Calculate a vibrational scaling factorEnter Formula(s) or choose by chemical groups.
Rules for chemical formula
- Enter a sequence of element symbols followed by numbers to specify the amounts of desired elements (e.g., C6H6).
- Elements may be in any order.
- If only one of a given atom is desired, you may omit the number after the element symbol.
- Parentheses may be used to group atoms.
- Multiple specifications for an atom will be added. This means that CH3(CH2)4CH3 will be treated the same as C6H14.
- A comma delimited list of several species may be entered.
- Ions are indicated by placing + or - at the end of the formula (CH3+, BF4-, CO3--)
Species in the CCCBDB
- Mostly atoms with atomic number less than than 36 (Krypton), except for most of the transition metals. See section I.B.1 for a periodic table view.
- Six or fewer heavy atoms and twenty or fewer total atoms. Exception: Versions 8 and higher have a few substituted benzenes with more than six heavy atoms. Versions 12 and higher have bromine-containing molecules.
Going to the group selection page allows the selection of molecules with certain chemical groups, such as C=O bonds or NH2 groups or molecules that contain phosphorus. A list of species that match the group criteria is returned and one or more may be selected.
Experimental vibrational frequencies are not present for all species in the database. Only species with experimental vibrational frequencies will be used to compute the least-squares best scaling factor.