# Temperature-dependent diffusion

**URL:** <https://discourse.opengeosys.org/t/temperature-dependent-diffusion/1848>\
**Category:** Help & Support\
**Created:** [April 16, 2026, 1:04pm UTC](https://discourse.opengeosys.org/t/temperature-dependent-diffusion/1848 "2026-04-16T13:04:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rose-nelly](https://discourse.opengeosys.org/letter_avatar_proxy/v4/letter/r/c4cdca/32.png) [@rose-nelly](https://discourse.opengeosys.org/u/rose-nelly)\
**Post date:** [April 16, 2026, 1:04pm UTC](https://discourse.opengeosys.org/t/temperature-dependent-diffusion/1848/1 "2026-04-16T13:04:22Z")

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Hello everyone,

I would like to use the `ComponentTransport` process to perform HTC simulations and reproduce the work of Galsa et al. (2025), but I have encountered an issue with the diffusion coefficient.

I would like to prescribe a temperature-dependent diffusion coefficient with a quadratic dependence on temperature, that is, a form involving (T^2).

I first tried to use the `TemperatureDependentDiffusion` property type, but from what I understand, this implementation only supports a predefined temperature dependence and not a general quadratic expression.

So my question is:

Is there currently a way in OGS to define a quadratic temperature-dependent diffusion coefficient for `pore_diffusion` in `ComponentTransport`?

More specifically, is there a way, as for some other properties such as density or viscosity, to use a customized `Function` type for `pore_diffusion`?

Thank you in advance for your help.

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**Author:** ![MaxDax](https://discourse.opengeosys.org/letter_avatar_proxy/v4/letter/m/e9bcb4/32.png) [@MaxDax](https://discourse.opengeosys.org/u/MaxDax)\
**Post date:** [April 20, 2026, 2:10pm UTC](https://discourse.opengeosys.org/t/temperature-dependent-diffusion/1848/2 "2026-04-20T14:10:39Z")

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Hello rose-nelly,  
yes there is also the `Function` tag for properties. I think something like this should work.

```xml
<property>
   <name>pore_diffusion</name>
   <type>Function</type>
      <value>
         <expression>(temperature * temperature) *1e-10</expression>
      </value>
</property>

```

Hope i could help!  
Best  
Max

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<div class="post-metadata">

**Author:** ![rose-nelly](https://discourse.opengeosys.org/letter_avatar_proxy/v4/letter/r/c4cdca/32.png) [@rose-nelly](https://discourse.opengeosys.org/u/rose-nelly)\
**Post date:** [April 27, 2026, 3:08pm UTC](https://discourse.opengeosys.org/t/temperature-dependent-diffusion/1848/3 "2026-04-27T15:08:42Z")

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Hello MaxDax,

Thanks for your help. You’re right it seems that it is possible to use the `Function` type for the `pore_diffusion` property. I don’t know why i thought i saw on doxygen that it was not.