This quantity is measured for an NCE ligand (“LIG-und”) to determine the state of spin-crossover iron complexes, since it increases by 10 percent upon excitation. The Fourier (“FOR-ee-ay”) transform of the gas-phase molecular intensity curve is a histogram plotting this quantity, which is also the first peak in a crystal’s pair distribution function. It’s not a reaction rate, but due to trans influence, this quantity increases for ligands opposite sigma acceptors in square planar complexes. Mono·clinic crystals have three different values for this quantity labeled a, (-5[1])b, and c. (10[2])Without pseudo·rotation, this quantity is greater for apical (10[1])than equatorial (10[1])ligands (-5[1])in trigonal bi·pyramidal (10[1])complexes. (10[2])Conversely, (10[1])two distinct values for this quantity (10[1])are measured on octa·hedral copper complexes (10[1]-5[1])because of a Jahn (“yahn”)–Teller distortion. (10[3]) For 10 points, a crystal’s lattice (-5[1])constant is analogous to what quantity, which is usually about an (10[4])angstrom? (10[5]0[4])■END■