I found 2 isotopes in Wolfram database which are marked as unstable, but their lifetime is indicated as infinite (germanium-76 and selenium-82). The following chunck of code illustrates the issue:

g1 = Table[{{z, a}
     , IsotopeData[{z, a}, "BindingEnergy"]
     , IsotopeData[{z, a}, "Stable"]
     , IsotopeData[{z, a}, "Lifetime"]
     , IsotopeData[{z, a}, "FullSymbol"]
     , IsotopeData[{z, a}, "Name"]
     }, {z, 1, 118}, {a, 
     IsotopeData[#, "MassNumber"] & /@ IsotopeData[z]}] // 
   Flatten[#, 1] &;
g1 // Length

Select[g1, #1[[1]] == {32, 76} &]
Select[g1, #1[[1]] == {34, 82} &]

Is it an error of what?

  • 2
    $\begingroup$ I think these sorts of problems are best reported to Wolfram directly. $\endgroup$
    – Szabolcs
    Aug 19, 2019 at 13:03
  • $\begingroup$ Reporting it here won't do much. Send it to Wolfram (preferably with a reference) and they can fix it. $\endgroup$
    – ktm
    Aug 19, 2019 at 13:36
  • 3
    $\begingroup$ It's true that this site is not intended to documents bugs, BUT I think it's OK to ask if this is really a reproducible problem and not a corruption of one's system, or a OS dependent problem. Other people may benefit from knowing that some of the curated data is erroneous. Other previous Q&A documenting such problems and offering solutions have been well received. $\endgroup$
    – rhermans
    Aug 19, 2019 at 14:15
  • 1
    $\begingroup$ As it is shown in this post community.wolfram.com/groups/-/m/t/1766141, Wolfram ignores error reports on Isotope date\a although it is proved that thieir data base is outdated. $\endgroup$ Aug 19, 2019 at 14:44
  • 2
    $\begingroup$ That post was from two days ago - I don't know that no response over a weekend means Wolfram has "ignored" the report. However, it is a useful link and illustrates that there is likely an error in the data. I would highly recommend sending a bug report, even if someone else has already done so. It may move it up the list. $\endgroup$
    – Carl Lange
    Aug 19, 2019 at 14:48

2 Answers 2


These are extremely long-lived isotopes, decaying by the improbable double beta process, with half lives of billions of times the age of the universe. They're weird and exceptional, so it's not too surprising that the database isn't formally consistent here.


As noted in comments above, you would want to reach out to the curated data people at Wolfram if you have a question about content. The contact I have worked with in the past is Alan Joyce who is the Director of Content Development at Wolfram Alpha. Emails at Wolfram are structured as firstname + first letter of last name @wolfram.com.


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