# Problem in Grompp with Verlet

**URL:** <https://gromacs.bioexcel.eu/t/problem-in-grompp-with-verlet/147>\
**Category:** User discussions\
**Created:** [May 15, 2020, 10:10pm UTC](https://gromacs.bioexcel.eu/t/problem-in-grompp-with-verlet/147 "2020-05-15T22:10:54Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![PonchoArvayo](https://avatars.discourse-cdn.com/v4/letter/p/6bbea6/32.png) [@PonchoArvayo](https://gromacs.bioexcel.eu/u/PonchoArvayo)\
**Post date:** [May 15, 2020, 10:10pm UTC](https://gromacs.bioexcel.eu/t/problem-in-grompp-with-verlet/147/1 "2020-05-15T22:10:54Z")

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GROMACS version: 5.0.2  
GROMACS modification: No  
Here post your question Hello Dear Gromacs users: I want to run an equilibration using grompp, but i have the following error: With Verlet lists coulomb!=rvdw is not supported (except for coulomb\>rvdw with PME electrostatics). Could you help me please? My mdp is the following:

integrator = md

dt = 0.02

nsteps = 500000

nstxout = 0

nstvout = 0

nstfout = 0

nstlog = 1000

nstxout-compressed = 1000

compressed-x-precision = 100

cutoff-scheme = Verlet

nstlist = 20

ns\_type = grid

pbc = xyz

verlet-buffer-tolerance = 0.005

coulombtype = reaction-field

crcoulomb = 1.1

epsilon\_r = 15 ; 2.5 (with polarizable water)

epsilon\_rf = 0

vdw\_type = cutoff

vdw-modifier = Potential-shift-verlet

rvdw = 1.1

tcoupl = v-rescale

tc-grps = System

tau\_t = 1.0

ref\_t = 310

gen-vel = yes

gen-temp = 310

Pcoupl = berendsen

Pcoupltype = semiisotropic

tau-p = 4.0

compressibility = 4.5e-5 4.5e-5

ref-p = 1.0 1.0

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<div class="post-metadata">

**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\
**Post date:** [May 17, 2020, 11:01am UTC](https://gromacs.bioexcel.eu/t/problem-in-grompp-with-verlet/147/2 "2020-05-17T11:01:01Z")

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> [@PonchoArvayo](#):
>
> crcoulomb = 1.1

`crcoulomb` is not a valid keyword, so `grompp` falls back to the default value of 1.0 for `rcoulomb`, triggering the warning because `rvdw` is set to 1.1.