# Determinant of Jacobian (-154.37) for cell 7215 is smaller than minimum permissible value (1e-06)!

**URL:** <https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788>\
**Category:** PyLith\
**Created:** [April 9, 2021, 10:40pm UTC](https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788 "2021-04-09T22:40:51Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![LauraBM](https://avatars.discourse-cdn.com/v4/letter/l/3bc359/32.png) [@LauraBM](https://community.geodynamics.org/u/LauraBM)\
**Post date:** [April 9, 2021, 10:40pm UTC](https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788/1 "2021-04-09T22:40:51Z")

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Hello,

I get this error with a negative determinant for a hexahedral cell that is oriented according the Pylith manual. This cell does not look highly distorted at all. What surprises me is the negative value. Could you please explain what could cause this error?

Thank you,

Laura

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**Author:** ![baagaard](https://yyz2.discourse-cdn.com/flex036/user_avatar/community.geodynamics.org/baagaard/32/615_2.png) [@baagaard](https://community.geodynamics.org/u/baagaard)\
**Post date:** [April 10, 2021, 1:41am UTC](https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788/2 "2021-04-10T01:41:10Z")

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The only explanations I know of for a Jacobian of -154.37 (negative and a magnitude much larger than one) is that the orientation is incorrect or the coordinates of the vertices are incorrect.

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**Author:** ![peiyu](https://avatars.discourse-cdn.com/v4/letter/p/94ad74/32.png) [@peiyu](https://community.geodynamics.org/u/peiyu)\
**Post date:** [September 22, 2022, 4:13pm UTC](https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788/3 "2022-09-22T16:13:22Z")

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Dear baagaard,  
I got the same probelm, and would you like to tell me how to solve it?  
Thank you,  
Peiyu

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**Author:** ![baagaard](https://yyz2.discourse-cdn.com/flex036/user_avatar/community.geodynamics.org/baagaard/32/615_2.png) [@baagaard](https://community.geodynamics.org/u/baagaard)\
**Post date:** [September 22, 2022, 4:31pm UTC](https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788/4 "2022-09-22T16:31:53Z")

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Please provide more information, including

- Which version of PyLith are you using?
- What software are you using to create the mesh?
- What type of mesh is it (triangular, quadrilateral, tetrahedral, or hexahedral cells)?
- Have you checked the mesh quality?
- What is the value of the Jacobian that is triggering the error?

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**Author:** ![peiyu](https://avatars.discourse-cdn.com/v4/letter/p/94ad74/32.png) [@peiyu](https://community.geodynamics.org/u/peiyu)\
**Post date:** [September 23, 2022, 2:41am UTC](https://community.geodynamics.org/t/determinant-of-jacobian-154-37-for-cell-7215-is-smaller-than-minimum-permissible-value-1e-06/1788/5 "2022-09-23T02:41:57Z")

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Dear baagaard,  
Thanks for your reminding. I checked that there was a problem with the grid.