Installed Nominatim but error

[mmhrishi]

I have installed nominatim but error gets for connecting to DB,i run even the import and it worked,but cannot see interface.any help
string(19) "pgsql://@/nominatim" object(DB_Error)#2 (8) { ["error_message_prefix"]=> string(0) "" ["mode"]=> int(1) ["level"]=> int(1024) ["code"]=> int(-24) ["message"]=> string(24) "DB Error: connect failed" ["userinfo"]=> string(239) " [nativecode=pg_connect(): Unable to connect to PostgreSQL server: could not connect to server: Permission denied Is the server running locally and accepting connections on Unix domain socket "/tmp/.s.PGSQL.5432"?] **