There currently is one option to travel by night train from Mölndal (Sweden) to Padborg (Denmark), taking between approximately 7 and 8 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.
The couchette car has compartments for up to six people, bookable as a private compartment or as individual berths. Each berth includes a pillow, sheet, and blanket. Seats convert into berths for the night. Washrooms and toilets are available in the car.
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.