Files with SCHAKAL extension can be found as chemical data files for SHAKAL program by E.Keller.
SCHAKAL file extension - Schakal chemical modeller input file
What is schakal file? How to open schakal files?
File type specification:
The SCHAKAL file extension is related to SCHAKAL, a FORTRAN program for the graphical representation of molecular and solid-state structure models, written by E. Keller. These *.schakal files contain chemical modeller input data.