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# The limits of the nuclear landscape

## Abstract

In 2011, 100 new nuclides were discovered1. They joined the approximately 3,000 stable and radioactive nuclides that either occur naturally on Earth or are synthesized in the laboratory2,3. Every atomic nucleus, characterized by a specific number of protons and neutrons, occupies a spot on the chart of nuclides, which is bounded by ‘drip lines’ indicating the values of neutron and proton number at which nuclear binding ends. The placement of the neutron drip line for the heavier elements is based on theoretical predictions using extreme extrapolations, and so is uncertain. However, it is not known how uncertain it is or how many protons and neutrons can be bound in a nucleus. Here we estimate these limits of the nuclear ‘landscape’ and provide statistical and systematic uncertainties for our predictions. We use nuclear density functional theory, several Skyrme interactions and high-performance computing, and find that the number of bound nuclides with between 2 and 120 protons is around 7,000. We find that extrapolations for drip-line positions and selected nuclear properties, including neutron separation energies relevant to astrophysical processes, are very consistent between the models used.

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## Acknowledgements

This work was supported by the Office of Nuclear Physics, US Department of Energy, and by the Academy of Finland.

## Author information

Authors

### Contributions

Theoretical calculations were performed by J.E., M.K. and M.S. The data were analysed by N.B., J.E., W.N., E.O. and A.M.P. The manuscript was prepared by J.E. and W.N. All authors contributed to this work, discussed the results and conclusions, and commented on the manuscript.

### Corresponding author

Correspondence to Witold Nazarewicz.

## Ethics declarations

### Competing interests

The authors declare no competing financial interests.

## Supplementary information

### Supplementary Information

This file contains Supplementary Text and Data, Supplementary Figures 1-5, Supplementary Table 1 and additional references. (PDF 8566 kb)

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Erler, J., Birge, N., Kortelainen, M. et al. The limits of the nuclear landscape. Nature 486, 509–512 (2012). https://doi.org/10.1038/nature11188

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• DOI: https://doi.org/10.1038/nature11188

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