In post 23.4, we saw that the interpretation of x-ray diffraction patterns from crystals involves a temperature factor because atoms are displaced from their ideal lattice points by thermal vibrations. We have seen that heat is kinetic energy of atomic molecular motion (post 16.35). In a crystalline solid, the atoms must be oscillating about their… Continue reading 24.2 Thermal vibration of an atom in a crystal: the temperature factor in x-ray crystallography

I am going to calculate the Fourier transform of a Gaussian function because I want to use the result in a later post. I can define the Gaussian function, g(x) as an exponential function of the form g(x) = exp(-ax2). Here, exp(y) is another way of writing ey where e a number with the approximate… Continue reading 24.1 Fourier transform of a Gaussian function