[QE-users] Why does num=7 have positive and negative values?

[toshi1higu at docomo.ne.jp]

Dear QE Users and developers,
My name is Toshiharu Higuchi.
My question is why the values calculated with num=7 have positive and
negative values.
When calculating with num=7, |psi|^2 is output, and I thought only positive
values would be output.
However, in reality, both positive and negative values are output.
Why is this?
Can someone explain?
Below are the pw.in and pp.in files.
Pseudopotential is set to ultrasoft.
Also, spin_component is set to default.

Best regard
Toshiharu Higuchi

【pw.in file】
&CONTROL
                       title = 'Open-ended_6,0_HCNT230328' ,
                 calculation = 'scf' ,
                restart_mode = 'restart' ,
                  wf_collect = .true. ,
                      outdir = '/home/user/tmp/' ,
                  pseudo_dir = '/home/user/user/espresso-5.0.1/espresso-5.0.
1/pseudo/' ,
                      prefix = 'Open-ended_6,0_HCNT230328' ,
                   verbosity = 'high' ,
                     tstress = .false. ,
                     tprnfor = .false. ,
                     tefield = .true. ,
                    dipfield = .true. ,
                    lelfield = .false. ,  
/  
&SYSTEM
                       ibrav = 8,
                           A = 20.0 ,
                           B = 20.0 ,
                           C = 45.0 ,
                         nat = 84,
                        ntyp = 2,
                     ecutwfc = 26 ,
                     ecutrho = 156 ,
                        nbnd = 228,
                 occupations = 'smearing' ,
         starting_spin_angle = .true. ,
                     degauss = 0.003675 ,
                    smearing = 'gaussian' ,
                       nspin = 1 ,
            exxdiv_treatment = 'gygi-baldereschi' ,
                        edir = 3 ,
                     emaxpos = 0.9 ,
                      eopreg = 0.2 ,
                        eamp = 0.014585 ,
                         nr1 = 36 ,
 /
 &ELECTRONS
            electron_maxstep = 2000,
                    conv_thr = 1.D-6 ,
                 mixing_mode = 'plain' ,
                 mixing_beta = 0.05 ,
 /
ATOMIC_SPECIES
    C   12.00000  C.pz-rrkjus.UPF 
    H    1.00000  H.pz-rrkjus.UPF 
ATOMIC_POSITIONS angstrom 
    H     12.327940199   10.000000588   15.766377794    
    C     12.062957809   11.190766202   17.548631524    
    C     12.366482536   10.000000902   16.862324222    
    C     12.069397875   11.194555299   18.968440470    
    C     12.380403483    9.999999193   19.672583038    
    C     12.060876291   11.189804950   21.791812843    
    C     12.382678930    9.999999644   21.083391695    
    C     12.063244987   11.191169496   23.201214747    
    C     12.378768341   10.000000084   23.909870604    
    C     12.058247238   11.188225674   26.028356853  
  
   　Omission
    
    C     11.189303551    7.940162598   23.909988694    
    C     12.058247608    8.811774216   26.028357186    
    C     11.189633408    7.939616789   25.322607139    
    C     12.057081279    8.812519033   27.451447780    
    C     11.170128386    7.973580914   28.148003486    
    H     11.183822814    7.950091720   29.245519176    
K_POINTS gamma 

【pp.in file】
&INPUTPP
                      prefix = 'Open-ended_6,0_HCNT230328' ,
                      outdir = '/home/user/tmp' ,
                     filplot = 'num7_HCNT230328_2' ,
                    plot_num = 7,
                   kpoint(1) = 1,
                   kpoint(2) = 1,
                    kband(1) = 141,
                    kband(2) = 151,
                       lsign = .true. ,
 /
 &PLOT
                       nfile = 1 ,
                   weight(1) = 1.0,
                     fileout = '.xsf' ,
                       iflag = 3 ,
               output_format = 5 ,
 /