isotopes in elemental analysis

User 870ab5b546

12-09-2005 16:41:11

The elemental analysis plug-in is inconsistent regarding isotopes. I drew a structure C12H19D2NO4, and it told me the formula was C12H21NO4, but it calculated the mass correctly (245). The formula should be displayed with the isotopes explicitly indicated.

ChemAxon d76e6e95eb

12-09-2005 17:52:17

The Elemental Analysis plugin supports both approaches. The "formula" function returnes the elemental formula without separating the isotopes. The "iformula" function however separates the isotopes. You can test them with the command line cxcalc tool:

$ cxcalc "[2H]OCCC" formula

id Formula

1 C3H8O

$ cxcalc "[2H]OCCC" iformula

id Isotope formula

1 C3H7[2H]O

Not all functions of the Elemental Analysis plugin is available through the Marvin GUI, but you can access them via the API an the cxcalc command line tool. If you need it in the GUI as well we can add it.

User 870ab5b546

12-09-2005 18:04:12

The iformula option should be the default in the Marvin GUI. If someone goes to the trouble of specifying isotopes in their drawing, they are doing so for a reason.

ChemAxon d76e6e95eb

13-09-2005 12:49:10

We will display both the isotope formula and the isotope composition functions on the Elemental Analysis plugin dialog, additionally to the current ones.