XmlmmCIF equivalent: chem_comp_atom Data items in the CHEM_COMP_ATOM category record details about the atoms in a chemical component. Atomic coordinates can be given for the components; specifying coordinates is an alternative to specifying the structure of the component via bonds, angles, planes, etc., in the appropriate CHEM_COMP subcategories. XmlmmCIF equivalent: chem_comp_atom/alt_atom_id An alternative identifier for the atom. This data item would be used in cases where alternative nomenclatures exist for labeling atoms in a group. XmlmmCIF equivalent: chem_comp_atom/charge The net integer charge assigned to this atom. This is the formal charge assignment normally found in chemical diagrams. XmlmmCIF equivalent: chem_comp_atom/model_Cartn_x The x component of the coordinates for this atom in this component specified as orthogonal angstroms. The choice of reference axis frame for the coordinates is arbitrary. The set of coordinates input for the entity here is intended to correspond to the atomic model used to generate restraints for structure refinement, and not to atom sites in the _atom_site list. XmlmmCIF equivalent: chem_comp_atom/model_Cartn_x_esd The estimated standard deviation of _chem_comp_atom.model_Cartn_x. XmlmmCIF equivalent: chem_comp_atom/model_Cartn_y The y component of the coordinates for this atom in this component specified as orthogonal angstroms. The choice of reference axis frame for the coordinates is arbitrary. The set of coordinates input for the entity here is intended to correspond to the atomic model used to generate restraints for structure refinement, and not to atom sites in the _atom_site list. XmlmmCIF equivalent: chem_comp_atom/model_Cartn_y_esd The estimated standard deviation of _chem_comp_atom.model_Cartn_y. XmlmmCIF equivalent: chem_comp_atom/model_Cartn_z The x component of the coordinates for this atom in this component specified as orthogonal angstroms. The choice of reference axis frame for the coordinates is arbitrary. The set of coordinates input for the entity here is intended to correspond to the atomic model used to generate restraints for structure refinement, and not to atom sites in the _atom_site list. XmlmmCIF equivalent: chem_comp_atom/model_Cartn_z_esd The estimated standard deviation of _chem_comp_atom.model_Cartn_z. XmlmmCIF equivalent: chem_comp_atom/partial_charge The partial charge assigned to this atom. XmlmmCIF equivalent: chem_comp_atom/substruct_code This data item assigns the atom to a substructure of the component, if appropriate. XmlmmCIF equivalent: chem_comp_atom/type_symbol This data item is a pointer to _atom_type.symbol in the ATOM_TYPE category. XmlmmCIF equivalent: chem_comp_atom/comp_id This data item is a pointer to _chem_comp.id in the CHEM_COMP category. XmlmmCIF equivalent: chem_comp_atom/atom_id The value of _chem_comp_atom.atom_id must uniquely identify each atom in each monomer in the CHEM_COMP_ATOM list. The atom identifiers need not be unique over all atoms in the data block; they need only be unique for each atom in a component. Note that this item need not be a number; it can be any unique identifier.