XmlmmCIF equivalent: cell Data items in the CELL category record details about the crystallographic cell parameters. XmlmmCIF equivalent: cell/Z_PDB The number of the polymeric chains in a unit cell. In the case of heteropolymers, Z is the number of occurrences of the most populous chain. This data item is provided for compatibility with the original Protein Data Bank format, and only for that purpose. XmlmmCIF equivalent: cell/angle_alpha Unit-cell angle alpha in degrees of the reported structure. XmlmmCIF equivalent: cell/angle_alpha_esd The estimated standard deviation of _cell.angle_alpha. XmlmmCIF equivalent: cell/angle_beta Unit-cell angle beta in degrees of the reported structure. XmlmmCIF equivalent: cell/angle_beta_esd The estimated standard deviation of _cell.angle_beta. XmlmmCIF equivalent: cell/angle_gamma Unit-cell angle gamma in degrees of the reported structure. XmlmmCIF equivalent: cell/angle_gamma_esd The estimated standard deviation of _cell.angle_gamma. XmlmmCIF equivalent: cell/details A description of special aspects of the cell choice, noting possible alternative settings. XmlmmCIF equivalent: cell/formula_units_Z The number of the formula units in the unit cell as specified by _chemical_formula.structural, _chemical_formula.moiety or _chemical_formula.sum. XmlmmCIF equivalent: cell/length_a Unit-cell length a corresponding to the structure reported. XmlmmCIF equivalent: cell/length_a_esd The estimated standard deviation of _cell.length_a. XmlmmCIF equivalent: cell/length_b Unit-cell length b corresponding to the structure reported. XmlmmCIF equivalent: cell/length_b_esd The estimated standard deviation of _cell.length_b. XmlmmCIF equivalent: cell/length_c Unit-cell length c corresponding to the structure reported. XmlmmCIF equivalent: cell/length_c_esd The estimated standard deviation of _cell.length_c. XmlmmCIF equivalent: cell/pdbx_unique_axis To further identify unique axis if necessary. E.g., P 21 with an unique C axis will have 'C' in this field. XmlmmCIF equivalent: cell/volume Cell volume V in angstroms cubed. V = a b c (1 - cos^2^~alpha~ - cos^2^~beta~ - cos^2^~gamma~ + 2 cos~alpha~ cos~beta~ cos~gamma~)^1/2^ a = _cell.length_a b = _cell.length_b c = _cell.length_c alpha = _cell.angle_alpha beta = _cell.angle_beta gamma = _cell.angle_gamma XmlmmCIF equivalent: cell/volume_esd The estimated standard deviation of _cell.volume. XmlmmCIF equivalent: cell/entry_id This data item is a pointer to _entry.id in the ENTRY category.