##### Core dictionary (coreCIF) version 2.3.1

# _refine_ls_R_factor_obs

**Name:**

`'_refine_ls_R_factor_obs'`

This definition has been superseded and is
retained here only for archival purposes. Use instead
`'_refine_ls_R_factor_gt'`

**Definition:**

Residual factor for the reflections classified as 'observed' (see _reflns_observed_criterion) and included in the refinement. The reflections also satisfy the resolution limits established by _refine_ls_d_res_high and _refine_ls_d_res_low. This is the conventional R factor. See also _refine_ls_wR_factor_ definitions. sum | F(obs) - F(calc) | R = ------------------------ sum | F(obs) | F(obs) = the observed structure-factor amplitudes F(calc) = the calculated structure-factor amplitudes and the sum is taken over the specified reflections

The permitted range is 0.0 -> infinity

**Related item: **

**Type:** numb

**Category:** refine