Groundstate

Element: groundstate

The groundstate element is required for any calculation. Its attributes are parameters and methods which are used to calculate the ground-state density.

 contains: DFTD2parameters (optional) TSvdWparameters (optional) spin (optional) dfthalf (optional) Hybrid (optional) solver (optional) OEP (optional) output (optional) libxc (optional) XPath: /input/groundstate

Attribute: CoreRelativity

Chooses between relativistic/non-relativistic descriptions for core electrons. Pick either "dirac" or "none".

 Type: choose from: dirac none Default: "dirac" Use: optional XPath: /input/groundstate/@CoreRelativity

Attribute: ExplicitKineticEnergy

If true, the kinetic energy expectation values are calculated explicitly and, then, they are used for calculating the total energy.

 Type: boolean Default: "true" Use: optional XPath: /input/groundstate/@ExplicitKineticEnergy

Attribute: PrelimLinSteps

After which SCF iteration is msec mixing supposed to be turned on. Until then linear mixing is applied. Used in msec mixing as choosen with mixer.

 Type: integer Default: "2" Use: optional XPath: /input/groundstate/@PrelimLinSteps

Attribute: SymmetricKineticEnergy

If "true", the kinetic-energy matrix elements of muffin-tin functions are calculated by applying gradient to both bra and ket. Otherwise, the whole kinetic-energy operator is applied to ket only, and the surface-term correction is applied to make the hamiltonian hermitian.

 Type: boolean Default: "true" Use: optional XPath: /input/groundstate/@SymmetricKineticEnergy

Attribute: ValenceRelativity

Relativistic Hamiltonian to use in groundstate calculations.

• none - solves non-relativistic Schoedinger equation (SE)
• zora - solves scalar-relativistic SE within zero-order regular approximation (ZORA)
• iora* - solves scalar-relativistic SE within infinite-order regular approximation (IORA), the small component is neglected
• iora - solves scalar-relativistic SE within infinite-order regular approximation (IORA), the small component is included
• kh* - solves scalar-relativistic SE for the large component, the small component is neglected
• kh - solves scalar-relativistic SE for the large component, the small component is included

iora, kh* and kh are implemented only for atoms.

 Type: choose from: zora iora* iora kh* kh none Default: "zora" Use: optional XPath: /input/groundstate/@ValenceRelativity

Attribute: autokpt

If "true", the set of k-points is determined automatically according to radkpt.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@autokpt

Attribute: beta0

Initial value for mixing parameter. Used in linear mixing as choosen with mixer.

 Type: fortrandouble Default: "0.4d0" Use: optional XPath: /input/groundstate/@beta0

Mixing parameter decrease. Used in linear mixing.

 Type: fortrandouble Default: "0.6d0" Use: optional XPath: /input/groundstate/@betadec

Attribute: betainc

Mixing parameter increase. Used in linear mixing.

 Type: fortrandouble Default: "1.1d0" Use: optional XPath: /input/groundstate/@betainc

Attribute: cfdamp

Damping coefficient for characteristic function.

 Type: fortrandouble Default: "0.0d0" Use: optional XPath: /input/groundstate/@cfdamp

Attribute: chgexs

This controls the amount of charge in the unit cell beyond that required to maintain neutrality. It can be set positive or negative depending on whether electron or hole doping is required.

 Type: fortrandouble Default: "0.0d0" Use: optional XPath: /input/groundstate/@chgexs

Attribute: deband

Initial band energy step size The initial step length used when searching for the band energy, which is used as the APW linearisation energy. This is done by first searching upwards in energy until the radial wave-function at the muffin-tin radius is zero. This is the energy at the top of the band, denoted $E_{\rm t}$. A downward search is now performed from $E_{\rm t}$ until the slope of the radial wave-function at the muffin-tin radius is zero. This energy, $E_{\rm b}$, is at the bottom of the band. The band energy is taken as $(E_{\rm t}+E_{\rm b})/2$. If either $E_{\rm t}$ or $E_{\rm b}$ cannot be found then the band energy is set to the default value.

 Type: fortrandouble Default: "0.0025d0" Use: optional Unit: Hartree XPath: /input/groundstate/@deband

Attribute: dipolecorrection

If "true", the dipole correction is applied for slabs oriented along the $z$-direction.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@dipolecorrection

Attribute: dipoleposition

The value of this attribute indicates the position of the jump in electrostatic potential, after the compensating potential (i.e., the dipole correction) is applied. The position is given as a fractional coordinate in the vertical direction. Please note that this jump position should be located within the vacuum region enough far away from the atomic layers, otherwise the compensating potential cannot be correctly applied. It is recommended to put the jump position at the middle of the vacuum layer.

 Type: fortrandouble Default: "1.0d0" Use: optional XPath: /input/groundstate/@dipoleposition

Attribute: dlinengyfermi

Energy difference between linearisation and Fermi energy.

 Type: fortrandouble Default: "-0.1d0" Use: optional Unit: Hartree XPath: /input/groundstate/@dlinengyfermi

Attribute: do

Decides if the ground state is calculated starting from scratch, using the densities from file, or if its calculation is skipped and only the associated input parameters are read in.

 Type: choose from: fromscratch fromfile skip Default: "fromscratch" Use: optional XPath: /input/groundstate/@do

Attribute: energyref

Energy reference $\varepsilon_\textrm{ref}$ for the scalar-relativistic ZORA. It enters the kinetic energy expression $T=\mathbf{p}\frac{c^2}{2c^2+\varepsilon-v(\mathbf{r})}\mathbf{p}$.

 Type: fortrandouble Default: "0.0d0" Use: optional XPath: /input/groundstate/@energyref

Attribute: epsband

Energy tolerance for search of linearisation energies.

 Type: fortrandouble Default: "1.0d-6" Use: optional Unit: Hartree XPath: /input/groundstate/@epsband

Attribute: epschg

Convergence criterion for the maximum allowed error in the calculated total charge beyond which a warning message will be issued.

 Type: fortrandouble Default: "1.0d-5" Use: optional XPath: /input/groundstate/@epschg

Attribute: epsengy

Energy convergence tolerance.

 Type: fortrandouble Default: "1.0d-6" Use: optional Unit: Hartree XPath: /input/groundstate/@epsengy

Attribute: epsforcescf

Convergence tolerance for forces (not including IBS contribution) during the SCF run.

 Type: fortrandouble Default: "5.0d-5" Use: optional XPath: /input/groundstate/@epsforcescf

Attribute: epsocc

smallest occupancy for which a state will contribute to the density.

 Type: fortrandouble Default: "1.0d-8" Use: optional XPath: /input/groundstate/@epsocc

Attribute: epspot

If the RMS change in the effective potential and magnetic field is smaller than epspot, then the self-consistent loop is considered converged and exited. For structural optimization runs this results in the forces being calculated, the atomic positions updated and the loop restarted. See also maxscl.

 Type: fortrandouble Default: "1.0d-6" Use: optional XPath: /input/groundstate/@epspot

Attribute: fermilinengy

If "true" the linearization energies marked as non-varying are set to the Fermi level plus dlinengyfermi.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@fermilinengy

Attribute: findlinentype

Select method to determine the linearisation energies.

 Type: choose from: Wigner_Seitz lcharge logderiv no_search Default: "Wigner_Seitz" Use: optional XPath: /input/groundstate/@findlinentype

Attribute: fracinr

Fraction of the muffin-tin radius up to which lmaxinr is used as the angular momentum cut-off.

 Type: fortrandouble Default: "0.02d0" Use: optional XPath: /input/groundstate/@fracinr

Attribute: frozencore

When set to "true" the frozen core approximation is applied, i.e., the core states are fixed to the atomic states.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@frozencore

Attribute: gmaxvr

Maximum length of |G| for expanding the interstitial density and potential.

 Type: fortrandouble Default: "12.0d0" Use: optional XPath: /input/groundstate/@gmaxvr

Attribute: isgkmax

Species for which the muffin-tin radius will be used for calculating gkmax.

 Type: integer Default: "-1" Use: optional XPath: /input/groundstate/@isgkmax

Attribute: ldapu

Type of LDA+U method to be used.

 Type: choose from: none FullyLocalisedLimit AroundMeanField FFL-AMF-interpolation Default: "none" Use: optional XPath: /input/groundstate/@ldapu

Attribute: lmaxapw

Angular momentum cut-off for the APW functions.

 Type: integer Default: "8" Use: optional XPath: /input/groundstate/@lmaxapw

Attribute: lmaxinr

Close to the nucleus, the density and potential is almost spherical and therefore the spherical harmonic expansion can be truncated a low angular momentum. See also fracinr.

 Type: integer Default: "2" Use: optional XPath: /input/groundstate/@lmaxinr

Attribute: lmaxmat

Angular momentum cut-off for the outer-most loop in the hamiltonian and overlap matrix setup.

 Type: integer Default: "8" Use: optional XPath: /input/groundstate/@lmaxmat

Attribute: lmaxvr

Angular momentum cut-off for the muffin-tin density and potential.

 Type: integer Default: "8" Use: optional XPath: /input/groundstate/@lmaxvr

Attribute: lorecommendation

Local orbitals may be used for improving unoccupied states. But what energy parameters to use? Set this parameter to true, and you will get a list of energies at which the radial wavefunction turns to zero on the muffin-tin sphere. These energies are calculated using atomic potential, and to make them transferable to a general system, use the average of two consecutive atomic energies.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@lorecommendation

Some muffin-tin functions (such as the density) are calculated on a coarse radial mesh and then interpolated onto a fine mesh. This is done for the sake of efficiency. lradstp defines the step size in going from the fine to the coarse radial mesh. If it is too large, loss of precision may occur.

 Type: integer Default: "1" Use: optional XPath: /input/groundstate/@lradstep

Attribute: maxscl

Upper limit for the self-consistency loop.

 Type: integer Default: "200" Use: optional XPath: /input/groundstate/@maxscl

Attribute: mixer

Select the mixing (relaxation) scheme for the SCF loop. One has the following options:

Linear mixer ("lin"):

Given the input $\mu^i$ and output $\nu^i$ vectors of the $i$th iteration, the next input vector to the ($i+1$)th iteration is generated using an adaptive mixing scheme. The $j$th component of the output vector is mixed with a fraction of the same component of the input vector:

(1)
\begin{align} \mu^{i+1}_j=\beta^i_j\nu^i_j+(1-\beta^i_j)\mu^i_j, \end{align}

where $\beta^i_j$ is set to $\beta_0$ at initialisation and increased by scaling with $\beta_{\rm inc}$ ($>1$) if $f^i_j\equiv\nu^i_j-\mu^i_j$ does not change sign between loops. If $f^i_j$ does change sign, then $\beta^i_j$ is scaled by $\beta_{\rm dec}$ ($>1$).

Multisecant Broyden potential mixing ("msec")

Pulay mixing ("pulay"):

Pulay's mixing scheme which uses direct inversion in the iterative subspace (DIIS). See Chem. Phys. Lett. 73, 393 (1980).

 Type: choose from: lin msec pulay Default: "msec" Use: optional XPath: /input/groundstate/@mixer

Attribute: mixerswitch

Switch between potential (1) and density (2) mixing.

 Type: integer Default: "1" Use: optional XPath: /input/groundstate/@mixerswitch

Attribute: modifiedsv

If "true", the construction of the second-variational hamiltonian involves wavefunctions in the basis representation and wavefunctions are not evaluated explicitly. Otherwise, the usual second-variational procedure is used. The first of the two approaches is generally recommended, but it is not implemented for non-collinear and LDA+U calculations.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@modifiedsv

Attribute: msecStoredSteps

How many potentials from previous steps to store. Used in msec mixing as choosen with mixer.

 Type: integer Default: "8" Use: optional XPath: /input/groundstate/@msecStoredSteps

Attribute: nempty

Defines the number of eigenstates beyond that required for charge neutrality. When running metals it is not known a priori how many states will be below the Fermi energy for each k-point. Setting nempty greater than zero allows the additional states to act as a buffer in such cases. Furthermore, magnetic calculations use the first-variational eigenstates as a basis for setting up the second-variational Hamiltonian, and thus nempty will determine the size of this basis set. Convergence with respect to this quantity should be checked.

 Type: integer Default: "5" Use: optional XPath: /input/groundstate/@nempty

Attribute: ngridk

Number of k grid points along the basis vector directions. Alternatively give autokpt and radkpt, or nktot. In the latter cases any value given for ngridk is not used. Notes: Phonon calculations using supercells adjust the k-grid according to the supercell size; if the element xs is given, the present attribute is overwritten by the value in xs for xs-related groundstate calculations; the values of the present attribute are also relevant for calculations related to the element gw.

 Type: integertriple Default: "1 1 1" Use: optional XPath: /input/groundstate/@ngridk

Attribute: niterconvcheck

Number of self-consistency iterations over which to test convergence. For example, if niterconvcheck=2, then both the second and third to last iterations are compared to the last one to check convergence. The convergence criteria used are those set up by scfconv.

 Type: integer Default: "2" Use: optional XPath: /input/groundstate/@niterconvcheck

Attribute: nktot

Used for the automatic determination of the ${\mathbf k}$-point mesh from the total number of k-points. If nktot is set, then the mesh will be determined in such a way that the number of k-points is proportional to the length of the reciprocal lattice vector in each direction and that the total number of k-points is less than or equal to nktot.

 Type: integer Default: "0" Use: optional XPath: /input/groundstate/@nktot

Attribute: nosource

When set to "true", source fields are projected out of the exchange-correlation magnetic field. experimental feature.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@nosource

Attribute: nosym

When set to "true" no symmetries, apart from the identity, are used anywhere in the code.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@nosym

(Obsolete) Order of predictor-corrector polynomial.

 Type: integer Default: "4" Use: optional XPath: /input/groundstate/@nprad

Attribute: npsden

Order of polynomial for pseudo-charge density.

 Type: integer Default: "9" Use: optional XPath: /input/groundstate/@npsden

Attribute: nwrite

Normally, the density and potentials are written to the file STATE.OUT only after completion of the self-consistent loop. By setting nwrite to a positive integer the file will be written during the loop every nwrite iterations.

 Type: integer Default: "0" Use: optional XPath: /input/groundstate/@nwrite

Attribute: outputlevel

Specify amount of information which is printed to files:

• none - no output is produced
• low - minimal output is produced
• normal - (default) standard information
• high - detailed output
 Type: choose from: none low normal high Default: "normal" Use: optional XPath: /input/groundstate/@outputlevel

Attribute: ptnucl

The attrubute ptnucl is "true" if the nuclei are to be treated as point charges, if "false" the nuclei have a finite spherical distribution.

 Type: boolean Default: "true" Use: optional XPath: /input/groundstate/@ptnucl

The parameter defines a functional form how radial-grid points are distributed. Choose from "cubic", "exponential" and "expocubic". "cubic" is the most suitable one for a majority of calculations, but switch to "expocubic" if you set the innermost grid point very close to a nucleus.

 Type: string Default: "cubic" Use: optional XPath: /input/groundstate/@radialgridtype

Used for the automatic determination of the k-point mesh. If autokpt is set to "true" then the mesh sizes will be determined by $n_i=\lambda/|{ \bf A}_i|+1$.

 Type: fortrandouble Default: "40.0d0" Use: optional XPath: /input/groundstate/@radkpt

Attribute: reducek

If the attribute reducek is "true" the $\bf{k}$-point set is reduced with the crystal symmetries.

 Type: boolean Default: "true" Use: optional XPath: /input/groundstate/@reducek

Attribute: rgkmax

The parameter rgkmax implicitly determines the number of basis functions and is one of the crucial parameters for the accuracy of the calculation. It represents the product of two quantities: $R_{MT,\, Min}$, the smallest of all muffin-tin radii, and $|{ \bf G}+{ \bf k}|_{max}$, the maximum length for the ${ \bf G}+{ \bf k}$ vectors. Because each ${ \bf G}+{ \bf k}$ vector represents one basis function, rgkmax gives the number of basis functions used for solving the Kohn-Sham equations. Typical values of rgkmax are between 6 and 9. However, for systems with very short bond-lengths, significantly smaller values may be sufficient. This may especially be the case for materials containing carbon, where rgkmax may be 4.5-5, or hydrogen, where even values between 3 and 4 may be sufficient. In any case, a convergence check is indispensible for a proper choice of this parameter for your system!

 Type: fortrandouble Default: "7.0d0" Use: optional XPath: /input/groundstate/@rgkmax

Attribute: scfconv

Specify the SCF convergence criteria

• "energy" - only the total energy of the system is used as a convergence criterion. If the calculation of the atomic forces is required (e.g., in the optimization of the atomic positions) the non-IBS contribution to the atomic forces is added as a further convergence criterion.
• "potential" - only the Kohn-Sham potential is used as a convergence criterion. If atomic forces are required the convergence criterion is extended to include non-IBS forces.
• "multiple" - total energy, Kohn-Sham potential, and total electronic charge of the system are used as convergence criteria. If atomic forces are required the convergence criterion is extended to include non-IBS forces.
 Type: string Default: "multiple" Use: optional XPath: /input/groundstate/@scfconv

Attribute: stype

A smooth approximation to the Dirac delta function is needed to compute the occupancies of the Kohn-Sham states. The attribute swidth determines the width of the approximate delta function.

 Type: choose from: Gaussian Methfessel-Paxton 1 Methfessel-Paxton 2 Fermi Dirac Square-wave impulse libbzint Default: "Gaussian" Use: optional XPath: /input/groundstate/@stype

Attribute: swidth

Width of the smooth approximation to the Dirac delta function (must be greater than zero).

 Type: fortrandouble Default: "0.001d0" Use: optional Unit: Hartree XPath: /input/groundstate/@swidth

Attribute: symmorph

When set to "true" only symmorphic space-group operations are to be considered, i.e. only symmetries without non-primitive translations are used anywhere in the code.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@symmorph

Attribute: tevecsv

The attribute tevecsv is "true" if second-variational eigenvectors are calculated.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@tevecsv

Attribute: tfibs

Because calculation of the incomplete basis set (IBS) correction to the force is fairly time- consuming, it can be switched off by setting tfibs to "false" This correction can then be included only when necessary, i.e. when the atoms are close to equilibrium in a structural relaxation run.

 Type: boolean Default: "true" Use: optional XPath: /input/groundstate/@tfibs

Attribute: tforce

Decides if the force should be calculated at the end of the self-consistent cycle.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@tforce

Attribute: tpartcharges

The attribute tpartcharges is "true" if partial charges for each state j, atom alpha and for each lm combination are calculated.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/@tpartcharges

Attribute: vdWcorrection

Adds dispersion (van-der-Waals) correction to total energy after the last SCF iteration. If forces are calculated, an appropriate dispersion correction is applied. Available methods are

• "DFTD2": This is the DFT-D2 method by Stefan Grimme which is introduced in Semiempirical GGA-type density functional constructed with a long-range dispersion correction, J. Comput. Chem. 27, 1787-1799 (2006).
• "TSvdW": This is the TS-vdW method by Alexandre Tkatchenko and Matthias Scheffler introduced in Accurate molecular van-der-Waals interactions from ground-state electron density and free-atom reference data, Phys. Rev. Lett. 102, 073005 (2009).

Parameters corresponding to each method can be specified using the subelements DFTD2parameters and TSvdWparameters inside the element groundstate. It is also possible to decouple these van-der-Waals corrections from a complete ground-state calculation. In this case, you can use the subelements DFTD2 and TSvdW inside the element properties.

 Type: choose from: none DFTD2 TSvdW Default: "none" Use: optional XPath: /input/groundstate/@vdWcorrection

Attribute: vkloff

The ${\mathbf k}$-point offset vector in lattice coordinates.

 Type: vect3d Default: "0.0d0 0.0d0 0.0d0" Use: optional XPath: /input/groundstate/@vkloff

Attribute: xctype

Type of exchange-correlation functional to be used

• No exchange-correlation funtional ( $E_{\rm xc}\equiv 0$ )
• LDA, Perdew-Zunger/Ceperley-Alder, Phys. Rev. B 23, 5048 (1981)
• LSDA, Perdew-Wang/Ceperley-Alder, Phys. Rev. B 45, 13244 (1992)
• LDA, X-alpha approximation, J. C. Slater, Phys. Rev. 81, 385 (1951)
• LSDA, von Barth-Hedin, J. Phys. C 5, 1629 (1972)
• GGA, Perdew-Burke-Ernzerhof (PBE), Phys. Rev. Lett. 77, 3865 (1996)
• GGA, Revised PBE, Zhang-Yang, Phys. Rev. Lett. 80, 890 (1998)
• GGA, PBEsol, arXiv:0707.2088v1 (2007)
• GGA, asymptotically corrected PBE (acPBE), arXiv:1409.4834 (2014)
• GGA, Wu-Cohen exchange (WC06) with PBE correlation, Phys. Rev. B 73, 235116 (2006)
• GGA, Armiento-Mattsson (AM05) spin-unpolarised functional, Phys. Rev. B 72, 085108 (2005)
• EXX, Exact Exchange, Phys. Rev. Lett. 95, 136402 (2005)
• Hybrid, PBE0, J. Chem. Phys. 110, 5029 (1999)
 Type: choose from: LDA_PZ LDA_PW LDA_XALPHA LDA_vBH GGA_PBE GGA_PBE_R GGA_PBE_SOL GGA_WC GGA_AM05 GGA_AC_PBE HYB_PBE0 HYB_LDA0 EXX none Default: "GGA_PBE" Use: optional XPath: /input/groundstate/@xctype

Element: DFTD2parameters

This element allows to customize parameters when either the option "DFTD2" of the attribute vdWcorrection is chosen, or the subelement DFTD2 of the element properties is specified.

 Type: no content XPath: /input/groundstate/DFTD2parameters

This element allows for specification of the following attributes: cutoff, d, s6, sr6

Attribute: cutoff

Cutoff distance of interatomic interactions for the method "DFTD2". In the sum over all pairwise interactions, only pairs of atoms are considered which are closer to each other than the value of the cutoff attribute.

 Type: fortrandouble Default: "95.0d0" Use: optional XPath: /input/groundstate/DFTD2parameters/@cutoff

Attribute: d

This damping constant determines the steepnes of the damping function for the method "DFTD2".

 Type: fortrandouble Default: "20.0d0" Use: optional XPath: /input/groundstate/DFTD2parameters/@d

Attribute: s6

Global scaling factor for all $C_6$-dispersion coefficients for the method "DFTD2". This factor depends on the exchange-correlation functional in use. The default value suits PBE calculations.

 Type: fortrandouble Default: "0.75d0" Use: optional XPath: /input/groundstate/DFTD2parameters/@s6

Attribute: sr6

Scaling factor for van-der-Waals radii for the method "DFTD2". This factor depends on the exchange-correlation functional in use. The default value suits PBE calculations.

 Type: fortrandouble Default: "1.1d0" Use: optional XPath: /input/groundstate/DFTD2parameters/@sr6

Element: TSvdWparameters

This element allows to customize parameters when either the option "TSvdW" of the attribute vdWcorrection is chosen, or the subelement TSvdW of the element properties is specified.

 Type: no content XPath: /input/groundstate/TSvdWparameters

This element allows for specification of the following attributes: cutoff, d, nr, nsph, s6, sr6

Attribute: cutoff

Cutoff distance of interatomic interactions for the method "TSvdW". In the sum over all pairwise interactions, only pairs of atoms are considered which are closer to each other than the value of the cutoff attribute.

 Type: fortrandouble Default: "95.0d0" Use: optional XPath: /input/groundstate/TSvdWparameters/@cutoff

Attribute: d

This damping constant determines the steepnes of the damping function for the method "TSvdW".

 Type: fortrandouble Default: "20.0d0" Use: optional XPath: /input/groundstate/TSvdWparameters/@d

Attribute: nr

 Type: integer Default: "120" Use: optional XPath: /input/groundstate/TSvdWparameters/@nr

Attribute: nsph

Number of Lebedev grid points. The only possible values are: "1", "6", "14", "26", "38", "50", "74", "86", "110", "146", "170", "194", "230", "266", "302", "350", "434", "590", "770", "974", "1202", "1454", "1730", "2030", "2354", "2702", "3074", "3740", "3890", "4334", "4802", "5294", "5810".

 Type: integer Default: "590" Use: optional XPath: /input/groundstate/TSvdWparameters/@nsph

Attribute: s6

Global scaling factor for all $C_6$-dispersion coefficients for the method "TSvdW".

 Type: fortrandouble Default: "1.0d0" Use: optional XPath: /input/groundstate/TSvdWparameters/@s6

Attribute: sr6

Scaling factor for van-der-Waals radii for the method "TSvdW". This factor depends on the exchange-correlation functional in use. The default value suits PBE calculations.

 Type: fortrandouble Default: "0.94d0" Use: optional XPath: /input/groundstate/TSvdWparameters/@sr6

Element: spin

If the spin element is present, calculation is done with spin polarization.

 Type: no content XPath: /input/groundstate/spin

This element allows for specification of the following attributes: bfieldc, fixspin, momfix, reducebf, spinorb, spinsprl, taufsm, vqlss

Attribute: bfieldc

Allows to apply a constant ${ \bf B}_{\tt ext}$ field. This is an external constant magnetic field applied throughout the entire unit cell and enters the second-variational Hamiltonian as

(2)
\begin{align} \frac{g_e\,\alpha}{4}\;\vec{\sigma}\cdot{\bf B}_{\tt ext}\,, \end{align}

where $g_e$ is the electron $g$-factor ($g_e$=2.0023193043718). The external magnetic field is normally used to break spin symmetry for spin-polarised calculations and considered to be infinitesimal with no direct contribution to the total energy. In cases where the magnetic field is finite (for example when computing magnetic response) the external ${ \bf B}$-field energy reported in INFO.OUT (when the attribute outputlevel is set to"high") should be added to the total energy by hand. This external magnetic field is applied hroughout the entire unit cell. To apply magnetic fields in particular muffin-tins use the bfcmt vectors in the atom elements. Collinear calculations are more efficient if the field is applied in the $z$-direction.

 Type: vect3d Default: "0.0d0 0.0d0 0.0d0 " Use: optional XPath: /input/groundstate/spin/@bfieldc

Attribute: fixspin

 Type: choose from: none total FSM localmt FSM both Default: "none" Use: optional XPath: /input/groundstate/spin/@fixspin

Attribute: momfix

The desired total moment for a fixed spin moment (FSM) calculation.

 Type: vect3d Default: "0.0d0 0.0d0 0.0d0" Use: optional XPath: /input/groundstate/spin/@momfix

Attribute: reducebf

After each iteration the external magnetic fields are multiplied with reducebf. This allows for a large external magnetic field at the start of the self-consistent loop to break spin symmetry, while at the end of the loop the field will be effectively zero, i.e. infinitesimal. See bfieldc and atom element.

 Type: fortrandouble Default: "1.0d0" Use: optional XPath: /input/groundstate/spin/@reducebf

Attribute: spinorb

If spinorb is "true", then a $\boldsymbol \sigma\cdot{ \bf L}$ term is added to the second-variational Hamiltonian.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/spin/@spinorb

Attribute: spinsprl

Set to "true" if a spin-spiral calculation is required. Experimental feature for the calculation of spin-spiral states. See vqlss for details.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/spin/@spinsprl

Attribute: taufsm

The effective magnetic field required for fixing the spin moment to a given value, is updated according to

(3)
\begin{align} {\bf B}_{\tt FSM}^{i+1}={\bf B}_{\tt FSM}^i+\tau_{\tt FSM}\left( \boldsymbol{\mu}^i-\boldsymbol{\mu}_{\tt FSM}\right)\,, \end{align}

for iteration $i$. It must be positive.

 Type: fortrandouble Default: "0.01d0" Use: optional XPath: /input/groundstate/spin/@taufsm

Attribute: vqlss

This attribute allows to specify the ${ \bf q}$-vector of the spin-spiral state in lattice coordinates. Spin-spirals arise from spinor states assumed to be of the form

(4)
\begin{align} \Psi^{ \bf q}_{ \bf k}({ \bf r})= \left(\begin{array}{c} U^{{ \bf q}\uparrow}_{ \bf k}({ \bf r})\;e^{i({ \bf k+q/2})\cdot{ \bf r}} \\ \phantom{o} \\ U^{{ \bf q}\downarrow}_{ \bf k}({ \bf r})\;e^{i({ \bf k-q/2})\cdot{ \bf r}} \\ \end{array} \right)\,. \end{align}

These spin-spirals are determined using a second-variational approach, and give rise to a magnetization density of the form

(5)
\begin{align} {\bf m}^{ \bf q}({ \bf r})=\left[m_x({\bf r})\,\cos({ \bf q \cdot r}),\; m_y({\bf r})\,\sin({ \bf q \cdot r}),\; m_z({\bf r})\right]\,, \end{align}

where $m_x$, $m_y$, and $m_z$ have the periodicity of the lattice. See also spinsprl.

 Type: vect3d Default: "0.0d0 0.0d0 0.0d0" Use: optional XPath: /input/groundstate/spin/@vqlss

Element: dfthalf

The presence of this element triggers DFT-1/2 calculations.

 Type: no content XPath: /input/groundstate/dfthalf

This element allows for specification of the following attributes: printVSfile

Attribute: printVSfile

When set to "true", the self-energy correction potential $V_S({\bf r})$ (as defined in the DFT-1/2 method) is calculated for each constituent atomic species and written into the files VS_S*.OUT, where * ranges from 1 to the number of atomic species. The exciting run quits after the printing. In this case, a serial calculation is suggested. It is useful to visualize the self-energy potential, or for debugging purposes.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/dfthalf/@printVSfile

Element: Hybrid

Options for hybrid functionals.

 Type: no content XPath: /input/groundstate/Hybrid

This element allows for specification of the following attributes: exchangetype, excoeff, maxscl

Attribute: exchangetype

Type of exchange (Hartree Fock or OEP) to be used for the exact exchange.

 Type: choose from: HF OEP Default: "HF" Use: optional XPath: /input/groundstate/Hybrid/@exchangetype

Attribute: excoeff

Define value of the mixing parameter for exact exchange. ATTENTION: If you are using libxc, the libxc settings will be employed and your choice of this parameter will be ignored.

 Type: fortrandouble Default: "0.25d0" Use: optional XPath: /input/groundstate/Hybrid/@excoeff

Attribute: maxscl

Upper limit for the Hybrids self-consistency loop.

 Type: integer Default: "50" Use: optional XPath: /input/groundstate/Hybrid/@maxscl

Element: solver

Optional configuration options for eigenvector solver.

 Type: no content XPath: /input/groundstate/solver

This element allows for specification of the following attributes: ArpackImproveInverse, ArpackLinSolve, ArpackShift, ArpackUserDefinedShift, DecompPrec, epsarpack, evaltol, packedmatrixstorage, type

Attribute: ArpackImproveInverse

Tells whether iterative improvement should be applied during the shift-and-invert procedure. Setting to true may be useful, for instance, when DecompPrec is set to "sp".

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/solver/@ArpackImproveInverse

Attribute: ArpackLinSolve

Linear solve method during shift-and-invert process in ARPACK. Pick either LDL, LU, LL, Diag and InvertOnce.

 Type: choose from: LDL LL LU Diag InvertOnce Default: "LDL" Use: optional XPath: /input/groundstate/solver/@ArpackLinSolve

Attribute: ArpackShift

Energy shift in the shift-and-invert procedure in the ARPACK solver.

 Type: fortrandouble Default: "-1.0d0" Use: optional Unit: Hartree XPath: /input/groundstate/solver/@ArpackShift

Attribute: ArpackUserDefinedShift

ArpackShift will be used if this flag is set to true, otherwise the energy shift will be determined internally.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/solver/@ArpackUserDefinedShift

Attribute: DecompPrec

Precision used during the factorization in ARPACK. Pick either sp or dp.

 Type: choose from: sp dp Default: "dp" Use: optional XPath: /input/groundstate/solver/@DecompPrec

Attribute: epsarpack

Tolerance parameter for the ARPACK shift invert solver

 Type: fortrandouble Default: "1.0d-14" Use: optional XPath: /input/groundstate/solver/@epsarpack

Attribute: evaltol

Error tolerance for the first-variational eigenvalues using the LAPACK Solver

 Type: fortrandouble Default: "1.0d-14" Use: optional Unit: Hartree XPath: /input/groundstate/solver/@evaltol

Attribute: packedmatrixstorage

In the default calculation the matrix is sored in packed form. When using multi-threaded BLAS setting this parameter to "false" increases efficiency.

 Type: boolean Default: "false" Use: optional XPath: /input/groundstate/solver/@packedmatrixstorage

Attribute: type

Selects the eigenvalue solver for the first variational equation

 Type: choose from: Lapack Arpack Default: "Lapack" Use: optional XPath: /input/groundstate/solver/@type

Element: OEP

Necessary, if exact exchange calculation is to be performed.

 Type: no content XPath: /input/groundstate/OEP

This element allows for specification of the following attributes: convoep, maxitoep, tauoep

Attribute: convoep

Convergence tolerance for OEP residue when solving the exact exchange integral equations.

 Type: fortrandouble Default: "1e-11" Use: optional XPath: /input/groundstate/OEP/@convoep

Attribute: maxitoep

Maximum number of iterations when solving the exact exchange integral equations.

 Type: integer Default: "300" Use: optional XPath: /input/groundstate/OEP/@maxitoep

Attribute: tauoep

The optimised effective potential is determined using an iterative method. Phys. Rev. Lett. 98, 196405 (2007). At the first iteration the step length is set to tauoep(1). During subsequent iterations, the step length is scaled by tauoep(2) or tauoep(3), when the residual is increasing or decreasing, respectively. See also maxitoep.

 Type: vect3d Default: "1.0d0 0.2d0 1.5d0" Use: optional XPath: /input/groundstate/OEP/@tauoep

Element: output

Specifications on the file formats for output files.

 Type: no content XPath: /input/groundstate/output

This element allows for specification of the following attributes: state

Attribute: state

Selects the file format of the STATE file.

 Type: choose from: binary XML Default: "binary" Use: optional XPath: /input/groundstate/output/@state

Element: libxc

 Type: no content XPath: /input/groundstate/libxc

This element allows for specification of the following attributes: correlation, exchange, xc

Attribute: correlation

 Type: choose from: none XC_LDA_C_WIGNER XC_LDA_C_RPA XC_LDA_C_HL XC_LDA_C_GL XC_LDA_C_XALPHA XC_LDA_C_VWN XC_LDA_C_VWN_RPA XC_LDA_C_PZ XC_LDA_C_PZ_MOD XC_LDA_C_OB_PZ XC_LDA_C_PW XC_LDA_C_PW_MOD XC_LDA_C_OB_PW XC_LDA_C_2D_AMGB XC_LDA_C_2D_PRM XC_LDA_C_vBH XC_LDA_C_1D_CSC XC_LDA_C_ML1 XC_LDA_C_ML2 XC_LDA_C_GOMBAS XC_LDA_C_PW_RPA XC_LDA_C_1D_LOOS XC_LDA_C_RC04 XC_LDA_C_VWN_1 XC_LDA_C_VWN_2 XC_LDA_C_VWN_3 XC_LDA_C_VWN_4 XC_GGA_C_OP_XALPHA XC_GGA_C_OP_G96 XC_GGA_C_OP_PBE XC_GGA_C_OP_B88 XC_GGA_C_FT97 XC_GGA_C_SPBE XC_GGA_C_REVTCA XC_GGA_C_TCA XC_GGA_C_PBE XC_GGA_C_LYP XC_GGA_C_P86 XC_GGA_C_PBE_SOL XC_GGA_C_PW91 XC_GGA_C_AM05 XC_GGA_C_XPBE XC_GGA_C_LM XC_GGA_C_PBE_JRGX XC_GGA_C_RGE2 XC_GGA_C_WL XC_GGA_C_WI XC_GGA_C_SOGGA11 XC_GGA_C_WI0 XC_GGA_C_SOGGA11_X XC_GGA_C_APBE XC_GGA_C_OPTC Default: "XC_GGA_C_PBE" Use: optional XPath: /input/groundstate/libxc/@correlation

Attribute: exchange

 Type: choose from: none XC_LDA_X XC_LDA_X_2D XC_LDA_X_1D XC_GGA_X_SSB_SW XC_GGA_X_SSB XC_GGA_X_SSB_D XC_GGA_X_BPCCAC XC_GGA_X_PBE XC_GGA_X_PBE_R XC_GGA_X_B86 XC_GGA_X_HERMAN XC_GGA_X_B86_MGC XC_GGA_X_B88 XC_GGA_X_G96 XC_GGA_X_PW86 XC_GGA_X_PW91 XC_GGA_X_OPTX XC_GGA_X_DK87_R1 XC_GGA_X_DK87_R2 XC_GGA_X_LG93 XC_GGA_X_FT97_A XC_GGA_X_FT97_B XC_GGA_X_PBE_SOL XC_GGA_X_RPBE XC_GGA_X_WC XC_GGA_X_MPW91 XC_GGA_X_AM05 XC_GGA_X_PBEA XC_GGA_X_MPBE XC_GGA_X_XPBE XC_GGA_X_2D_B86_MGC XC_GGA_X_BAYESIAN XC_GGA_X_PBE_JSJR XC_GGA_X_2D_B88 XC_GGA_X_2D_B86 XC_GGA_X_2D_PBE XC_GGA_X_OPTB88_VDW XC_GGA_X_PBEK1_VDW XC_GGA_X_OPTPBE_VDW XC_GGA_X_RGE2 XC_GGA_X_RPW86 XC_GGA_X_KT1 XC_GGA_X_MB88 XC_GGA_X_SOGGA XC_GGA_X_SOGGA11 XC_GGA_X_C09X XC_GGA_X_LB XC_GGA_X_LBM XC_GGA_X_OL2 XC_GGA_X_APBE XC_GGA_X_HTBS XC_GGA_X_AIRY XC_GGA_X_LAG Default: "XC_GGA_X_PBE" Use: optional XPath: /input/groundstate/libxc/@exchange

Attribute: xc

Combined functionals. If set it overrides the exchange and the correlation attributes.

 Type: choose from: none XC_LDA_XC_TETER93 XC_GGA_XC_HCTH_407P XC_GGA_XC_HCTH_P76 XC_GGA_XC_HCTH_P14 XC_GGA_XC_B97_GGA1 XC_GGA_XC_HCTH_A XC_GGA_XC_KT2 XC_GGA_XC_TH1 XC_GGA_XC_TH2 XC_GGA_XC_TH3 XC_GGA_XC_TH4 XC_GGA_XC_HCTH_93 XC_GGA_XC_HCTH_120 XC_GGA_XC_HCTH_147 XC_GGA_XC_HCTH_407 XC_GGA_XC_EDF1 XC_GGA_XC_XLYP XC_GGA_XC_B97 XC_GGA_XC_B97_1 XC_GGA_XC_B97_2 XC_GGA_XC_B97_D XC_GGA_XC_B97_K XC_GGA_XC_B97_3 XC_GGA_XC_PBE1W XC_GGA_XC_MPWLYP1W XC_GGA_XC_PBELYP1W XC_GGA_XC_SB98_1a XC_GGA_XC_SB98_1b XC_GGA_XC_SB98_1c XC_GGA_XC_SB98_2a XC_GGA_XC_SB98_2b XC_GGA_XC_SB98_2c XC_GGA_XC_MOHLYP XC_GGA_XC_MOHLYP2 XC_GGA_XC_TH_FL XC_GGA_XC_TH_FC XC_GGA_XC_TH_FCFO XC_GGA_XC_TH_FCO XC_HYB_GGA_XC_B3PW91 XC_HYB_GGA_XC_B3LYP XC_HYB_GGA_XC_B3P86 XC_HYB_GGA_XC_O3LYP XC_HYB_GGA_XC_mPW1K XC_HYB_GGA_XC_PBEH XC_HYB_GGA_XC_B97 XC_HYB_GGA_XC_B97_1 XC_HYB_GGA_XC_B97_2 XC_HYB_GGA_XC_X3LYP XC_HYB_GGA_XC_B1WC XC_HYB_GGA_XC_B97_K XC_HYB_GGA_XC_B97_3 XC_HYB_GGA_XC_MPW3PW XC_HYB_GGA_XC_B1LYP XC_HYB_GGA_XC_B1PW91 XC_HYB_GGA_XC_mPW1PW XC_HYB_GGA_XC_MPW3LYP XC_HYB_GGA_XC_SB98_1a XC_HYB_GGA_XC_SB98_1b XC_HYB_GGA_XC_SB98_1c XC_HYB_GGA_XC_SB98_2a XC_HYB_GGA_XC_SB98_2b XC_HYB_GGA_XC_SB98_2c XC_HYB_GGA_XC_BHANDH XC_HYB_GGA_XC_BHANDHLYP XC_HYB_GGA_XC_MB3LYP_RC04 Default: "none" Use: optional XPath: /input/groundstate/libxc/@xc

Reused Elements

The following elements can occur more than once in the input file. There for they are listed separately.

Data Types

The Input definition uses derived data types. These are described here.