"Import log.lammps. Abstract the data from it to plot out the curve of Temp vs Step, PotEng vs. Temp "
"The data abstracted are in the format"
"Step" "Atoms" "Temp" "Press" "PotEng" "KinEng" "TotEng" "Volume" "Enthalpy"
SetDirectory[NotebookDirectory[]];

(*rawdata=Import["1700.lammpstrj","Table"];*)
rawdata=Import["log.lammps","Table"];
lrawdata=Length[rawdata];
(*For[i=1,i≤lrawdata,l++,*)
count=0;

For[i=1,i≤lrawdata,i++,
data=rawdata[[i]];
If[Length[data]==9,
If[
Table[NumberQ[data[[j]]],{j,1,9}]==Table[True,{i,1,9}],
count=count+1;
data9[count]=data;
];(*end if*)
];(*end if *)
];(*end for *)

PotEng[i_]:=data9[i][[5]];
Temp[i_]:=data9[i][[3]];
Step[i_]:=data9[i][[1]];
tStepTemp=Table[{Step[i],Temp[i]},{i,1,count}];
ListPlot[tStepTemp,PlotLabel->"Temp vs Step"]

tStepPotEng=Table[{Step[i],PotEng[i]},{i,1,count}];
ListPlot[tStepPotEng,PlotLabel->"PotEng vs Step"]


tTempPotEng=Table[{Temp[i],PotEng[i]},{i,1,count}];
ListPlot[tTempPotEng,PlotLabel->"PotEng vs Temp"]