Indicate whether each of the following descriptions better applies to the determination of atomic structure of proteins by x-ray diffraction (X) or by nuclear magnetic resonance (NMR) spectroscopy (N). Your answer would be a five-letter string composed of letters X and N only, e.g. NNXNN.
( ) It is more suitable for complexes larger than about 100 kD.
( ) It requires samples to crystallize.
( ) It can better reveal dynamics of molecular motions.
( ) It involves the calculation of electron-density maps.
( ) It is used to determine the solution structure of proteins.