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International
Tables for Crystallography Volume G Definition and exchange of crystallographic data Edited by J. R. Hester and B. McMahon © International Union of Crystallography 2026 |
International Tables for Crystallography (2026). Vol. G. Early view chapter
https://doi.org/10.1107/97809553602060001011 Chapter 4.2 Core dictionary (coreCIF) |
Core dictionary version 3.3.0
_refln.F_complex
Name:_refln.F_complex
Alias:
_refln_F_complex
Definition:
The structure-factor vector for the reflection calculated from
the atom site data.
Type: Complex
Definition method:
If (_diffrn_radiation.probe == "neutron")
_units.code = "femtometres"
Else If (_diffrn_radiation.probe == "electron")
_units.code = "volts"
Else _units.code = "electrons"
Evaluation method:
With r as refln
fc = Complex (0., 0.)
h = r.hkl
Loop a as atom_site {
f = a.site_symmetry_multiplicity * a.occupancy * (
r.form_factor_table [a.type_symbol] +
_atom_type_scat[a.type_symbol].dispersion )
Loop s as space_group_symop {
t = Exp(-h * s.R * a.matrix_beta * s.RT * h)
fc += f * t * ExpImag(TwoPi *( h *( s.R * a.fract_xyz + s.T)))
} }
_refln.F_complex = fc / _space_group.multiplicity
Category:
refln
