**Definition:**

The occupational distortion of a given atom or rigid group is usually parameterized by Fourier series. Each term of the series commonly adopts two different representations: the sine-cosine form, Pc cos(2\p k r)+Ps sin(2\p k r), and the modulus-argument form, |P| cos(2\p k r+\d), where k is the wave vector of the term and r is the atomic average position. _atom_site_occ_Fourier_param_modulus is the modulus (|P|) of the complex amplitude corresponding to the Fourier term defined by _atom_site_occ_Fourier_atom_site_label and _atom_site_occ_Fourier_wave_vector_seq_id.

Appears in list containing _atom_site_occ_Fourier_param_id

The permitted range is 0.0 -> infinity

Enumeration default: 0.0

**Type:** numb

**Category:** atom_site_occ_Fourier_param

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