Dear Espresso users-<br><br>I am currently using the software calculating interatomic force constants. I started with a armchair edge graphene nanoribbon of 3^0.5*bondlength width which means two primitive unit cells of graphene are aligned along the axial direction of ribbon and separated by (3^0.5)*bondlength. However, I found the software failed to give some of the force constant. Attached is the structure I am trying to study and below is the script I used for force constants calcualtion.<br>
<br>SCF calcualtion<br>**************************************************************************************************<br>&control<br> calculation='scf'<br> restart_mode='from_scratch',<br> tstress = .true.<br>
tprnfor = .true.<br> prefix='GNR',<br> pseudo_dir = '/scratch/scratch96/h/huang87/espresso-4.1.1/pseudo/',<br> outdir='/scratch/scratch96/h/huang87/espresso-4.1.1/ZhenCalculation/GNRTry2/'<br>
/<br> &system<br> ibrav= 0, celldm(1) =8.04, nat= 8, ntyp= 1, nbnd= 20,<br> ecutwfc =16.0, occupations='smearing', smearing='marzari-vanderbilt',<br> degauss=0.05<br><br> /<br> &electrons<br>
diagonalization='cg'<br> conv_thr = 1.0d-8<br> mixing_beta = 0.7<br> /<br>ATOMIC_SPECIES<br> C 12.0107 C.pz-rrkjus.UPF<br><br>CELL_PARAMETERS<br><br>7.50746269 0.00000000 0.00000000<br>0.00000000 2.00000000 0.00000000<br>
0.00000000 0.00000000 1.00000000<br><br><br>ATOMIC_POSITIONS<br><br> C 0.462 0.5 0.000<br> C 0.538 0.5 0.000<br> C 0.462 0.5 0.333<br> C 0.538 0.5 0.333<br> C 0.500 0.5 0.500<br> C 0.577 0.5 0.500<br> C 0.500 0.5 0.833<br>
C 0.577 0.5 0.833<br><br>K_POINTS (automatic)<br> 1 1 32 0 0 0<br>*****************************************************************************<br><br>Phonon calculation <br><br>phonons of Ti<br> &inputph<br> tr2_ph=1.0d-12,<br>
prefix='GNR',<br> ldisp=.true.,<br> nq1=1, nq2=1, nq3=16<br> amass(1)=12.0107,<br> outdir='/scratch/scratch96/h/huang87/espresso-4.1.1/ZhenCalculation/GNRTry2/',<br> fildyn='GNR.dyn',<br> /<br>
*************************************************************************<br>
<br><br>force constants from GNR.dyn1<br>***************************************************************************<br> 1 1<br>252.12788999 0.00000000 -0.00114015 0.00000000 -14.77300805 0.00000000<br> -0.00114015 0.00000000 ************ 0.00000000 -0.06520954 0.00000000<br>
-14.77300805 0.00000000 -0.06520954 0.00000000 -93.03374039 0.00000000<br> 1 2<br>************ 0.00000000 0.09747458 0.00000000 -1.20698824 0.00000000<br> -0.01665358 0.00000000 113.56482271 0.00000000 -0.00847488 0.00000000<br>
5.45990614 0.00000000 -0.00244794 0.00000000 113.74430800 0.00000000<br> 1 3<br> 0.53138677 0.00000000 0.01284739 0.00000000 -0.00496088 0.00000000<br> 0.00078527 0.00000000 1.10083154 0.00000000 -0.00960997 0.00000000<br>
-0.01328205 0.00000000 -0.13249470 0.00000000 -0.93853159 0.00000000<br> 1 4<br> -0.36705054 0.00000000 0.00166782 0.00000000 0.03803961 0.00000000<br> -0.01073043 0.00000000 -0.02005837 0.00000000 0.03032361 0.00000000<br>
-0.33345226 0.00000000 0.12638729 0.00000000 -1.53647444 0.00000000<br> 1 5<br> -0.36239819 0.00000000 -0.02331924 0.00000000 -0.58155909 0.00000000<br> -0.03210181 0.00000000 -0.86035688 0.00000000 -0.08297313 0.00000000<br>
1.52018776 0.00000000 0.05112061 0.00000000 0.32584098 0.00000000<br><br>***********************************************************************<br>Best Regards<br>-------<br>Zhen (Alex) Huang<br>Ph.D. Student<br>
Nanoscale Transport Research Group<br>Laboratory for Computational Methods in Emerging Technologies<br>Cooling Technologies Research Center<br>School of Mechanical Engineering<br>
Purdue University<br>Tel: 765 722 1113<br>