Will the Unsaved Change Their Minds After They Die?

According to Luke 16.31 a person won't change his mind after he dies. Even the Rich Man in the bad side of Hades did not change his mind. He was not asking for forgiveness because he now accepts Jesus. He was asking for the torment to lessen and to try to convince those people in his life by some vague works-based salvation, but he himself still rejected the Lord and always would.

Luk 16:19 There was a certain rich man, which was clothed in purple and fine linen, and fared sumptuously every day:
Luk 16:20 And there was a certain beggar named Lazarus, which was laid at his gate, full of sores,
Luk 16:21 And desiring to be fed with the crumbs which fell from the rich man's table: moreover the dogs came and licked his sores.
Luk 16:22 And it came to pass, that the beggar died, and was carried by the angels into Abraham's bosom: the rich man also died, and was buried;
Luk 16:23 And in hades he lift up his eyes, being in torments, and seeth Abraham afar off, and Lazarus in his bosom.
Luk 16:24 And he cried and said, Father Abraham, have mercy on me, and send Lazarus, that he may dip the tip of his finger in water, and cool my tongue; for I am tormented in this flame.
Luk 16:25 But Abraham said, Son, remember that thou in thy lifetime receivedst thy good things, and likewise Lazarus evil things: but now he is comforted, and thou art tormented.
Luk 16:26 And beside all this, between us and you there is a great gulf fixed: so that they which would pass from hence to you cannot; neither can they pass to us, that [would come] from thence.
Luk 16:27 Then he said, I pray thee therefore, father, that thou wouldest send him to my father's house:
Luk 16:28 For I have five brethren; that he may testify unto them, lest they also come into this place of torment.
Luk 16:29 Abraham saith unto him, They have Moses and the prophets; let them hear them.
Luk 16:30 And he said, Nay, father Abraham: but if one went unto them from the dead, they will repent.
Luk 16:31 And he said unto him, If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.

I think, if anything in time they will grow to hate God because of where they are.

Don't they already hate God? since they have been thrown into the bad side of Hades (that's why God put them there according to their free-choice) to await to be resurrected at the Great White Throne to be judged and sentenced to Hell for eternity. After all they want to be eternally separated by God so God gives them what they want. What this passage tells me is that they may not necessarily want the suffering but that they would prefer to have it than be with God in the New City and New Earth.

To accept blame is something I don't think they will do. Not all who don't have the faith hate God, some may think they can get by on their own efforts,of course they would be wrong.

It is not only by their own efforts, but they want to be eternally separated from God. That's hate.