All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
We do not know any evidence from the Book of Allaah, the Sunnah of the Prophet or the sayings of our righteous predecessors about reading Al-Faatihah (the opening chapter of the Quran) after a supplication or after making a remembrance, so one should avoid doing so lest he would be indulging in an innovation.
The Permanent Committee for Fatwa and Scientific Research in Saudi Arabia authoritatively determined in a Fatwa that reading chapter Al-Faatihah after a supplication is an innovation, the text of this Fatwa is as follows: "It is not confirmed that the Prophet used to recite chapter Al-Faatihah after a supplication according to our knowledge, so reading it after a supplication is an innovation."
Similarly, we do not know any evidence from the Book of Allaah, the Sunnah of the Prophet or our righteous predecessors about reading Al-Faatihah when expressing condolence or when visiting the relatives of the dead. The Prophet said: "Whoever performs a (religious) deed that is not in accordance with our way, it will be rejected." [Al-Bukhari and Muslim]
In another narration: "If somebody introduces into this faith of ours (Islam) something, which is not a part of it, it will be rejected."
Therefore, a Muslim should be keen to follow the Sunnah and avoid innovations because any innovation is a misguidance as confirmed by the Prophet .
For more benefit, please refer to Fatwa 85808 about the ruling of gathering in the deceased's house for condolences.
Allaah Knows best.