How do the basis sets get assigned to the atoms in my input deck?
The tags associated with atoms (e.g. H, H1, Hydrogen) are mapped to the tags used in the basis set definitions by: • If there is an exact match, then use it E.g., if H1 appears in both the geometry and the basis, then the H1 basis set is used. • If there is not an exact match, then if there is a basis set defined for that element, then use it E.g., if H1 appears in the geometry but not in the basis, then try to use a basis set for H or for Hydrogen. It will not try to match another tag such as H2 in the basis set. • If two definitions are given for an element in the basis set, then use the definition such that the basis set tag is completely matched (or is a substring) of the geometry tag. E.g., if H1, Hydrogen1, and Hydro1 appear in the geometry and H and Hydrogen appear in the basis, H1 will map to H, Hydrogen1 will map to Hydrogen, and Hydro1 will map to H. You are STRONGLY advised not to do perverse inputs such as Hydro1 which can only cause confusion.