  Using the data from Gaia (ESA) Data Release 2 we performed the orbital
calculations of globular clusters (GCs) of the Milky Way. To explore possible
close encounters (or collisions) between the GCs, using our own developed
high-order phi-GRAPE code, we integrated backward and forward the orbits of 119
objects with reliable positions and proper motions. In calculations, we adopted
a realistic axisymmetric Galactic potential (bulge + disk + halo). Using
different impact conditions, we found four pairs of the six GCs that may have
experienced an encounter within twice the sum of the half-mass radii
(collisions) over the last 5Gyr: Terzan3 - NGC 6553, Terzan 3 - NGC 6218,
Liller 1 - NGC 6522 and Djorg 2 - NGC 6553.
