# How to solve the "No default Proper Dih. types?"

**URL:** <https://gromacs.bioexcel.eu/t/how-to-solve-the-no-default-proper-dih-types/3133>\
**Category:** User discussions\
**Created:** [November 12, 2021, 8:06am UTC](https://gromacs.bioexcel.eu/t/how-to-solve-the-no-default-proper-dih-types/3133 "2021-11-12T08:06:13Z")\
**Posts on this page:** 1\
**Showing post:** 22

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**Author:** ![heman\_t](https://avatars.discourse-cdn.com/v4/letter/h/13edae/32.png) [@heman\_t](https://gromacs.bioexcel.eu/u/heman_t)\
**Post date:** [December 6, 2021, 3:15pm UTC](https://gromacs.bioexcel.eu/t/how-to-solve-the-no-default-proper-dih-types/3133/22 "2021-12-06T15:15:30Z")

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@jalemkul After removing only those _quadruplets_ from the `lig.prm` which have also been defined in the `ffbonded.itp`, I could move past this hurdle.

But another anomaly creeped in during the energy minimization step. I had faced this [earlier too](https://gromacs.bioexcel.eu/t/non-converging-fmax-in-energy-minimization/3240/4) while using the Jul-2021 version of charmm36.

@Mikel led me to another similar issue. I tried reducing the em\_step size, increase the box dimensions but in vain. I’m still trying out other ways to work around this issue.

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