class GSData:


    def __init__(self, sysname, directory=os.cwd):

        file_k     = os.path.join(directory, "%s_k.data" % sysname)
        file_eigen = os.path.join(directory, "%s_eigen.data" % sysname)

        data_k     = np.loadtxt(file_k, usecols=[1, 2, 3, 4], dtype=float)
        data_eigen = np.loadtxt(file_eigen, usecols=[2, 3], dtype=float)

        homo = np.amax(data_eigen[data_eigen[:, 1] > 1, 0])
        lumo = np.amin(data_eigen[data_eigen[:, 1] < 1, 0])

        self.dierctory = directory
        self.sysname   = sysname
        self.k         = data_k
        self.eigen     = data_eigen.reshape([len(data_k), -1, 2])
        self.homo      = homo
        self.lumo      = lumo
        self.fermi     = (homo + lumo) * 0.5



    def __repr__(self):
        return '<SALMON Eigen {SYSNAME} on {DIRECTORY}>'.format(
            SYSNAME = self.sysname, DIRECTORY = seld.directory,
        )

    def calc_dos()

class RTData:


class PData: