8FUNCTIONS: diastereotopic - CYANA function

Synopsis: diastereotopic(<integer>) = <integer>

Function that returns the index of the first atom of the n-th
diastereotopic pair in the grid search fragment defined by the most
recent 'grid fragment' command, where n is the integer argument of
the function. The function returns 0 for arguments n larger than the
number of diastereotopic pairs in the current grid search fragment.
