computed temperature for fix temp/berendsen cannot be 0.0..

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1

Dear Lammps users,

I am running simulation of CO2 with ReaxFF. I am using ReaxFF parameters for hydrocarbon of Chenoweth. I tried to set the volume of gas-phase CO2 and ran with nve, however, the simulation couldn’t run because of the error “Computed temperature for fix temp/berendsen cannot be 0.0…”. I referred to one email posted on Mailing list from 2012 "correct volume for supercritical CO2 system" and tried to run simulation of CO2 following those advices, however, I got the similar problem.

I attached my input and and data files. Could you please give me any advice to help me address this problem.

Kind regards,

TranLe

data.CO2 (11.8 KB)

in.CO2 (872 Bytes)

2

Dear Lammps users,

I am running simulation of CO2 with ReaxFF. I am using ReaxFF parameters
for hydrocarbon of Chenoweth. I tried to set the volume of gas-phase CO2
and ran with nve, however, the simulation couldn't run because of the error
"Computed temperature for fix temp/berendsen cannot be 0.0...". I referred
to one email posted on Mailing list from 2012 "*correct volume for
supercritical CO2 system
<https://sourceforge.net/p/lammps/mailman/message/29953338/>" *and tried
to run simulation of CO2 following those advices, however, I got the
similar problem.

​*what* similar problem? what do you mean by "i tried to set the volume of
gas phase CO2"?

well, how to deal with the fix temp/berendsen error message should be
self-evident to anybody that has read the documentation and understood how
it works. if your kinetic energy is zero, you can multiply it by any factor
you choose, and you'll still get zero. so it cannot work for systems, that
do not have an initial temperature asses, i.e. have a temperature of 0K.

I attached my input and and data files. Could you please give me any
advice to help me address this problem.

​i don't see a problem here. your input does what you ask it to do.​ if
this is not what you want, you have to change the input accordingly. but
since you didn't say what you problem is, it will be impossible to give
advice.

​axel.​

3

Dear Dr Axel,

Thank for your reply.

According to advices I read from Mailing list, I set the volume and ran simulation with nvt and then I received the error “segmentation fault”. The kinetic energy is nonzero, however, potential energy is nan. The problem is that my simulation couldn’t run although I did it with different conditions. Could you please tell me what’s gone wrong with my system?

Kind regards

Trance

4

Dear Dr Axel,

Thank for your reply.

According to advices I read from Mailing list, I set the volume and ran
simulation with nvt and then I received the error "segmentation fault". The
kinetic energy is nonzero, however, potential energy is nan. The problem is
that my simulation couldn't run although I did it with different
conditions. Could you please tell me what's gone wrong with my system?

​i don't know. it was running on my machine without this.​ have you tried
using the very latest version of LAMMPS (11 May 2016 as of today)?

​axel.​

5

Dear Dr Axel,

Thank for your suggestion. I am using Lammps on Cori. I haven’t used the latest version of Lammps yet.

Kind regards

Tranle