How to reach the MPI-P by plane

Frankfurt International Airport (IATA code: FRA)

At Frankfurt airport there are two train stations:

the regional (local) station in the basement ("level-1") of terminal 1 (area "S")
the long distance station, AirRail Terminal or area "T"

AirRail Terminal
The AirRail Terminal is directly accessible from Terminal 1 (Hall A,B,C). From Terminal 2 (Hall D and E) both train stations are reached via Terminal 1: either take the Sky Line train or the free shuttle bus.
There is a Deutsche Bahn ("DB") counter at the ground level of Terminal 1 and at the top of the long-distance station, and a travel agency ("Reisebüro") at arrival level of Hall B.

From the station for regional trains:
From the regional station, direct local trains (RE and S-Bahn "S8") with final destination Wiesbaden) frequently leave from track 3 for Mainz Hbf, which is reached in 20-30 minutes.

You have to buy a Verkehrsverbund ticket (at "RMV" vending machines) in advance for € 4.65. (The code number for Mainz is 6511; do not opt for a connection via Frankfurt Hbf).
There is no possibility to buy tickets on the trains and not having a valid ticket carries a € 60 fine.
A "RMV" vending machine is also located in the baggage claim area of Hall B.
Please note: S9 does not go to Mainz Hbf so you have to change trains at "Mainz-Kastel". In front of this station (on the other side of the street) you can take the busses Nº 54, 55 or 58. On weekdays during day time you can also catch a regional train at Mainz-Bischofsheim that takes you to Mainz Hbf.

From the long-distance train station:
From the long-distance station (track 6 and 7) non-stop IC-/EC-/ICE- trains take you to Mainz Hbf in ca. 20 minutes.
The regular fare is € 9.00 (IC/EC) and € 13.00 (ICE). Tickets can be bought at "DB" vending machines and counters, or on the train at some additional charge. There is approximately one train per hour heading for Mainz Hbf (usually leaving 58 minutes past the hour).

Frankfurt Hahn Airport (IATA code: HHN)

Note, there is another international airport, Frankfurt-Hahn, which is located in Hunsrück, some 70 km west of Mainz.
Between Mainz Hbf and that airport there are several direct bus connections ('BOHR' bus company). The travel time is 70 minutes and the fare costs € 15,00. The buses stop at Mainz central station platform N.