search

lmmentel / mendeleev

A python package for accessing various properties of elements, ions and isotopes in the periodic table of elements.
https://mendeleev.readthedocs.io
MIT License
220 stars 40 forks source link

Natural abundances for Te126 and Ta180 are incorrect #122

Closed paulromano closed 1 year ago

paulromano commented 1 year ago

Describe the bug

The natural abundance of Te126 as given in IUPAC 2013 is 18.84%, whereas mendeleev reports it to be 8.84%.

The natural abundance of Ta180 as given in IUPAC 2013 is 0.01201%, whereas mendeleev reports no value.

To Reproduce

from mendeleev import isotope
print(isotope(52, 126).abundance)
print(isotope(73, 180).abundance)

Expected behavior

isotope(52, 126).abundance should give 18.84, and isotope(73, 180).abundance should give 0.01201.

Specification

lmmentel commented 1 year ago

Good catch!

Do you have a data source for the values you are mentioning. I took the isotope data from this file provided by Nuclear Data Services.

I checked again and for 126Tc the abundance (given in the IS= field) is 8.84, here's the actual data from the source file:

126 0520   126Te  -90064.2        1.4                                 stbl              0+            03          1924 IS=8.84 25

I also checked the abundance for 180Ta and indeed it's missing from this source (missing IS= field):

180 0730   180Ta  -48933.6        2.1                                   8.154  h 0.006  1+            15          1938 EC=85 3;B-=15 3

It could be that the data in this source is outdated or contains errors but I would like to investigate the source you mention first to compare. Could you share where the values are coming from?

paulromano commented 1 year ago

I was looking at data from here. It looks like this is an updated revision of the same file, and from a quick diff on them the only thing that is different is the one line for Te126.

You're right that IS is missing on 180Ta. If you look at the following line, it appears that it is actually the first metastable state of 180Ta that is stable and has an abundance associated with it. Not sure if there's any clean way of handling that!

lmmentel commented 1 year ago

Hey I compared the source you provided with the original and indeed the only change made is abundance for 126Te. Should be fixed in #123 . Thanks again!