# About the usage of gmx hbond

**URL:** <https://gromacs.bioexcel.eu/t/about-the-usage-of-gmx-hbond/3722>\
**Category:** User discussions\
**Created:** [February 22, 2022, 7:21am UTC](https://gromacs.bioexcel.eu/t/about-the-usage-of-gmx-hbond/3722 "2022-02-22T07:21:53Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Yao](https://avatars.discourse-cdn.com/v4/letter/y/2bfe46/32.png) [@Yao](https://gromacs.bioexcel.eu/u/Yao)\
**Post date:** [February 22, 2022, 7:21am UTC](https://gromacs.bioexcel.eu/t/about-the-usage-of-gmx-hbond/3722/1 "2022-02-22T07:21:53Z")

</div>

GROMACS version:2018.8  
GROMACS modification: No  
Here post your question  
I want to use the **gmx hbond** command to analyze the hydrogen bond of a box by region in the Z direction. For example, the box size is 5nm × 5nm × 5nm, and I want to divide it into three regions z=0~ 1.5nm, 1.5~3.5nm, and 3.5~5.0nm in the Z direction. How do I calculate the hydrogen bond for each of these three regions by gmx hbond? How do I select the specified z-axis range in gmx hbond?