[lammps-users] [Help]Young's modulus of crystalline copper

Hi, everyone

Recently I calculated Young’s modulus of crystalline copper along [100], but the obtained value (167.3GPa) is much larger than experimental value (72.6GPa), [See Milstein F, Rasky D. Philosophhical Magzine A, 1982, 45(1):49] I wander whether I misunderstand some physical concepts or there is any problem in my script in LAMMPS.

Attachement please find the script file and input file and the output result.

PS: There is no need to debug the script file.

Thanks for your help.

Jervis Chu

Cu_u3.eam (35.6 KB)

Young-100.in (978 Bytes)

Cu-100.xrd (49.9 KB)

Cu-100.log.txt (1.77 KB)


Are you aware that other normal stress also changed? In other words, you are not applying uniaxial strain/stress on [100] direction. One way to achieve your purpose, I think, probably is using NPT to let the lateral box relax under null stress while deform the loading axis at a prescribed strain or strain rate. Hope this helps.