By plane: 

Aeropuerto Internacional de Guanajuato (BJX)  is an international airport located in Silao, Guanajuato. It handles national and international air traffic of the area that includes the city of León and the state capital, Guanajuato. Both CIMAT and/or hotels in Guanajuato are a 30-45 minute taxi ride from the airport.

By bus:

From Mexico City, in the Terminal Central del Norte there are several companies that service the route Mexico City - Guanajuato, for example, ETN, Omnibus de Mexico, Primera Plus.

By car:

From Mexico City, the approximate distance is 360km, with an average travel time of 4 hours. You can find more information here: SCT (English) Traza tu ruta (Spanish)

CIMAT is located near the mine Mineral de Valenciana in the city of Guanajuato.