Dear Lammps users,

I am working on dynamics of fluids in carbon models. The carbon

model remains fixed during simulation. I am using "NVE/limit 0.05" for

the fluid molecules for equilibration and to remove any high energy

configurations. However, the temperature and energy (both KE and PE)

increase during the simulation.

I am attaching the input script . Any help will be appreciated.

Dear Lammps users,

I am working on dynamics of fluids in carbon models. The carbon

model remains fixed during simulation. I am using "NVE/limit 0.05" for

the fluid molecules for equilibration and to remove any high energy

configurations. However, the temperature and energy (both KE and PE)

increase during the simulation.

there is no reason why this should not happen. nve/limit only applies

restrictions when atoms reach the threshold. otherwise it will behave just

like fix nve.

a more effective way to remove initial high potential energy spots would be

to run a minimization first.

axel.

Dear Axel,

Many thanks for your reply. I found that the some atoms were

experiencing large forces during the simulation. So, I tried using a

soft potential. Below is shown part of my input script :

pair_style lj/cut/coul/long/soft 2.0 0.5 10.0 10.0 12.0

read_data lammps_data.dat

pair_coeff * * 0.0 0.0 0.95

pair_coeff 1 8 0.0546 3.08 0.95

pair_coeff 2 8 0.00 1.4 0.95

pair_coeff 3 8 0.0744 3.275 0.95

pair_coeff 4 8 0.00 1.4 0.95

pair_coeff 5 8 0.106 2.88 0.95

pair_coeff 6 8 0.0955 2.9 0.95

pair_coeff 7 8 0.04 2.610 0.95

pair_coeff 1 9 0.0934 3.205 0.95

pair_coeff 2 9 0.00 1.525 0.95

pair_coeff 3 9 0.127 3.4 0.95

pair_coeff 4 9 0.00 1.525 0.95

pair_coeff 5 9 0.181 3.005 0.95

pair_coeff 6 9 0.163 3.025 0.95

pair_coeff 7 9 0.0685 2.735 0.95

pair_coeff 8 8 0.053654 2.8 0.95

pair_coeff 8 9 0.0917 2.925 0.95

pair_coeff 9 9 0.1569 3.05 095

This is working fine. When I switch to full strength of the potential

from 0.95 to 1.0, I get an error

Dear Axel,

Many thanks for your reply. I found that the some atoms were

experiencing large forces during the simulation. So, I tried using a

soft potential. Below is shown part of my input script :

pair_style lj/cut/coul/long/soft 2.0 0.5 10.0 10.0 12.0

read_data lammps_data.dat

pair_coeff * * 0.0 0.0 0.95

pair_coeff 1 8 0.0546 3.08 0.95

pair_coeff 2 8 0.00 1.4 0.95

pair_coeff 3 8 0.0744 3.275 0.95

pair_coeff 4 8 0.00 1.4 0.95

pair_coeff 5 8 0.106 2.88 0.95

pair_coeff 6 8 0.0955 2.9 0.95

pair_coeff 7 8 0.04 2.610 0.95

pair_coeff 1 9 0.0934 3.205 0.95

pair_coeff 2 9 0.00 1.525 0.95

pair_coeff 3 9 0.127 3.4 0.95

pair_coeff 4 9 0.00 1.525 0.95

pair_coeff 5 9 0.181 3.005 0.95

pair_coeff 6 9 0.163 3.025 0.95

pair_coeff 7 9 0.0685 2.735 0.95

pair_coeff 8 8 0.053654 2.8 0.95

pair_coeff 8 9 0.0917 2.925 0.95

pair_coeff 9 9 0.1569 3.05 095

This is working fine. When I switch to full strength of the potential

from 0.95 to 1.0, I get an error

----------------------------------------------------------

Step c_mytemp PotEng KinEng Fmax E_vdwl E_coul E_pair E_bond E_angle

E_long E_tail

100000 302.94912 -28974.945 1914.4316 202.90136

-2193.2657 -1299.8602 -29793.114 401.92992 416.23932

-26299.988 0

100100 306.07354 -28993.423 1934.1758 193.19966

-1846.9499 -1704.2272 -29852.518 412.88093 446.21454

-26301.341 0

ERROR on proc 0: Bond atoms 6303 6305 missing on proc 0 at step 100130

(../ntopo_bond_all.cpp:63)

------------------------------------------------------------

---------------------------------------------

My question is after equilibration using (lamda = 0.95) I switch back

to full potential (lambda = 1) and got this error. I will appreciate

your help.

http://lammps.sandia.gov/doc/Section_errors.html