Osmium: isotope data

Osmium isotopes are used for the production of radioisotopes and in scientific experiments. Os-192 can be used for the production of the medical radioisotope Pt-195m. Os-184 is used for the production of the radioisotope Os-185. Os-191 can be used for the production of the radioisotopes Os-192. Os-190 has been used as a tracer to determine Os abundance in meteorites using isotope dilution ICP-MS. Finally, Os-189 has been used to experiment with nuclear excitation by electronic transition.

Naturally occurring isotopes

This table shows information about naturally occuring isotopes, their atomic masses, their natural abundances, their nuclear spins, and their magnetic moments. Further data for radioisotopes (radioactive isotopes) of osmium are listed (including any which occur naturally) below.
Isotope Mass / Da Natural abundance (atom %) Nuclear spin (I) Magnetic moment (μ/μN)
184Os 183.952488 (4) 0.02 (1) 0
186Os 185.953830 (4) 1.59 (3) 0
187Os 186.955741 (3) 1.96 (2) 1/2 0.06465185
188Os 187.955830 (3) 13.24 (8) 0
189Os 188.958137 (4) 16.15 (5) 3/2 0.659933
190Os 189.958436 (4) 26.26 (2) 0
192Os 191.961467 (4) 40.78 (19) 0

In the above, the most intense ion is set to 100% since this corresponds best to the output from a mass spectrometer. This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes.

Radiosotope data

Further data for naturally occuring isotopes of osmium are listed above. This table gives information about some radiosotopes of osmium, their masses, their half-lives, their modes of decay, their nuclear spins, and their nuclear magnetic moments.
Isotope Mass / Da Half-life Mode of decay Nuclear spin Nuclear magnetic moment
182Os 181.95219 21.5 h EC to 182Re 0
183Os 182.9531 13 h EC to 183Re 9/2
185Os 184.954043 93.6 d EC to 185Re 1/2
191Os 190.960928 15.4 d β- to 191Ir 9/2
193Os 192.964138 30.5 h β- to 193Ir 3/2 0.73
194Os 193.965179 6.0 y β- to 194Ir 0

Sheffield ChemPuter isotope pattern calculator

You can use WebElements to calculate an isotope pattern for an arbitrary chemical formula:

Edit this formula :

Note the following when entering your formula:

  • Correctly nested brackets [{()}] are OK
  • 'Pseudoelements' such as Me, Ph, Cp, and many others are OK
  • Compound names and element names such as 'water' or 'manganese' are not OK
  • Experiment with your formula to see what is possible


  1. Naturally occurring isotope abundances: Commission on Atomic Weights and Isotopic Abundances report for the International Union of Pure and Applied Chemistry in Isotopic Compositions of the Elements 1989, Pure and Applied Chemistry, 1998, 70, 217. [Copyright 1998 IUPAC]
  2. For further information about radioisotopes see Jonghwa Chang's (Korea Atomic Energy Research Institute) Table of the Nuclides
  3. Masses, nuclear spins, and magnetic moments: I. Mills, T. Cvitas, K. Homann, N. Kallay, and K. Kuchitsu in Quantities, Units and Symbols in Physical Chemistry, Blackwell Scientific Publications, Oxford, UK, 1988. [Copyright 1988 IUPAC]

NMR Properties of osmium

Common reference compound: OsO4/CCl4.

Table of NMR-active nucleus propeties of osmium
  Isotope 1 Isotope 2 Isotope 3
Isotope 187Os 189Os
Natural abundance /% 1.6 16.1
Spin (I) 1/2 3/2
Frequency relative to 1H = 100 (MHz) 2.282331 7.765400
Receptivity, DP, relative to 1H = 1.00 0.000000199 0.000393
Receptivity, DC, relative to 13C = 1.00 0.00113 2.25
Magnetogyric ratio, γ (107 rad T‑1 s-1) 0.6192895 2.10713
Magnetic moment, μ (μN) 0.1119804 0.851970
Nuclear quadrupole moment, Q/millibarn - +856(28)
Line width factor, 1056 l (m4) - 0.98


  1. R.K. Harris in Encyclopedia of Nuclear Magnetic Resonance, D.M. Granty and R.K. Harris, (eds.), vol. 5, John Wiley & Sons, Chichester, UK, 1996. I am grateful to Professor Robin Harris (University of Durham, UK) who provided much of the NMR data, which are copyright 1996 IUPAC, adapted from his contribution contained within this reference.
  2. J. Mason in Multinuclear NMR, Plenum Press, New York, USA, 1987. Where given, data for certain radioactive nuclei are from this reference.
  3. P. Pyykkö, Mol. Phys., 2008, 106, 1965-1974.
  4. P. Pyykkö, Mol. Phys., 2001, 99, 1617-1629.
  5. P. Pyykkö, Z. Naturforsch., 1992, 47a, 189. I am grateful to Professor Pekka Pyykkö (University of Helsinki, Finland) who provided the nuclear quadrupole moment data in this and the following two references.
  6. D.R. Lide, (ed.), CRC Handbook of Chemistry and Physics 1999-2000 : A Ready-Reference Book of Chemical and Physical Data (CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida, USA, 79th edition, 1998.
  7. P. Pyykkö, personal communication, 1998, 204, 2008, 2010.

WebElements chemistry shop

You can buy periodic table posters, mugs, T-shirts, periodic table fridge magnets, games, molecular models, and more at the WebElements periodic table shop