1,331. The Shiva Minyan
207:5 Shiva should be observed in the place where the deceased died because that's where the soul of the deceased will "mourn" and doing so would provide it with some comfort. It is a mitzvah to have a minyan for prayers there morning and evening. See 20:6 that we do not recite birkas kohanim (the priestly blessing in the repetition of Shemoneh Esrei) in a mourner's house. We hold the minyan even if the mourner isn't present because doing so provides consolation to the deceased. If there is a mourner, he joins the minyan. A Torah scroll should be brought in advance and placed in an appropriate spot in anticipation of the services that will be held there. If there are deceased people in two houses, one of which has a mourner and the other of which doesn't, and there aren't enough people in town to make two minyanim, they should pray in the house without a mourner.
The accepted practice is to recite Psalm 49 in the deceased's house after each prayer service. There's an excellent practice to study Mishna there in order to elevate the soul. In Hebrew, "Mishna" is an anagram of "neshama" - soul.
207:6 Hallel is not recited in the deceased's home if there is a mourner there during shiva because it is like mocking the dead since it includes the phrase "the dead cannot praise G-d" (Psalms 115:17). If possible, the mourner should go in another room and the rest of the minyan says Hallel. If no other room is available then on Rosh Chodesh, they don't need to recite Hallel later at home but on Chanukah they do. If they are davening in the deceased's home and no mourner is present, or if they are in a mourner's home that was not the deceased's home, they also say Hallel on Rosh Chodesh but the mourner doesn't join them. This is because Hallel includes the phrase "This is the day that G-d has made, let us be glad and rejoice on it" (Psalms 118:24). If the last day of shiva is on Chanukah, then the mourners recite Hallel after they get up from shiva because they are now obligated. Some authorities say that we do recite Hallel on Chanukah in a mourner's home if there is a minyan. If Rosh Chodesh falls on Shabbos, Hallel is recited with a minyan in a mourner's home because there is no public mourning on Shabbos.