_T1.Atom_isotope_number
| Description | The mass number for the chemical element defined by the tag '_Atom_type' or any of its related tags. |
| Details: | |
| Parent saveframe | heteronucl_T1_relaxation |
| Data type | int |
| DB table | T1 |
| DB column | Atom_isotope_number |
| DB type | INTEGER |
| NULL allowed | yes |