Let me share what I have found so far. I hope someone can at least verify if the following is correct:
1. in plot_1d routine of chdens.f90, the plotted x-axis is deltax*dble(i-1). 2. deltax = m1 / (nx - 1) 3. and m1 = sqrt (e1 (1)**2 + e1 (2)**2 + e1 (3)**2) So in my case, m1, which is the modulus of e1=0.333 in alat units. That’s why the x-axis runs from 0 to ~0.33. However, the origin of the plot is (0,0,0) and not x0. Thank you, Vahid On Jun 20, 2017, at 4:12 PM, Vahid Askarpour <[email protected]<mailto:[email protected]>> wrote: Just a correction to my pp.x input file: I actually used cartesian coordinates for the e1 and x0. So 0.3571863 0.2721583 0.1838386 for x0 and 0.1171583 0.2721583 0.1535005 for e1. Vahid Feedback<http://aka.ms/SafetyTipsFeedback> Dear QE Users, In order to calculate the total potential along one of the SnSe bonds (Se2-Sn4), I first performed a self-consistent run with the following lattice parameters. ibrav=8, celldm(1)=21.34350847, celldm(2)=0.3628777, celldm(3)=0.38586894 Sn 0.882841736 0.250000000 0.602195343 Sn 0.617158264 0.750000000 0.102195343 Sn 0.382841736 0.250000000 0.897804657 Sn 0.117158264 0.750000000 0.397804657 Se 0.142813748 0.250000000 0.976427467 Se 0.357186252 0.750000000 0.476427467 Se 0.642813748 0.250000000 0.523572533 Se 0.857186252 0.750000000 0.023572533 I then ran pp.x with the following input: &inputpp prefix = 'SnSe' filplot = 'potential.dat' plot_num= 1 / &plot iflag=1 output_format=0 nfile = 1 filepp(1) = 'potential.dat' e1(1)=0.117158264, e1(2)=0.750000000, e1(3)= 0.397804657, x0(1)=0.357186252, x0(2)= 0.750000000, x0(3)=0.476427467, nx=100, fileout= 'VSe2_Sn4.dat’ / The bond length is 2.73A=5.16Bohr. Attached is the output of potential vs. distance. The x-axis runs from 0 to ~0.33. According to other links in the Forum, the x-axis is in atomic units. Two possibilities: 1. The distance is in Bohr. So is the pp.x code plotting from 0 to 0.33 Bohr even though the bond length is 5.16Bohr as defined by the vectors x0 and e1? 2. The distance is in alat. Then 0.33*alat=7.04Bohr. This is longer than the bond length. So what is the unit of the x-axis? Thank you, Vahid Vahid Askarpour Department of Physics and Atmospheric Science Dalhousie University, Halifax, NS, Canada <SnSe_potential.pdf>_______________________________________________ Pw_forum mailing list [email protected]<mailto:[email protected]> http://pwscf.org/mailman/listinfo/pw_forum
_______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
