There currently is one option to travel by night train from Mölndal (Sweden) to Hamburg (Germany), taking between approximately 10 and 11 hours: Namely the EN 345 operated by RDC.
RDC Euronight is a night train operated by RDC Deutschland connecting Berlin with Stockholm via Hamburg and Copenhagen, running three times a week in each direction.
Two sleeping car categories are available on board. The 1st class sleeper offers private compartments for up to three people with a private bathroom including shower and toilet; breakfast is included. The 2nd class sleeper has two-person compartments with a private washbasin and corridor toilets. These can be reserved privately or shared with other passengers in mixed or women-only compartments.
Couchette compartments accommodate up to six people and can be booked privately or as individual berths. All berths come with a pillow, sheet, and blanket. Washrooms and toilets are available in the carriage.
The seating car is the most affordable option, offering compartments for up to six people as well as open-plan carriages. Power sockets are available at every seat and a seat reservation is included in the ticket price. Toilets are located in the vestibules at the end of the car.
Passengers in sleeping car compartments — both 1st and 2nd class — receive breakfast delivered to their compartment. Couchette and seating car passengers are not provided with breakfast.