def getV(self):
        if not exists('groupv'):
            mkdir('groupv')
        cd('groupv')
        cp('../FORCE_CONSTANTS', '.')
        cp('../POSCAR', '.')
        cp('../disp.yaml', '.')
        self.generate_vconf()
        passthru(config.phonopy + "--tolerance=1e-4    v.conf")
        self.drawV()
        cd('..')