Dear LAMMPS users,
I am working on the viscosity calculation in which I have a problem of integrating tensor components and writing output after “fix ave/correlate/long”. However, I do not have any problem while using “fix ave/correlate” command. I am using “lammps-30Jul16” version. Here below my input script,
The below once works fine,
fix TEN all ave/correlate 5 400 2000 v_pxy v_pxz type auto file correlation1.dat ave running
variable vxy equal trap(f_TEN[3])
variable vxz equal trap(f_TEN[4])
thermo_style custom step temp press v_vxy v_vxz
thermo 2000
In the case of “fix ave/correlate/long”, the manual explains this fix is similar to “fix ave/correlate” one. Therefore,
fix TEN all ave/correlate/long 5 2000 v_pxy v_pxz type auto file correlation2.dat
variable vxy equal trap(f_TEN[1])
variable vxz equal trap(f_TEN[2])
thermo_style custom step temp press v_vxy v_vxz
thermo 2000
My problem is, when I use “thermo_style multi” command I do not receive any problem, however when I switch to “thermo_style custom” like the above one, I get “ERROR: Mismatched fix in variable formula” error. I would like to integrate and write viscosity components at every Nfreq steps (2000, in this case). It would be great if someone helps me out from this issue.
Common errors in the manual say for this particular Error:
Mismatched fix in variable formula: A fix is referenced incorrectly or a fix that produces per-atom values is used in an equal-style variable formula.
I wonder if the above two fixes almost similar, it should work. Am I missing something here?
Thanks in advance
Regards,
Veerapandian