COMPLEX(16) (same as COMPLEX(KIND=16) or COMPLEX*32) data is 32 contiguous bytes containing a pair of REAL(16) values stored in IEEE-style X_floating format. The low-order 16 bytes contain REAL(16) data that represents the real part of the complex data. The high-order 16 bytes contain REAL(8) data that represents the imaginary part of the complex data, as shown below.

The limits and underflow characteristics for REAL(16) apply to the two separate real and imaginary parts of a COMPLEX(16) number. Like REAL(16) numbers, the sign bit representation is 0 (zero) for positive numbers and 1 for negative numbers.