# Isotope Support

**URL:** <https://discuss.avogadro.cc/t/isotope-support/7211>\
**Category:** Development\
**Created:** [November 3, 2025, 4:14pm UTC](https://discuss.avogadro.cc/t/isotope-support/7211 "2025-11-03T16:14:26Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![ghutchis](https://discuss.avogadro.cc/user_avatar/discuss.avogadro.cc/ghutchis/32/456_2.png) [@ghutchis](https://discuss.avogadro.cc/u/ghutchis)\
**Post date:** [November 3, 2025, 8:59pm UTC](https://discuss.avogadro.cc/t/isotope-support/7211/3 "2025-11-03T20:59:47Z")

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I’ll mention that I _absolutely_ could use some help digging up syntax for isotopes for input generators.

- CP2K
- Dalton
- GAMESS
- GAMESS-UK
- Gaussian (e.g., add `C(Iso=13)` to the atom symbol
- ORCA (e.g., add `M <mass>` to the end of the XYZ line
- Molpro
- NWChem
- Psi
- PySCF
- Q-Chem
- Terachem

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