have not yet come to terms with his passing

アーロン・シュワルツ氏が亡くなりました。２６歳の若さです。

come to termsはご存知のとおり、「合意に達する」（『ジーニアス英和辞典　第４版』大修館）という意味ですね。ここでは「受け入れる」の訳がすんなりいくと思います。
ご遺族のコメントのように"have not yet come to terms with his passing"とすれば、「まだ彼の死を受け入れることができない」という表現ができます。自分の頭の中の単語帳に詰め込んで、スラスラ言えるようになりたいです。使う機会はない方が良いのですが。(Minnesota)

(CNN) -- Aaron Swartz, an Internet savant who at a young age shaped the online era by co-developing RSS and Reddit and later became a digital activist, has committed suicide.

Swartz's body was found Friday evening in Brooklyn, said Ellen Borakove, a spokeswoman with the New York medical examiner's office. The 26-year-old had hanged himself in his apartment.

His family and partner said they were "in shock, and have not yet come to terms with his passing."

http://edition.cnn.com/2013/01/12/us/new-york-reddit-founder-suicide/index.html?iref=allsearch