Tutorial

This tutorial is done by using the input file in sample/Standard/Spin/HeisenbergSquare/ (mVMC) or sample/CG/Heisenberg/ (HPhi).

Run HPhi/vmc.out

  • For {\mathcal H}\Phi

    Calculate the ground state and the correlation function at that state.

    $ ../../../../src/HPhi -s stan.in
    
  • For mVMC

    Optimize the trial wavefunction.

    $ ../../../../src/vmc.out -s StdFace.def
    

    Add the following line in StdFace.def to compute the correlation function.

    NVMCCalMode = 1
    

    Compute the correlation function.

    $ ../../../../src/vmc.out -s StdFace.def output/zqp_opt.dat
    

Then the one- and two-body correlation function are written to files in the output/ directory.

Related files

Fourier transformation of correlation functions

Perform the Fourier transformation of the correlation function by using the utility fourier.

$ ../../../../tool/fourier namelist.def geometry.dat

Then the Fourier-transformed correlation functions are written to a file in output/.

Related files

Display correlation functions

Plot the correlation function in the k space by using the utility corplot.

$ ../../../../tool/corplot output/zvo_corr.dat
or
$ ../../../../tool/corplot output/zvo_corr_eigen0.dat

Then the following message appears in the terminal.

#####  Plot Start  #####

   Please specify target number from below (0 or Ctrl-C to exit):

   Real Part Without ErrorBar
     [ 1] Up-Up [ 2] Down-Down [ 3] Density-Density [ 4] SzSz [ 5] S+S- [ 6] S-S+
   Imaginary Part Without ErrorBar
     [11] Up-Up [12] Down-Down [13] Density-Density [14] SzSz [15] S+S- [16] S-S+
   Real Part With ErrorBar
     [21] Up-Up [22] Down-Down [23] Density-Density [24] SzSz [25] S+S- [26] S-S+
   Imaginary Part With ErrorBar
     [31] Up-Up [32] Down-Down [33] Density-Density [34] SzSz [35] S+S- [36] S-S+

   Target :

Type a number corresponding to the quantity to be plotted (for example 4) and press Enter, then gnuplot is launched and the 3D figure is displayed (Fig. 1).

_images/corplot.png

The 3D picture when Target : 4. The solid black lines indicate the Brillouin zone.

Related files