Tag category Chem_shift_ref
Key tags (columns):
Tags in table Chem_shift_ref:
| Tag | Description | data type | Mandatory |
|---|---|---|---|
| Atom_group | Group of atoms within a molecule whose chemical shift was used as the standard chemical shift reference for the defined observed nuclei. | line | yes |
| Atom_isotope_number | The mass number for the chemical element defined by the tag '_Atom_type' or any of its related tags. | int | yes |
| Atom_type | The value for this tag is a standard IUPAC abbreviation for an element (i.e. H C P etc). | code | yes |
| Chem_shift_reference_ID | Pointer to '_Chem_shift_reference.ID' | int | yes |
| Chem_shift_units | Units for the chemical shift value assigned to the atoms of the chemical shift reference. | line | yes |
| Chem_shift_val | Value assigned to the chemical shift of the reference compound. | float | yes |
| Concentration_units | Units for the concentration value for the chemical shift reference compound. | code | |
| Concentration_val | Concentration of the chemical shift reference compound in the external reference sample. | float | |
| Correction_val | An uniform correction value that was applied because of an extenuating circumstance such as data collection at an unusual temperature. | float | |
| Correction_val_cit_ID | Pointer to '_Citation.ID' | int | |
| Correction_val_cit_label | Pointer to a save frame of the category citation. | framecode | |
| Entry_ID | Pointer to '_Entry.ID' | code | yes |
| External_ref_axis | The axis of the external chemical shift reference sample relative to the static field (Bo) of the spectrometer. | line | |
| External_ref_loc | External chemical shift references are defined as either located within the sample (e.g. as a capillary) or external to the sample and are inserted into the spectrometer before after or both before and after the sample containing the molecular system s | line | |
| External_ref_sample_geometry | The geometrical shape of the external reference sample. | line | |
| Indirect_shift_ratio | The Chi value used in calculating the chemical shift referencing values for nuclei that are referenced indirectly. The values used should be those recommended by the IUPAC Taskforce on the deposition of data to the public databases (Markley et al. Pure | float | |
| Indirect_shift_ratio_cit_ID | Pointer to '_Citation.ID' | int | |
| Indirect_shift_ratio_cit_label | Pointer to a save frame of the category citation. | framecode | |
| Mol_common_name | Common name or abbreviation used in the literature for the molecule used as a chemical shift reference. | line | yes |
| Rank | The rank of the chemical shift reference. A primary reference is the one used in reporting the data. A secondary reference would be the compound in the sample or used as an external reference. | code | |
| Ref_correction_type | If a correction value is applied to calculate the reported chemical shifts the source of the correction (pH; temperature; etc.). | line | |
| Ref_method | The chemical shift reference may be either internal (the compound is located in the sample) or external (the compound is in a container external to the sample). | line | |
| Ref_type | The reference type may be either direct (against a value measured with a chemical compound) or indirect (calculated from chemical shift ratios). | line | |
| Sf_ID | Pointer to '_Chem_shift_reference.Sf_ID' | int | yes |
| Solvent | Solvent used for the external reference sample. | line | |