Ejemplo n.º 1
0
def main(options):
    """
    Main routine to compute inelastic transport characteristics (dI/dV, d2I/dV2, IETS etc)

    Parameters
    ----------
    options : an ``options`` instance
    """
    CF.CreatePipeOutput(options.DestDir + '/' + options.Logfile)
    VC.OptionsCheck(options, 'Inelastica')
    CF.PrintMainHeader('Inelastica', options)

    options.XV = '%s/%s.XV' % (options.head, options.systemlabel)
    options.geom = MG.Geom(options.XV, BufferAtoms=options.buffer)
    # Voltage fraction over left-center interface
    VfracL = options.VfracL  # default is 0.5
    print 'Inelastica: Voltage fraction over left-center interface: VfracL =', VfracL
    # Set up electrodes and device Greens function
    elecL = NEGF.ElectrodeSelfEnergy(options.fnL, options.NA1L, options.NA2L,
                                     options.voltage * VfracL)
    elecL.scaling = options.scaleSigL
    elecL.semiinf = options.semiinfL
    elecR = NEGF.ElectrodeSelfEnergy(options.fnR, options.NA1R, options.NA2R,
                                     options.voltage * (VfracL - 1.))
    elecR.scaling = options.scaleSigR
    elecR.semiinf = options.semiinfR
    # Read phonons
    NCfile = NC4.Dataset(options.PhononNetCDF, 'r')
    print 'Inelastica: Reading ', options.PhononNetCDF
    hw = NCfile.variables['hw'][:]
    # Work with GFs etc for positive (V>0: \mu_L>\mu_R) and negative (V<0: \mu_L<\mu_R) bias voltages
    GFp = NEGF.GF(options.TSHS,
                  elecL,
                  elecR,
                  Bulk=options.UseBulk,
                  DeviceAtoms=options.DeviceAtoms,
                  BufferAtoms=options.buffer)
    # Prepare lists for various trace factors
    #GF.dGnout = []
    #GF.dGnin = []
    GFp.P1T = N.zeros(len(hw), N.float)  # M.A.M.A (total e-h damping)
    GFp.P2T = N.zeros(len(hw), N.float)  # M.AL.M.AR (emission)
    GFp.ehDampL = N.zeros(len(hw), N.float)  # M.AL.M.AL (L e-h damping)
    GFp.ehDampR = N.zeros(len(hw), N.float)  # M.AR.M.AR (R e-h damping)
    GFp.nHT = N.zeros(len(hw), N.float)  # non-Hilbert/Isym factor
    GFp.HT = N.zeros(len(hw), N.float)  # Hilbert/Iasym factor
    GFp.dIel = N.zeros(len(hw), N.float)
    GFp.dIinel = N.zeros(len(hw), N.float)
    GFp.dSel = N.zeros(len(hw), N.float)
    GFp.dSinel = N.zeros(len(hw), N.float)
    #
    GFm = NEGF.GF(options.TSHS,
                  elecL,
                  elecR,
                  Bulk=options.UseBulk,
                  DeviceAtoms=options.DeviceAtoms,
                  BufferAtoms=options.buffer)
    GFm.P1T = N.zeros(len(hw), N.float)  # M.A.M.A (total e-h damping)
    GFm.P2T = N.zeros(len(hw), N.float)  # M.AL.M.AR (emission)
    GFm.ehDampL = N.zeros(len(hw), N.float)  # M.AL.M.AL (L e-h damping)
    GFm.ehDampR = N.zeros(len(hw), N.float)  # M.AR.M.AR (R e-h damping)
    GFm.nHT = N.zeros(len(hw), N.float)  # non-Hilbert/Isym factor
    GFm.HT = N.zeros(len(hw), N.float)  # Hilbert/Iasym factor
    GFm.dIel = N.zeros(len(hw), N.float)
    GFm.dIinel = N.zeros(len(hw), N.float)
    GFm.dSel = N.zeros(len(hw), N.float)
    GFm.dSinel = N.zeros(len(hw), N.float)
    # Calculate transmission at Fermi level
    GFp.calcGF(options.energy + options.eta * 1.0j,
               options.kpoint[0:2],
               ispin=options.iSpin,
               etaLead=options.etaLead,
               useSigNCfiles=options.signc,
               SpectralCutoff=options.SpectralCutoff)
    L = options.bufferL
    # Pad lasto with zeroes to enable basis generation...
    lasto = N.zeros((GFp.HS.nua + L + 1, ), N.int)
    lasto[L:] = GFp.HS.lasto
    basis = SIO.BuildBasis(options.fn, options.DeviceAtoms[0] + L,
                           options.DeviceAtoms[1] + L, lasto)
    basis.ii -= L
    TeF = MM.trace(GFp.TT).real
    GFp.TeF = TeF
    GFm.TeF = TeF
    # Check consistency of PHrun vs TSrun inputs
    IntegrityCheck(options, GFp, basis, NCfile)
    # Calculate trace factors one mode at a time
    print 'Inelastica: LOEscale =', options.LOEscale
    if options.LOEscale == 0.0:
        # LOEscale=0.0 => Original LOE-WBA method, PRB 72, 201101(R) (2005) [cond-mat/0505473].
        GFp.calcGF(options.energy + options.eta * 1.0j,
                   options.kpoint[0:2],
                   ispin=options.iSpin,
                   etaLead=options.etaLead,
                   useSigNCfiles=options.signc,
                   SpectralCutoff=options.SpectralCutoff)
        GFm.calcGF(options.energy + options.eta * 1.0j,
                   options.kpoint[0:2],
                   ispin=options.iSpin,
                   etaLead=options.etaLead,
                   useSigNCfiles=options.signc,
                   SpectralCutoff=options.SpectralCutoff)
        for ihw in (hw > options.modeCutoff).nonzero()[0]:
            calcTraces(options, GFp, GFm, basis, NCfile, ihw)
            calcTraces(options, GFm, GFp, basis, NCfile, ihw)
        writeFGRrates(options, GFp, hw, NCfile)
    else:
        # LOEscale=1.0 => Generalized LOE, PRB 89, 081405(R) (2014) [arXiv:1312.7625]
        for ihw in (hw > options.modeCutoff).nonzero()[0]:
            GFp.calcGF(options.energy + hw[ihw] * options.LOEscale * VfracL +
                       options.eta * 1.0j,
                       options.kpoint[0:2],
                       ispin=options.iSpin,
                       etaLead=options.etaLead,
                       useSigNCfiles=options.signc,
                       SpectralCutoff=options.SpectralCutoff)
            GFm.calcGF(options.energy + hw[ihw] * options.LOEscale *
                       (VfracL - 1.) + options.eta * 1.0j,
                       options.kpoint[0:2],
                       ispin=options.iSpin,
                       etaLead=options.etaLead,
                       useSigNCfiles=options.signc,
                       SpectralCutoff=options.SpectralCutoff)
            calcTraces(options, GFp, GFm, basis, NCfile, ihw)
            if VfracL != 0.5:
                GFp.calcGF(options.energy - hw[ihw] * options.LOEscale *
                           (VfracL - 1.) + options.eta * 1.0j,
                           options.kpoint[0:2],
                           ispin=options.iSpin,
                           etaLead=options.etaLead,
                           useSigNCfiles=options.signc,
                           SpectralCutoff=options.SpectralCutoff)
                GFm.calcGF(options.energy -
                           hw[ihw] * options.LOEscale * VfracL +
                           options.eta * 1.0j,
                           options.kpoint[0:2],
                           ispin=options.iSpin,
                           etaLead=options.etaLead,
                           useSigNCfiles=options.signc,
                           SpectralCutoff=options.SpectralCutoff)
            calcTraces(options, GFm, GFp, basis, NCfile, ihw)

    # Multiply traces with voltage-dependent functions
    data = calcIETS(options, GFp, GFm, basis, hw)
    NCfile.close()
    NEGF.SavedSig.close()
    CF.PrintMainFooter('Inelastica')
    return data
Ejemplo n.º 2
0
def main(options):
    """
    Main routine to compute elastic transmission probabilities etc.

    Parameters
    ----------
    options : an ``options`` instance
    """
    CF.CreatePipeOutput(options.DestDir + '/' + options.Logfile)
    VC.OptionsCheck(options, 'pyTBT')
    CF.PrintMainHeader('pyTBT', options)

    # K-points
    if options.Gk1 > 1:
        Nk1, t1 = options.Gk1, 'GK'
    else:
        Nk1, t1 = options.Nk1, 'LIN'
    if options.Gk2 > 1:
        Nk2, t2 = options.Gk2, 'GK'
    else:
        Nk2, t2 = options.Nk2, 'LIN'
    # Generate full k-mesh:
    mesh = Kmesh.kmesh(Nk1,
                       Nk2,
                       Nk3=1,
                       meshtype=[t1, t2, 'LIN'],
                       invsymmetry=not options.skipsymmetry)
    mesh.mesh2file(
        '%s/%s.%ix%i.mesh' %
        (options.DestDir, options.systemlabel, mesh.Nk[0], mesh.Nk[1]))
    # Setup self-energies and device GF
    elecL = NEGF.ElectrodeSelfEnergy(options.fnL, options.NA1L, options.NA2L,
                                     options.voltage / 2.)
    elecL.scaling = options.scaleSigL
    elecL.semiinf = options.semiinfL
    elecR = NEGF.ElectrodeSelfEnergy(options.fnR, options.NA1R, options.NA2R,
                                     -options.voltage / 2.)
    elecR.scaling = options.scaleSigR
    elecR.semiinf = options.semiinfR
    DevGF = NEGF.GF(options.TSHS,
                    elecL,
                    elecR,
                    Bulk=options.UseBulk,
                    DeviceAtoms=options.DeviceAtoms,
                    BufferAtoms=options.buffer)
    nspin = DevGF.HS.nspin

    # k-sample only self-energies?
    if options.singlejunction:
        elecL.mesh = mesh
        mesh = Kmesh.kmesh(3, 3, 1)

    if options.dos:
        DOSL = N.zeros((nspin, len(options.Elist), DevGF.nuo), N.float)
        DOSR = N.zeros((nspin, len(options.Elist), DevGF.nuo), N.float)

        # MPSH projections?
        MPSHL = N.zeros((nspin, len(options.Elist), DevGF.nuo), N.float)
        MPSHR = N.zeros((nspin, len(options.Elist), DevGF.nuo), N.float)
        # evaluate eigenstates at Gamma
        import scipy.linalg as SLA
        DevGF.setkpoint(N.zeros(2))
        ev0, es0 = SLA.eigh(DevGF.H, DevGF.S)
        print 'MPSH eigenvalues:', ev0
        #print 'MPSH eigenvector normalizations:',N.diag(MM.mm(MM.dagger(es0),DevGF.S,es0)).real # right

    # Loop over spin
    for iSpin in range(nspin):
        # initialize transmission and shot noise arrays
        Tkpt = N.zeros((len(options.Elist), mesh.NNk, options.numchan + 1),
                       N.float)
        SNkpt = N.zeros((len(options.Elist), mesh.NNk, options.numchan + 1),
                        N.float)
        # prepare output files
        outFile = options.DestDir + '/%s.%ix%i' % (options.systemlabel,
                                                   mesh.Nk[0], mesh.Nk[1])
        if nspin < 2: thisspinlabel = outFile
        else: thisspinlabel = outFile + ['.UP', '.DOWN'][iSpin]
        fo = open(thisspinlabel + '.AVTRANS', 'write')
        fo.write('# Nk1(%s)=%i Nk2(%s)=%i eta=%.2e etaLead=%.2e\n' %
                 (mesh.type[0], mesh.Nk[0], mesh.type[1], mesh.Nk[1],
                  options.eta, options.etaLead))
        fo.write('# E   Ttot(E)   Ti(E)(i=1-%i)   RelErrorTtot(E)\n' %
                 options.numchan)
        foSN = open(thisspinlabel + '.AVNOISE', 'write')
        foSN.write('# Nk1(%s)=%i Nk2(%s)=%i eta=%.2e etaLead=%.2e\n' %
                   (mesh.type[0], mesh.Nk[0], mesh.type[1], mesh.Nk[1],
                    options.eta, options.etaLead))
        foSN.write('# E   SNtot(E)   SNi(E)(i=1-%i)\n' % options.numchan)
        foFF = open(thisspinlabel + '.FANO', 'write')
        foFF.write('# Nk1(%s)=%i Nk2(%s)=%i eta=%.2e etaLead=%.2e\n' %
                   (mesh.type[0], mesh.Nk[0], mesh.type[1], mesh.Nk[1],
                    options.eta, options.etaLead))
        foFF.write('# E   Fano factor \n')
        # Loop over energy
        for ie, ee in enumerate(options.Elist):
            Tavg = N.zeros((options.numchan + 1, len(mesh.w)), N.float)
            SNavg = N.zeros((options.numchan + 1, len(mesh.w)), N.float)
            AavL = N.zeros((DevGF.nuo, DevGF.nuo), N.complex)
            AavR = N.zeros((DevGF.nuo, DevGF.nuo), N.complex)
            # Loops over k-points
            for ik in range(mesh.NNk):
                DevGF.calcGF(ee + options.eta * 1.0j,
                             mesh.k[ik, :2],
                             ispin=iSpin,
                             etaLead=options.etaLead,
                             useSigNCfiles=options.signc,
                             SpectralCutoff=options.SpectralCutoff)
                # Transmission and shot noise
                T, SN = DevGF.calcTEIG(options.numchan)
                for iw in range(len(mesh.w)):
                    Tavg[:, iw] += T * mesh.w[iw, ik]
                    SNavg[:, iw] += SN * mesh.w[iw, ik]
                Tkpt[ie, ik] = T
                SNkpt[ie, ik] = SN
                # DOS calculation:
                if options.dos:
                    if options.SpectralCutoff > 0.0:
                        AavL += mesh.w[0, ik] * MM.mm(DevGF.AL.L, DevGF.AL.R,
                                                      DevGF.S)
                        AavR += mesh.w[0, ik] * MM.mm(DevGF.AR.L, DevGF.AR.R,
                                                      DevGF.S)
                    else:
                        AavL += mesh.w[0, ik] * MM.mm(DevGF.AL, DevGF.S)
                        AavR += mesh.w[0, ik] * MM.mm(DevGF.AR, DevGF.S)
            # Print calculated quantities
            err = (N.abs(Tavg[0, 0] - Tavg[0, 1]) +
                   N.abs(Tavg[0, 0] - Tavg[0, 2])) / 2
            relerr = err / Tavg[0, 0]
            print 'ispin= %i, e= %.4f, Tavg= %.8f, RelErr= %.1e' % (
                iSpin, ee, Tavg[0, 0], relerr)
            transline = '\n%.10f ' % ee
            noiseline = '\n%.10f ' % ee
            for ichan in range(options.numchan + 1):
                if ichan == 0:
                    transline += '%.8e ' % Tavg[ichan, 0]
                    noiseline += '%.8e ' % SNavg[ichan, 0]
                else:
                    transline += '%.4e ' % Tavg[ichan, 0]
                    noiseline += '%.4e ' % SNavg[ichan, 0]
            transline += '%.2e ' % relerr
            fo.write(transline)
            foSN.write(noiseline)
            foFF.write('\n%.10f %.8e' % (ee, SNavg[0, 0] / Tavg[0, 0]))
            # Partial density of states:
            if options.dos:
                DOSL[iSpin, ie, :] += N.diag(AavL).real / (2 * N.pi)
                DOSR[iSpin, ie, :] += N.diag(AavR).real / (2 * N.pi)
                MPSHL[iSpin, ie, :] += N.diag(MM.mm(MM.dagger(es0), AavL,
                                                    es0)).real / (2 * N.pi)
                MPSHR[iSpin, ie, :] += N.diag(MM.mm(MM.dagger(es0), AavR,
                                                    es0)).real / (2 * N.pi)
                print 'ispin= %i, e= %.4f, DOSL= %.4f, DOSR= %.4f' % (
                    iSpin, ee, N.sum(DOSL[iSpin,
                                          ie, :]), N.sum(DOSR[iSpin, ie, :]))
        fo.write('\n')
        fo.close()
        foSN.write('\n')
        foSN.close()
        foFF.write('\n')
        foFF.close()

        # Write k-point-resolved transmission
        fo = open(thisspinlabel + '.TRANS', 'write')
        for ik in range(mesh.NNk):
            w = mesh.w[:, ik]
            fo.write('\n\n# k = %f, %f    w = %f %f %f %f' %
                     (mesh.k[ik, 0], mesh.k[ik, 1], w[0], w[1], w[2], w[3]))
            for ie, ee in enumerate(options.Elist):
                transline = '\n%.10f ' % ee
                for ichan in range(options.numchan + 1):
                    if ichan == 0:
                        transline += '%.8e ' % Tkpt[ie, ik, ichan]
                    else:
                        transline += '%.4e ' % Tkpt[ie, ik, ichan]
                fo.write(transline)
        fo.write('\n')
        fo.close()

        # Write k-point-resolved shot noise
        fo = open(thisspinlabel + '.NOISE', 'write')
        for ik in range(mesh.NNk):
            w = mesh.w[:, ik]
            fo.write('\n\n# k = %f, %f    w = %f %f %f %f' %
                     (mesh.k[ik, 0], mesh.k[ik, 1], w[0], w[1], w[2], w[3]))
            for ie, ee in enumerate(options.Elist):
                noiseline = '\n%.10f ' % ee
                for ichan in range(options.numchan + 1):
                    if ichan == 0:
                        noiseline += '%.8e ' % SNkpt[ie, ik, ichan]
                    else:
                        noiseline += '%.4e ' % SNkpt[ie, ik, ichan]
                fo.write(noiseline)
        fo.write('\n')
        fo.close()

    # End loop over spin
    NEGF.SavedSig.close()  # Make sure saved Sigma is written to file

    if options.dos:
        # Read basis
        L = options.bufferL
        # Pad lasto with zeroes to enable basis generation...
        lasto = N.zeros((DevGF.HS.nua + L + 1, ), N.int)
        lasto[L:] = DevGF.HS.lasto
        basis = SIO.BuildBasis(options.fn, 1 + L, DevGF.HS.nua + L, lasto)
        basis.ii -= L
        WritePDOS(outFile + '.PDOS.gz', options, DevGF, DOSL + DOSR, basis)
        WritePDOS(outFile + '.PDOSL.gz', options, DevGF, DOSL, basis)
        WritePDOS(outFile + '.PDOSR.gz', options, DevGF, DOSR, basis)

        WriteMPSH(outFile + '.MPSH.gz', options, DevGF, MPSHL + MPSHR, ev0)
        WriteMPSH(outFile + '.MPSHL.gz', options, DevGF, MPSHL, ev0)
        WriteMPSH(outFile + '.MPSHR.gz', options, DevGF, MPSHR, ev0)

    CF.PrintMainFooter('pyTBT')
Ejemplo n.º 3
0
def main(options):
    CF.CreatePipeOutput(options.DestDir + '/' + options.Logfile)
    #VC.OptionsCheck(options,'Phonons')

    CF.PrintMainHeader('Bandstructures', options)

    try:
        fdf = glob.glob(options.onlyTSdir + '/RUN.fdf')
        TSrun = True
    except:
        fdf = glob.glob(options.FCwildcard +
                        '/RUN.fdf')  # This should be made an input flag
        TSrun = False
    SCDM = Supercell_DynamicalMatrix(fdf, TSrun)

    # Write high-symmetry path
    WritePath(options.DestDir + '/symmetry-path', SCDM.Sym.path, options.steps)

    # Write mesh
    k1, k2, k3 = ast.literal_eval(options.mesh)
    rvec = 2 * N.pi * N.array([SCDM.Sym.b1, SCDM.Sym.b2, SCDM.Sym.b3])
    import Inelastica.physics.mesh as Kmesh
    # Full mesh
    kmesh = Kmesh.kmesh(2**k1,
                        2**k2,
                        2**k3,
                        meshtype=['LIN', 'LIN', 'LIN'],
                        invsymmetry=False)
    WriteKpoints(options.DestDir + '/mesh_%ix%ix%i' % tuple(kmesh.Nk),
                 N.dot(kmesh.k, rvec))
    # Mesh reduced by inversion symmetry
    kmesh = Kmesh.kmesh(2**k1,
                        2**k2,
                        2**k3,
                        meshtype=['LIN', 'LIN', 'LIN'],
                        invsymmetry=True)
    WriteKpoints(options.DestDir + '/mesh_%ix%ix%i_invsym' % tuple(kmesh.Nk),
                 N.dot(kmesh.k, rvec))

    # Evaluate electron k-points
    if options.kfile:
        # Prepare Hamiltonian etc in Gamma for whole supercell
        natoms = SIO.GetFDFlineWithDefault(fdf[0], 'NumberOfAtoms', int, -1,
                                           'Error')
        SCDM.PrepareGradients(options.onlySdir,
                              N.array([0., 0., 0.]),
                              1,
                              natoms,
                              AbsEref=False,
                              atype=N.complex,
                              TSrun=TSrun)
        SCDM.nao = SCDM.h0.shape[-1]
        SCDM.FirstOrb = SCDM.OrbIndx[0][0]  # First atom = 1
        SCDM.LastOrb = SCDM.OrbIndx[SCDM.Sym.basis.NN -
                                    1][1]  # Last atom = Sym.NN
        SCDM.rednao = SCDM.LastOrb + 1 - SCDM.FirstOrb
        # Read kpoints
        kpts, dk, klabels, kticks = ReadKpoints(options.kfile)
        if klabels:
            # Only write ascii if labels exist
            WriteKpoints(options.DestDir + '/kpoints', kpts, klabels)
        # Prepare netcdf
        ncfn = options.DestDir + '/Electrons.nc'
        ncf = NC4.Dataset(ncfn, 'w')
        # Grid
        ncf.createDimension('gridpts', len(kpts))
        ncf.createDimension('vector', 3)
        grid = ncf.createVariable('grid', 'd', ('gridpts', 'vector'))
        grid[:] = kpts
        grid.units = '1/Angstrom'
        # Geometry
        ncf.createDimension('atoms', SCDM.Sym.basis.NN)
        xyz = ncf.createVariable('xyz', 'd', ('atoms', 'vector'))
        xyz[:] = SCDM.Sym.basis.xyz
        xyz.units = 'Angstrom'
        pbc = ncf.createVariable('pbc', 'd', ('vector', 'vector'))
        pbc.units = 'Angstrom'
        pbc[:] = [SCDM.Sym.a1, SCDM.Sym.a2, SCDM.Sym.a3]
        rvec1 = ncf.createVariable('rvec', 'd', ('vector', 'vector'))
        rvec1.units = '1/Angstrom (incl. factor 2pi)'
        rvec1[:] = rvec
        ncf.sync()
        # Loop over kpoints
        for i, k in enumerate(kpts):
            if i < 100:  # Print only for the first 100 points
                ev, evec = SCDM.ComputeElectronStates(k,
                                                      verbose=True,
                                                      TSrun=TSrun)
            else:
                ev, evec = SCDM.ComputeElectronStates(k,
                                                      verbose=False,
                                                      TSrun=TSrun)
                # otherwise something simple
                if i % 100 == 0:
                    print '%i out of %i k-points computed' % (i, len(kpts))
            if i == 0:
                ncf.createDimension('nspin', SCDM.nspin)
                ncf.createDimension('orbs', SCDM.rednao)
                if options.nbands and options.nbands < SCDM.rednao:
                    nbands = options.nbands
                else:
                    nbands = SCDM.rednao
                ncf.createDimension('bands', nbands)
                evals = ncf.createVariable('eigenvalues', 'd',
                                           ('gridpts', 'nspin', 'bands'))
                evals.units = 'eV'
                evecsRe = ncf.createVariable(
                    'eigenvectors.re', 'd',
                    ('gridpts', 'nspin', 'orbs', 'bands'))
                evecsIm = ncf.createVariable(
                    'eigenvectors.im', 'd',
                    ('gridpts', 'nspin', 'orbs', 'bands'))
                # Check eigenvectors
                print 'SupercellPhonons: Checking eigenvectors at', k
                for j in range(SCDM.nspin):
                    ev2 = N.diagonal(
                        MM.mm(MM.dagger(evec[j]), SCDM.h0_k[j], evec[j]))
                    print ' ... spin %i: Allclose=' % j, N.allclose(ev[j],
                                                                    ev2,
                                                                    atol=1e-5,
                                                                    rtol=1e-3)
                ncf.sync()
            # Write to NetCDF
            evals[i, :] = ev[:, :nbands]
            evecsRe[i, :] = evec[:, :, :nbands].real
            evecsIm[i, :] = evec[:, :, :nbands].imag
        ncf.sync()
        # Include basis orbitals in netcdf file
        if SCDM.Sym.basis.NN == len(SCDM.OrbIndx):
            lasto = N.zeros(SCDM.Sym.basis.NN + 1, N.float)
            lasto[:SCDM.Sym.basis.NN] = SCDM.OrbIndx[:SCDM.Sym.basis.NN, 0]
            lasto[SCDM.Sym.basis.NN] = SCDM.OrbIndx[SCDM.Sym.basis.NN - 1,
                                                    1] + 1
        else:
            lasto = SCDM.OrbIndx[:SCDM.Sym.basis.NN + 1, 0]
        orbbasis = SIO.BuildBasis(fdf[0], 1, SCDM.Sym.basis.NN, lasto)
        # Note that the above basis is for the geometry with an atom FC-moved in z.
        #print dir(orbbasis)
        #print orbbasis.xyz # Hence, this is not the correct geometry of the basis atoms!
        center = ncf.createVariable('orbcenter', 'i', ('orbs', ))
        center[:] = N.array(orbbasis.ii - 1, dtype='int32')
        center.description = 'Atom index (counting from 0) of the orbital center'
        nn = ncf.createVariable('N', 'i', ('orbs', ))
        nn[:] = N.array(orbbasis.N, dtype='int32')
        ll = ncf.createVariable('L', 'i', ('orbs', ))
        ll[:] = N.array(orbbasis.L, dtype='int32')
        mm = ncf.createVariable('M', 'i', ('orbs', ))
        mm[:] = N.array(orbbasis.M, dtype='int32')
        # Cutoff radius and delta
        Rc = ncf.createVariable('Rc', 'd', ('orbs', ))
        Rc[:] = orbbasis.coff
        Rc.units = 'Angstrom'
        delta = ncf.createVariable('delta', 'd', ('orbs', ))
        delta[:] = orbbasis.delta
        delta.units = 'Angstrom'
        # Radial components of the orbitals
        ntb = len(orbbasis.orb[0])
        ncf.createDimension('ntb', ntb)
        rii = ncf.createVariable('rii', 'd', ('orbs', 'ntb'))
        rii[:] = N.outer(orbbasis.delta, N.arange(ntb))
        rii.units = 'Angstrom'
        radialfct = ncf.createVariable('radialfct', 'd', ('orbs', 'ntb'))
        radialfct[:] = orbbasis.orb
        # Sort eigenvalues to connect crossing bands?
        if options.sorting:
            for i in range(SCDM.nspin):
                evals[:, i, :] = SortBands(evals[:, i, :])
        # Produce nice plots if labels exist
        if klabels:
            if SCDM.nspin == 1:
                PlotElectronBands(options.DestDir + '/Electrons.agr', dk,
                                  evals[:, 0, :], kticks)
            elif SCDM.nspin == 2:
                PlotElectronBands(options.DestDir + '/Electrons.UP.agr', dk,
                                  evals[:, 0, :], kticks)
                PlotElectronBands(options.DestDir + '/Electrons.DOWN.agr', dk,
                                  evals[:, 1, :], kticks)
        ncf.close()

    if TSrun:  # only electronic calculation
        return SCDM.Sym.path

    # Compute phonon eigenvalues
    if options.qfile:
        SCDM.SymmetrizeFC(options.radius)
        SCDM.SetMasses()
        qpts, dq, qlabels, qticks = ReadKpoints(options.qfile)
        if qlabels:
            # Only write ascii if labels exist
            WriteKpoints(options.DestDir + '/qpoints', qpts, qlabels)
        # Prepare netcdf
        ncfn = options.DestDir + '/Phonons.nc'
        ncf = NC4.Dataset(ncfn, 'w')
        # Grid
        ncf.createDimension('gridpts', len(qpts))
        ncf.createDimension('vector', 3)
        grid = ncf.createVariable('grid', 'd', ('gridpts', 'vector'))
        grid[:] = qpts
        grid.units = '1/Angstrom'
        # Geometry
        ncf.createDimension('atoms', SCDM.Sym.basis.NN)
        xyz = ncf.createVariable('xyz', 'd', ('atoms', 'vector'))
        xyz[:] = SCDM.Sym.basis.xyz
        xyz.units = 'Angstrom'
        pbc = ncf.createVariable('pbc', 'd', ('vector', 'vector'))
        pbc.units = 'Angstrom'
        pbc[:] = [SCDM.Sym.a1, SCDM.Sym.a2, SCDM.Sym.a3]
        rvec1 = ncf.createVariable('rvec', 'd', ('vector', 'vector'))
        rvec1.units = '1/Angstrom (incl. factor 2pi)'
        rvec1[:] = rvec
        ncf.sync()
        # Loop over q
        for i, q in enumerate(qpts):
            if i < 100:  # Print only for the first 100 points
                hw, U = SCDM.ComputePhononModes_q(q, verbose=True)
            else:
                hw, U = SCDM.ComputePhononModes_q(q, verbose=False)
                # otherwise something simple
                if i % 100 == 0:
                    print '%i out of %i q-points computed' % (i, len(qpts))
            if i == 0:
                ncf.createDimension('bands', len(hw))
                ncf.createDimension('displ', len(hw))
                evals = ncf.createVariable('eigenvalues', 'd',
                                           ('gridpts', 'bands'))
                evals.units = 'eV'
                evecsRe = ncf.createVariable('eigenvectors.re', 'd',
                                             ('gridpts', 'bands', 'displ'))
                evecsIm = ncf.createVariable('eigenvectors.im', 'd',
                                             ('gridpts', 'bands', 'displ'))
                # Check eigenvectors
                print 'SupercellPhonons.Checking eigenvectors at', q
                tmp = MM.mm(N.conjugate(U), SCDM.FCtilde, N.transpose(U))
                const = PC.hbar2SI * (1e20 / (PC.eV2Joule * PC.amu2kg))**0.5
                hw2 = const * N.diagonal(tmp)**0.5  # Units in eV
                print ' ... Allclose=', N.allclose(hw,
                                                   N.absolute(hw2),
                                                   atol=1e-5,
                                                   rtol=1e-3)
                ncf.sync()
            evals[i] = hw
            evecsRe[i] = U.real
            evecsIm[i] = U.imag
        ncf.sync()
        # Sort eigenvalues to connect crossing bands?
        if options.sorting:
            evals = SortBands(evals)
        # Produce nice plots if labels exist
        if qlabels:
            PlotPhononBands(options.DestDir + '/Phonons.agr', dq,
                            N.array(evals[:]), qticks)
        ncf.close()

    # Compute e-ph couplings
    if options.kfile and options.qfile:
        SCDM.ReadGradients(AbsEref=False)
        ncf = NC4.Dataset(options.DestDir + '/EPH.nc', 'w')
        ncf.createDimension('kpts', len(kpts))
        ncf.createDimension('qpts', len(qpts))
        ncf.createDimension('modes', len(hw))
        ncf.createDimension('nspin', SCDM.nspin)
        ncf.createDimension('bands', SCDM.rednao)
        ncf.createDimension('vector', 3)
        kgrid = ncf.createVariable('kpts', 'd', ('kpts', 'vector'))
        kgrid[:] = kpts
        qgrid = ncf.createVariable('qpts', 'd', ('qpts', 'vector'))
        qgrid[:] = qpts
        evalfkq = ncf.createVariable('evalfkq', 'd',
                                     ('kpts', 'qpts', 'nspin', 'bands'))
        # First (second) band index n (n') is the initial (final) state, i.e.,
        # Mkq(k,q,mode,spin,n,n') := < n',k+q | dV_q(mode) | n,k >
        MkqAbs = ncf.createVariable(
            'Mkqabs', 'd',
            ('kpts', 'qpts', 'modes', 'nspin', 'bands', 'bands'))
        GkqAbs = ncf.createVariable(
            'Gkqabs', 'd',
            ('kpts', 'qpts', 'modes', 'nspin', 'bands', 'bands'))
        ncf.sync()
        # Loop over k-points
        for i, k in enumerate(kpts):
            kpts[i] = k
            # Compute initial electronic states
            evi, eveci = SCDM.ComputeElectronStates(k, verbose=True)
            # Loop over q-points
            for j, q in enumerate(qpts):
                # Compute phonon modes
                hw, U = SCDM.ComputePhononModes_q(q, verbose=True)
                # Compute final electronic states
                evf, evecf = SCDM.ComputeElectronStates(k + q, verbose=True)
                evalfkq[i, j, :] = evf
                # Compute electron-phonon couplings
                m, g = SCDM.ComputeEPHcouplings_kq(
                    k, q)  # (modes,nspin,bands,bands)
                # Data to file
                # M (modes,spin,i,l) = m(modes,k,j) init(i,j) final(k,l)
                #                            0 1 2       0,1        0 1
                #                                ^-------^
                #                              ^----------------------^
                for ispin in range(SCDM.nspin):
                    evecfd = MM.dagger(evecf[ispin])  # (bands,bands)
                    M = N.tensordot(N.tensordot(m[:, ispin],
                                                eveci[ispin],
                                                axes=[2, 0]),
                                    evecfd,
                                    axes=[1, 1])
                    G = N.tensordot(N.tensordot(g[:, ispin],
                                                eveci[ispin],
                                                axes=[2, 0]),
                                    evecfd,
                                    axes=[1, 1])
                    MkqAbs[i, j, :, ispin] = N.absolute(M)
                    GkqAbs[i, j, :, ispin] = N.absolute(G)
                ncf.sync()
        ncf.close()
    return SCDM.Sym.path
Ejemplo n.º 4
0
def main(options):
    """
    Main routine to compute eigenchannel scattering states

    Parameters
    ----------
    options : an ``options`` instance
    """

    CF.CreatePipeOutput(options.DestDir+'/'+options.Logfile)
    VC.OptionsCheck(options, 'EigenChannels')
    CF.PrintMainHeader('EigenChannels', options)

    # Read geometry
    XV = '%s/%s.XV'%(options.head, options.systemlabel)
    geom = MG.Geom(XV, BufferAtoms=options.buffer)

    # Set up device Greens function
    elecL = NEGF.ElectrodeSelfEnergy(options.fnL, options.NA1L, options.NA2L, options.voltage/2.)
    elecL.scaling = options.scaleSigL
    elecL.semiinf = options.semiinfL
    elecR = NEGF.ElectrodeSelfEnergy(options.fnR, options.NA1R, options.NA2R, -options.voltage/2.)
    elecR.scaling = options.scaleSigR
    elecR.semiinf = options.semiinfR
    DevGF = NEGF.GF(options.TSHS, elecL, elecR, Bulk=options.UseBulk,
                    DeviceAtoms=options.DeviceAtoms,
                    BufferAtoms=options.buffer)
    DevGF.calcGF(options.energy+options.eta*1.0j, options.kpoint[0:2], ispin=options.iSpin,
                 etaLead=options.etaLead, useSigNCfiles=options.signc, SpectralCutoff=options.SpectralCutoff)
    NEGF.SavedSig.close() # Make sure saved Sigma is written to file

    # Transmission
    print 'Transmission Ttot(%.4feV) = %.16f'%(options.energy, N.trace(DevGF.TT).real)

    # Build basis
    options.nspin = DevGF.HS.nspin
    L = options.bufferL
    # Pad lasto with zeroes to enable basis generation...
    lasto = N.zeros((DevGF.HS.nua+L+1,), N.int)
    lasto[L:] = DevGF.HS.lasto
    basis = SIO.BuildBasis(options.fn,
                           options.DeviceAtoms[0]+L,
                           options.DeviceAtoms[1]+L, lasto)
    basis.ii -= L

    # Calculate Eigenchannels
    DevGF.calcEigChan(options.numchan)

    # Compute bond currents?
    if options.kpoint[0]!=0.0 or options.kpoint[1]!=0.0:
        print 'Warning: The current implementation of bond currents is only valid for the Gamma point (should be easy to fix)'
        BC = False
    else:
        BC = True

    # Eigenchannels from left
    ECleft = DevGF.ECleft
    for jj in range(options.numchan):
        options.iSide, options.iChan = 0, jj+1
        writeWavefunction(options, geom, basis, ECleft[jj])
        if BC:
            Curr=calcCurrent(options, basis, DevGF.H, ECleft[jj])
            writeCurrent(options, geom, Curr)

    # Calculate eigenchannels from right
    if options.bothsides:
        ECright = DevGF.ECright
        for jj in range(options.numchan):
            options.iSide, options.iChan = 1, jj+1
            writeWavefunction(options, geom, basis, ECright[jj])
            if BC:
                Curr=calcCurrent(options, basis, DevGF.H, ECright[jj])
                writeCurrent(options, geom, Curr)

    # Calculate total "bond currents"
    if BC:
        Curr=-calcCurrent(options, basis, DevGF.H, DevGF.AL)
        options.iChan, options.iSide = 0, 0
        writeCurrent(options, geom, Curr)
        Curr=-calcCurrent(options, basis, DevGF.H, DevGF.AR)
        options.iSide = 1
        writeCurrent(options, geom, Curr)

    # Calculate eigenstates of device Hamiltonian (MPSH)
    if options.MolStates>0.0:
        try:
            import scipy.linalg as SLA
            ev, es = SLA.eigh(DevGF.H, DevGF.S)
            print 'EigenChannels: Eigenvalues (in eV) of computed molecular eigenstates:'
            print ev
            # Write eigenvalues to file
            fn = options.DestDir+'/'+options.systemlabel+'.EIGVAL'
            print 'EigenChannels: Writing', fn
            fnfile = open(fn, 'w')
            fnfile.write('# Device region = [%i,%i], units in eV\n'%(options.DeviceFirst, options.DeviceLast))
            for i, val in enumerate(ev):
                fnfile.write('%i %.8f\n'%(i, val))
            fnfile.close()
            # Compute selected eigenstates
            for ii, val in enumerate(ev):
                if N.abs(val)<options.MolStates:
                    fn=options.DestDir+'/'+options.systemlabel+'.S%.3i.E%.3f'%(ii, val)
                    writeWavefunction(options, geom, basis, es[:, ii], fn=fn)
        except:
            print 'You need to install scipy to solve the generalized eigenvalue problem'
            print 'for the molecular eigenstates in the nonorthogonal basis'

    CF.PrintMainFooter('EigenChannels')
Ejemplo n.º 5
0
def main(options):
    dd = len(glob.glob(options.DestDir))
    if len(glob.glob('TotalPotential.grid.nc'))==0 and len(glob.glob('Rho.grid.nc'))==0:
        sys.exit('TotalPotential.nc and Rho.grid.nc not found! Add "SaveTotalPotential true" and "SaveRho true" to RUN.fdf')
    if len(glob.glob('TotalPotential.grid.nc'))==0:
        sys.exit('TotalPotential.nc not found! Add "SaveTotalPotential true" to RUN.fdf')
    if len(glob.glob('Rho.grid.nc'))==0:
        sys.exit('Rho.grid.nc not found! Add "SaveRho true" to RUN.fdf')

    CF.CreatePipeOutput(options.DestDir+'/'+options.Logfile)
    VC.OptionsCheck(options, 'STM')
    CF.PrintMainHeader('STM', options)

    ## Step 1: Calculate scattering states from L/R on TranSiesta real space grid.
    if glob.glob(options.DestDir+'/kpoints')!=[]: # Check previous k-points
        f, oldk = open(options.DestDir+'/kpoints', 'r'), []
        f.readline()
        for ii in f.readlines():
            oldk += [N.array(string.split(ii), N.float)]
        oldk = N.array(oldk)

    options.kpoints.mesh2file(options.DestDir+'/kpoints')
    doK = []
    for ikpoint in range(len(options.kpoints.k)):
        ikdir = options.DestDir+'/%i'%(ikpoint)
        if not os.path.isdir(ikdir):
            os.mkdir(ikdir)
        doK += [ikpoint]

    #Check if some k points are already done
    doK = []
    nokpts = len(options.kpoints.k)
    noFDcalcs = len(glob.glob('./'+options.DestDir+'/*/FDcurr*.nc'))
    for ii in range(nokpts):
        if len(glob.glob('./'+options.DestDir+'/'+str(ii)+'/FDcurr'+str(ii)+'.nc'))==1:
            pass
        else:
            doK += [ii]

    if noFDcalcs>nokpts-1:
        print('\nAll ('+str(nokpts)+') k points are already finished!\n')
    elif noFDcalcs>0 and noFDcalcs<nokpts:
        print(str(nokpts-len(doK))+' ('+str(N.round(100.*((1.*nokpts-len(doK))/nokpts), 1))+'%) k points already done. Will proceed with the rest.')
        print('You should perhaps remove the loc-basis states in the most recent k folder ')
        print('since some of these may not have been calculated before interuption.\n')
    else:
        if dd==1:
            print('No STM calculations found in existing directory '+str(options.DestDir)+'/. Starting from scratch.')
            print('(...by possibly using saved localized-basis states)\n')
        else:
            print('STM calculation starts.')
    args=[(options, ik) for ik in doK]
    tmp = CF.runParallel(calcTSWFPar, args, nCPU=options.nCPU)

    print('Calculating k-point averaged STM image')
    def ShiftOrigin(mat, x, y):
        Nx = N.shape(mat)[0]; Ny = N.shape(mat)[1]
        NewMat = N.zeros((Nx, Ny))
        for ii in range(Nx):
            for jj in range(Ny):
                NewMat[N.mod(ii+x, Nx), N.mod(jj+y, Ny)] = mat[ii, jj]
        return NewMat

    file = NC.Dataset('TotalPotential.grid.nc', 'r')
    steps = N.array(file.variables['cell'][:], N.float)
    theta = N.arccos(N.dot(steps[0], steps[1])/(LA.norm(steps[0])*LA.norm(steps[1])))

    currtmp = NC.Dataset('./'+options.DestDir+'/0/FDcurr0.nc', 'r')
    dimSTMimage = N.shape(currtmp.variables['Curr'][:, :])
    dim1 = dimSTMimage[0]
    dim2 = dimSTMimage[1]
    STMimage = N.zeros((dim1, dim2))
    tmpSTM = N.zeros((dim1*nokpts, dim2))
    for ii in range(nokpts):
        file = NC.Dataset('./'+options.DestDir+'/'+str(ii)+'/FDcurr'+str(ii)+'.nc', 'r')
        ikSTMimage = file.variables['Curr'][:, :]/(nokpts)
        STMimage += ShiftOrigin(ikSTMimage, dim1/2, dim2/2)
        tmpSTM[ii*dim1:(ii+1)*dim1, :] = ShiftOrigin(ikSTMimage, dim1/2, dim2/2)
    STMimagekpt = N.zeros((dim1*options.Nk1, dim2*options.Nk2))
    for ii in range(options.Nk1):
        for jj in range(options.Nk2):
            N1 = ii+1; N2 = options.Nk2-jj; kk = (ii+1)*options.Nk2-jj-1
            STMimagekpt[(N1-1)*dim1:N1*dim1, (N2-1)*dim2:N2*dim2]=tmpSTM[kk*dim1:(kk+1)*dim1, ::-1]

    tmp = open(options.systemlabel+'.XV').readlines()[4+options.DeviceFirst-1:4+options.DeviceLast]
    xyz = N.zeros((len(tmp), 4))
    for ii in range(len(tmp)):
        for jj in range(1, 5):
            tmp2 = tmp[ii].split()
            xyz[ii, jj-1] = ast.literal_eval(tmp2[jj])
            if jj>1:
                xyz[ii, jj-1] = xyz[ii, jj-1]*PC.Bohr2Ang

    drAtoms = N.zeros(len(xyz))
    for atomIdx in range(len(xyz)-1):
        drAtoms[atomIdx] = N.round((xyz[atomIdx+1][3]-xyz[atomIdx][3]), 3)
    TipHeight = N.max(drAtoms)

    n=writeNC.NCfile('./'+options.DestDir+'/STMimage.nc')
    n.write(STMimage, 'STMimage')
    n.write(theta, 'theta')
    n.write(options.kpoints.k, 'kpoints')
    n.write(options.Nk1, 'Nk1')
    n.write(options.Nk2, 'Nk2')
    n.write(STMimagekpt, 'STMkpoint')
    n.write(xyz, 'Geometry')
    n.write(TipHeight, 'TipHeight')
    n.close()

    CF.PrintMainFooter('STM')