There is a double-complex version of each complex built-in function. Generally, the specific function names begin with Z or CD instead of C, except for the two functions, DIMAG and DREAL, which return a real value. Examples are: SIN(), CSIN(), CDSIN().
Example: Double-complex scalars and arrays:
DOUBLE COMPLEX U, V DOUBLE COMPLEX W(3,6) COMPLEX*16 X, Y(5,5) COMPLEX U*16(5), V(5)*16