
sixth”. The fa’ here (in the word fa in, translated here as “if”)
indicates that the second phrase is connected to the first and is based on
it. Siblings do not inherit if the father is present, but despite that the
mother is given one-sixth in this case. This is the view of the majority of
scholars. 

Shaykh al-Islam Ibn Taymiyah was of the view that they do not
decrease the share of the mother to one-sixth if they are denied inheritance
by the presence of the father. But this is contrary to the apparent meaning
of the verse. 

And he said in Nayl al-Ma’aarib (2/62): 

This ruling is proven
with regard to a brother or sister, and it makes no difference whether the
brother or sister who is reducing the share of the mother to one-sixth
inherits himself (or herself) or is deprived of inheritance by the presence
of the father. 

Fourthly: 

Based on this, in the case asked about here, the inheritance
is to be divided as follows: 

The wife gets one-quarter because her deceased husband has no
descendents who inherit from him. Allaah says (interpretation of the
meaning): 

“… their (your wives)
share is a fourth if you leave no child; but if you leave a child, they get
an eighth of that which you leave after payment of legacies that you may
have bequeathed or debts”

[al-Nisa’ 4:12] 

The mother takes
one-sixth because of the presence of a number of siblings. 

The father gets the rest of the estate, because the Prophet
(peace and blessings of Allaah be upon him) said: “Give the shares of
inheritance to those to whom they belong, and whatever is left is for the
closest male.” Narrated by al-Bukhaari, 6732; Muslim, 1615.  

So the estate should be divided into twelve equal shares,
three of which should be given to the wife, two to the mother, and the
remaining seven to the father. 

And Allaah knows best.