Robin Thicke is waving the white flag … telling people in his camp his marriage to Paula Patton has collapsed.

Thicke certainly gave a strong sign the union is over by listing his L.A. home Monday. Paula has not lived in the house since their separation in February, after that grab-ass pic became public.

Sources connected with Robin tell TMZ … an attorney is already working on a financial settlement — separating assets.

Our sources say, however, neither side has hired a divorce lawyer.

Thicke is saying he will NOT be the one who files for divorce … she’ll have to do it. But he says he’s done begging and is moving on.