X

Name Xalpha
Section Hamiltonian::XC
Type float
Default 1.0

The parameter of the Slater X$\alpha$ functional. Applies only for XCFunctional = xc_lda_c_xalpha.

Name XCDensityCorrection
Section Hamiltonian::XC::DensityCorrection
Type integer
Default none

This variable controls the long-range correction of the XC potential using the XC density representation.

Options:

• none:
  No correction is applied.
  
• long_range_x:
  The correction is applied to the exchange potential.
  

Name XCDensityCorrectionCutoff
Section Hamiltonian::XC::DensityCorrection
Type float
Default 0.0

The value of the cutoff applied to the XC density.

Name XCDensityCorrectionMinimum
Section Hamiltonian::XC::DensityCorrection
Type logical
Default true

When enabled, the cutoff optimization will return the first minimum of the $q_{xc}$ function if it does not find a value of -1 (details). This is required for atoms or small molecules, but may cause numerical problems.

Name XCDensityCorrectionNormalize
Section Hamiltonian::XC::DensityCorrection
Type logical
Default true

When enabled, the correction will be normalized to reproduce the exact boundary conditions of the XC potential.

Name XCDensityCorrectionOptimize
Section Hamiltonian::XC::DensityCorrection
Type logical
Default true

When enabled, the density cutoff will be optimized to replicate the boundary conditions of the exact XC potential. If the variable is set to no, the value of the cutoff must be given by the XCDensityCorrectionCutoff variable.

Name XCFunctional
Section Hamiltonian::XC
Type integer

Defines the exchange and correlation functionals to be used, specified as a sum of an exchange functional and a correlation functional, or a single exchange-correlation functional (e.g. hyb_gga_xc_pbeh). For more information on the functionals, see Libxc documentation. The list provided here is from libxc 4; if you have linked against a different libxc version, you may have a somewhat different set of available functionals. Note that kinetic-energy functionals are not supported.

The default functional will be selected by Octopus to be consistent with the pseudopotentials you are using. If you are not using pseudopotentials, Octopus cannot determine the functional used to generate the pseudopotential, or the pseudopotential functionals are inconsistent, Octopus will use the following defaults:

1D: lda_x_1d + lda_c_1d_csc
2D: lda_x_2d + lda_c_2d_amgb
3D: lda_x + lda_c_pz_mod

Options:

• lda_x:
  Exchange
  
• lda_c_wigner:
  Wigner parametrization
  
• lda_c_rpa:
  Random Phase Approximation
  
• lda_c_hl:
  Hedin & Lundqvist
  
• lda_c_gl:
  Gunnarson & Lundqvist
  
• lda_c_xalpha:
  Slater Xalpha
  
• lda_c_vwn:
  Vosko, Wilk, & Nusair (5)
  
• lda_c_vwn_rpa:
  Vosko, Wilk, & Nusair (RPA)
  
• lda_c_pz:
  Perdew & Zunger
  
• lda_c_pz_mod:
  Perdew & Zunger (Modified)
  
• lda_c_ob_pz:
  Ortiz & Ballone (PZ)
  
• lda_c_pw:
  Perdew & Wang
  
• lda_c_pw_mod:
  Perdew & Wang (Modified)
  
• lda_c_ob_pw:
  Ortiz & Ballone (PW)
  
• lda_c_2d_amgb:
  Attaccalite et al
  
• lda_c_2d_prm:
  Pittalis, Rasanen & Marques correlation in 2D
  
• lda_c_vbh:
  von Barth & Hedin
  
• lda_c_1d_csc:
  Casula, Sorella, and Senatore 1D correlation
  
• lda_x_2d:
  Exchange in 2D
  
• lda_xc_teter93:
  Teter 93 parametrization
  
• lda_x_1d:
  Exchange in 1D
  
• lda_c_ml1:
  Modified LSD (version 1) of Proynov and Salahub
  
• lda_c_ml2:
  Modified LSD (version 2) of Proynov and Salahub
  
• lda_c_gombas:
  Gombas parametrization
  
• lda_c_pw_rpa:
  Perdew & Wang fit of the RPA
  
• lda_c_1d_loos:
  P-F Loos correlation LDA
  
• lda_c_rc04:
  Ragot-Cortona
  
• lda_c_vwn_1:
  Vosko, Wilk, & Nusair (1)
  
• lda_c_vwn_2:
  Vosko, Wilk, & Nusair (2)
  
• lda_c_vwn_3:
  Vosko, Wilk, & Nusair (3)
  
• lda_c_vwn_4:
  Vosko, Wilk, & Nusair (4)
  
• lda_xc_zlp:
  Zhao, Levy & Parr, Eq. (20)
  
• lda_xc_ksdt:
  Karasiev et al. parametrization
  
• lda_c_chachiyo:
  Chachiyo simple 2 parameter correlation
  
• lda_c_lp96:
  Liu-Parr correlation
  
• lda_x_rel:
  Relativistic exchange
  
• lda_xc_1d_ehwlrg_1:
  LDA constructed from slab-like systems of 1 electron
  
• lda_xc_1d_ehwlrg_2:
  LDA constructed from slab-like systems of 2 electrons
  
• lda_xc_1d_ehwlrg_3:
  LDA constructed from slab-like systems of 3 electrons
  
• lda_x_erf:
  Attenuated exchange LDA (erf)
  
• lda_xc_lp_a:
  Lee-Parr reparametrization B
  
• lda_xc_lp_b:
  Lee-Parr reparametrization B
  
• lda_x_rae:
  Rae self-energy corrected exchange
  
• lda_c_mcweeny:
  McWeeny 76
  
• lda_c_br78:
  Brual & Rothstein 78
  
• lda_c_pk09:
  Proynov and Kong 2009
  
• lda_c_ow_lyp:
  Wigner with corresponding LYP parameters
  
• lda_c_ow:
  Optimized Wigner
  
• lda_xc_gdsmfb:
  Groth et al. parametrization
  
• lda_c_gk72:
  Gordon and Kim 1972
  
• lda_c_karasiev:
  Karasiev reparameterization of Chachiyo
  
• gga_x_gam:
  GAM functional from Minnesota
  
• gga_c_gam:
  GAM functional from Minnesota
  
• gga_x_hcth_a:
  HCTH-A
  
• gga_x_ev93:
  Engel and Vosko
  
• gga_x_bcgp:
  Burke, Cancio, Gould, and Pittalis
  
• gga_c_bcgp:
  Burke, Cancio, Gould, and Pittalis
  
• gga_x_lambda_oc2_n:
  lambda_OC2(N) version of PBE
  
• gga_x_b86_r:
  Revised Becke 86 Xalpha,beta,gamma (with mod. grad. correction)
  
• gga_x_lambda_ch_n:
  lambda_CH(N) version of PBE
  
• gga_x_lambda_lo_n:
  lambda_LO(N) version of PBE
  
• gga_x_hjs_b88_v2:
  HJS screened exchange corrected B88 version
  
• gga_c_q2d:
  Chiodo et al
  
• gga_x_q2d:
  Chiodo et al
  
• gga_x_pbe_mol:
  Del Campo, Gazquez, Trickey and Vela (PBE-like)
  
• gga_x_ak13:
  Armiento & Kuemmel 2013
  
• gga_x_lv_rpw86:
  Berland and Hyldgaard
  
• gga_x_pbe_tca:
  PBE revised by Tognetti et al
  
• gga_x_pbeint:
  PBE for hybrid interfaces
  
• gga_c_zpbeint:
  spin-dependent gradient correction to PBEint
  
• gga_c_pbeint:
  PBE for hybrid interfaces
  
• gga_c_zpbesol:
  spin-dependent gradient correction to PBEsol
  
• gga_xc_opbe_d:
  oPBE_D functional of Goerigk and Grimme
  
• gga_xc_opwlyp_d:
  oPWLYP-D functional of Goerigk and Grimme
  
• gga_xc_oblyp_d:
  oBLYP-D functional of Goerigk and Grimme
  
• gga_x_vmt84_ge:
  VMT{8,4} with constraint satisfaction with mu = mu_GE
  
• gga_x_vmt84_pbe:
  VMT{8,4} with constraint satisfaction with mu = mu_PBE
  
• gga_x_vmt_ge:
  Vela, Medel, and Trickey with mu = mu_GE
  
• gga_x_vmt_pbe:
  Vela, Medel, and Trickey with mu = mu_PBE
  
• gga_c_n12_sx:
  N12-SX functional from Minnesota
  
• gga_c_n12:
  N12 functional from Minnesota
  
• gga_x_n12:
  N12 functional from Minnesota
  
• gga_c_regtpss:
  Regularized TPSS correlation (ex-VPBE)
  
• gga_c_op_xalpha:
  one-parameter progressive functional (XALPHA version)
  
• gga_c_op_g96:
  one-parameter progressive functional (G96 version)
  
• gga_c_op_pbe:
  one-parameter progressive functional (PBE version)
  
• gga_c_op_b88:
  one-parameter progressive functional (B88 version)
  
• gga_c_ft97:
  Filatov & Thiel correlation
  
• gga_c_spbe:
  PBE correlation to be used with the SSB exchange
  
• gga_x_ssb_sw:
  Swart, Sola and Bickelhaupt correction to PBE
  
• gga_x_ssb:
  Swart, Sola and Bickelhaupt
  
• gga_x_ssb_d:
  Swart, Sola and Bickelhaupt dispersion
  
• gga_xc_hcth_407p:
  HCTH/407+
  
• gga_xc_hcth_p76:
  HCTH p=7/6
  
• gga_xc_hcth_p14:
  HCTH p=1/4
  
• gga_xc_b97_gga1:
  Becke 97 GGA-1
  
• gga_c_hcth_a:
  HCTH-A
  
• gga_x_bpccac:
  BPCCAC (GRAC for the energy)
  
• gga_c_revtca:
  Tognetti, Cortona, Adamo (revised)
  
• gga_c_tca:
  Tognetti, Cortona, Adamo
  
• gga_x_pbe:
  Perdew, Burke & Ernzerhof exchange
  
• gga_x_pbe_r:
  Perdew, Burke & Ernzerhof exchange (revised)
  
• gga_x_b86:
  Becke 86 Xalpha,beta,gamma
  
• gga_x_herman:
  Herman et al original GGA
  
• gga_x_b86_mgc:
  Becke 86 Xalpha,beta,gamma (with mod. grad. correction)
  
• gga_x_b88:
  Becke 88
  
• gga_x_g96:
  Gill 96
  
• gga_x_pw86:
  Perdew & Wang 86
  
• gga_x_pw91:
  Perdew & Wang 91
  
• gga_x_optx:
  Handy & Cohen OPTX 01
  
• gga_x_dk87_r1:
  dePristo & Kress 87 (version R1)
  
• gga_x_dk87_r2:
  dePristo & Kress 87 (version R2)
  
• gga_x_lg93:
  Lacks & Gordon 93
  
• gga_x_ft97_a:
  Filatov & Thiel 97 (version A)
  
• gga_x_ft97_b:
  Filatov & Thiel 97 (version B)
  
• gga_x_pbe_sol:
  Perdew, Burke & Ernzerhof exchange (solids)
  
• gga_x_rpbe:
  Hammer, Hansen & Norskov (PBE-like)
  
• gga_x_wc:
  Wu & Cohen
  
• gga_x_mpw91:
  Modified form of PW91 by Adamo & Barone
  
• gga_x_am05:
  Armiento & Mattsson 05 exchange
  
• gga_x_pbea:
  Madsen (PBE-like)
  
• gga_x_mpbe:
  Adamo & Barone modification to PBE
  
• gga_x_xpbe:
  xPBE reparametrization by Xu & Goddard
  
• gga_x_2d_b86_mgc:
  Becke 86 MGC for 2D systems
  
• gga_x_bayesian:
  Bayesian best fit for the enhancement factor
  
• gga_x_pbe_jsjr:
  JSJR reparametrization by Pedroza, Silva & Capelle
  
• gga_x_2d_b88:
  Becke 88 in 2D
  
• gga_x_2d_b86:
  Becke 86 Xalpha,beta,gamma
  
• gga_x_2d_pbe:
  Perdew, Burke & Ernzerhof exchange in 2D
  
• gga_c_pbe:
  Perdew, Burke & Ernzerhof correlation
  
• gga_c_lyp:
  Lee, Yang & Parr
  
• gga_c_p86:
  Perdew 86
  
• gga_c_pbe_sol:
  Perdew, Burke & Ernzerhof correlation SOL
  
• gga_c_pw91:
  Perdew & Wang 91
  
• gga_c_am05:
  Armiento & Mattsson 05 correlation
  
• gga_c_xpbe:
  xPBE reparametrization by Xu & Goddard
  
• gga_c_lm:
  Langreth and Mehl correlation
  
• gga_c_pbe_jrgx:
  JRGX reparametrization by Pedroza, Silva & Capelle
  
• gga_x_optb88_vdw:
  Becke 88 reoptimized to be used with vdW functional of Dion et al
  
• gga_x_pbek1_vdw:
  PBE reparametrization for vdW
  
• gga_x_optpbe_vdw:
  PBE reparametrization for vdW
  
• gga_x_rge2:
  Regularized PBE
  
• gga_c_rge2:
  Regularized PBE
  
• gga_x_rpw86:
  refitted Perdew & Wang 86
  
• gga_x_kt1:
  Exchange part of Keal and Tozer version 1
  
• gga_xc_kt2:
  Keal and Tozer version 2
  
• gga_c_wl:
  Wilson & Levy
  
• gga_c_wi:
  Wilson & Ivanov
  
• gga_x_mb88:
  Modified Becke 88 for proton transfer
  
• gga_x_sogga:
  Second-order generalized gradient approximation
  
• gga_x_sogga11:
  Second-order generalized gradient approximation 2011
  
• gga_c_sogga11:
  Second-order generalized gradient approximation 2011
  
• gga_c_wi0:
  Wilson & Ivanov initial version
  
• gga_xc_th1:
  Tozer and Handy v. 1
  
• gga_xc_th2:
  Tozer and Handy v. 2
  
• gga_xc_th3:
  Tozer and Handy v. 3
  
• gga_xc_th4:
  Tozer and Handy v. 4
  
• gga_x_c09x:
  C09x to be used with the VdW of Rutgers-Chalmers
  
• gga_c_sogga11_x:
  To be used with HYB_GGA_X_SOGGA11_X
  
• gga_x_lb:
  van Leeuwen & Baerends
  
• gga_xc_hcth_93:
  HCTH functional fitted to 93 molecules
  
• gga_xc_hcth_120:
  HCTH functional fitted to 120 molecules
  
• gga_xc_hcth_147:
  HCTH functional fitted to 147 molecules
  
• gga_xc_hcth_407:
  HCTH functional fitted to 407 molecules
  
• gga_xc_edf1:
  Empirical functionals from Adamson, Gill, and Pople
  
• gga_xc_xlyp:
  XLYP functional
  
• gga_xc_kt1:
  Keal and Tozer version 1
  
• gga_xc_b97_d:
  Grimme functional to be used with C6 vdW term
  
• gga_xc_pbe1w:
  Functionals fitted for water
  
• gga_xc_mpwlyp1w:
  Functionals fitted for water
  
• gga_xc_pbelyp1w:
  Functionals fitted for water
  
• gga_x_lbm:
  van Leeuwen & Baerends modified
  
• gga_x_ol2:
  Exchange form based on Ou-Yang and Levy v.2
  
• gga_x_apbe:
  mu fixed from the semiclassical neutral atom
  
• gga_c_apbe:
  mu fixed from the semiclassical neutral atom
  
• gga_x_htbs:
  Haas, Tran, Blaha, and Schwarz
  
• gga_x_airy:
  Constantin et al based on the Airy gas
  
• gga_x_lag:
  Local Airy Gas
  
• gga_xc_mohlyp:
  Functional for organometallic chemistry
  
• gga_xc_mohlyp2:
  Functional for barrier heights
  
• gga_xc_th_fl:
  Tozer and Handy v. FL
  
• gga_xc_th_fc:
  Tozer and Handy v. FC
  
• gga_xc_th_fcfo:
  Tozer and Handy v. FCFO
  
• gga_xc_th_fco:
  Tozer and Handy v. FCO
  
• gga_c_optc:
  Optimized correlation functional of Cohen and Handy
  
• gga_c_pbeloc:
  Semilocal dynamical correlation
  
• gga_xc_vv10:
  Vydrov and Van Voorhis
  
• gga_c_pbefe:
  PBE for formation energies
  
• gga_c_op_pw91:
  one-parameter progressive functional (PW91 version)
  
• gga_x_pbefe:
  PBE for formation energies
  
• gga_x_cap:
  Correct Asymptotic Potential
  
• gga_x_eb88:
  Non-empirical (excogitated) B88 functional of Becke and Elliott
  
• gga_c_pbe_mol:
  Del Campo, Gazquez, Trickey and Vela (PBE-like)
  
• gga_c_bmk:
  Boese-Martin for kinetics
  
• gga_c_tau_hcth:
  correlation part of tau-hcth
  
• gga_c_hyb_tau_hcth:
  correlation part of hyb_tau-hcth
  
• gga_x_beefvdw:
  BEEF-vdW exchange
  
• gga_xc_beefvdw:
  BEEF-vdW exchange-correlation
  
• gga_x_pbetrans:
  Gradient-based interpolation between PBE and revPBE
  
• gga_x_chachiyo:
  Chachiyo exchange
  
• gga_x_wpbeh:
  short-range version of the PBE
  
• gga_x_hjs_pbe:
  HJS screened exchange PBE version
  
• gga_x_hjs_pbe_sol:
  HJS screened exchange PBE_SOL version
  
• gga_x_hjs_b88:
  HJS screened exchange B88 version
  
• gga_x_hjs_b97x:
  HJS screened exchange B97x version
  
• gga_x_ityh:
  short-range recipe for exchange GGA functionals
  
• gga_x_sfat:
  short-range recipe for exchange GGA functionals
  
• gga_x_sg4:
  Semiclassical GGA at fourth order
  
• gga_c_sg4:
  Semiclassical GGA at fourth order
  
• gga_x_gg99:
  Gilbert and Gill 1999
  
• gga_x_pbepow:
  PBE power
  
• gga_x_kgg99:
  Gilbert and Gill 1999 (mixed)
  
• gga_xc_hle16:
  high local exchange 2016
  
• gga_c_scan_e0:
  GGA component of SCAN
  
• gga_c_gapc:
  GapC
  
• gga_c_gaploc:
  Gaploc
  
• gga_c_zvpbeint:
  another spin-dependent correction to PBEint
  
• gga_c_zvpbesol:
  another spin-dependent correction to PBEsol
  
• gga_c_tm_lyp:
  Takkar and McCarthy reparametrization
  
• gga_c_tm_pbe:
  Thakkar and McCarthy reparametrization
  
• gga_c_w94:
  Wilson 94 (Eq. 25)
  
• gga_c_cs1:
  A dynamical correlation functional
  
• gga_x_b88m:
  Becke 88 reoptimized to be used with mgga_c_tau1
  
• hyb_gga_x_n12_sx:
  N12-SX functional from Minnesota
  
• hyb_gga_xc_b97_1p:
  version of B97 by Cohen and Handy
  
• hyb_gga_xc_pbe_mol0:
  PBEmol0
  
• hyb_gga_xc_pbe_sol0:
  PBEsol0
  
• hyb_gga_xc_pbeb0:
  PBEbeta0
  
• hyb_gga_xc_pbe_molb0:
  PBEmolbeta0
  
• hyb_gga_xc_pbe50:
  PBE0 with 50% exx
  
• hyb_gga_xc_b3pw91:
  The original (ACM) hybrid of Becke
  
• hyb_gga_xc_b3lyp:
  The (in)famous B3LYP
  
• hyb_gga_xc_b3p86:
  Perdew 86 hybrid similar to B3PW91
  
• hyb_gga_xc_o3lyp:
  hybrid using the optx functional
  
• hyb_gga_xc_mpw1k:
  mixture of mPW91 and PW91 optimized for kinetics
  
• hyb_gga_xc_pbeh:
  aka PBE0 or PBE1PBE
  
• hyb_gga_xc_b97:
  Becke 97
  
• hyb_gga_xc_b97_1:
  Becke 97-1
  
• hyb_gga_xc_b97_2:
  Becke 97-2
  
• hyb_gga_xc_x3lyp:
  hybrid by Xu and Goddard
  
• hyb_gga_xc_b1wc:
  Becke 1-parameter mixture of WC and PBE
  
• hyb_gga_xc_b97_k:
  Boese-Martin for Kinetics
  
• hyb_gga_xc_b97_3:
  Becke 97-3
  
• hyb_gga_xc_mpw3pw:
  mixture with the mPW functional
  
• hyb_gga_xc_b1lyp:
  Becke 1-parameter mixture of B88 and LYP
  
• hyb_gga_xc_b1pw91:
  Becke 1-parameter mixture of B88 and PW91
  
• hyb_gga_xc_mpw1pw:
  Becke 1-parameter mixture of mPW91 and PW91
  
• hyb_gga_xc_mpw3lyp:
  mixture of mPW and LYP
  
• hyb_gga_xc_sb98_1a:
  Schmider-Becke 98 parameterization 1a
  
• hyb_gga_xc_sb98_1b:
  Schmider-Becke 98 parameterization 1b
  
• hyb_gga_xc_sb98_1c:
  Schmider-Becke 98 parameterization 1c
  
• hyb_gga_xc_sb98_2a:
  Schmider-Becke 98 parameterization 2a
  
• hyb_gga_xc_sb98_2b:
  Schmider-Becke 98 parameterization 2b
  
• hyb_gga_xc_sb98_2c:
  Schmider-Becke 98 parameterization 2c
  
• hyb_gga_x_sogga11_x:
  Hybrid based on SOGGA11 form
  
• hyb_gga_xc_hse03:
  the 2003 version of the screened hybrid HSE
  
• hyb_gga_xc_hse06:
  the 2006 version of the screened hybrid HSE
  
• hyb_gga_xc_hjs_pbe:
  HJS hybrid screened exchange PBE version
  
• hyb_gga_xc_hjs_pbe_sol:
  HJS hybrid screened exchange PBE_SOL version
  
• hyb_gga_xc_hjs_b88:
  HJS hybrid screened exchange B88 version
  
• hyb_gga_xc_hjs_b97x:
  HJS hybrid screened exchange B97x version
  
• hyb_gga_xc_cam_b3lyp:
  CAM version of B3LYP
  
• hyb_gga_xc_tuned_cam_b3lyp:
  CAM version of B3LYP tuned for excitations
  
• hyb_gga_xc_bhandh:
  Becke half-and-half
  
• hyb_gga_xc_bhandhlyp:
  Becke half-and-half with B88 exchange
  
• hyb_gga_xc_mb3lyp_rc04:
  B3LYP with RC04 LDA
  
• hyb_gga_xc_mpwlyp1m:
  MPW with 1 par. for metals/LYP
  
• hyb_gga_xc_revb3lyp:
  Revised B3LYP
  
• hyb_gga_xc_camy_blyp:
  BLYP with yukawa screening
  
• hyb_gga_xc_pbe0_13:
  PBE0-1/3
  
• hyb_gga_xc_b3lyps:
  B3LYP* functional
  
• hyb_gga_xc_wb97:
  Chai and Head-Gordon
  
• hyb_gga_xc_wb97x:
  Chai and Head-Gordon
  
• hyb_gga_xc_lrc_wpbeh:
  Long-range corrected functional by Rorhdanz et al
  
• hyb_gga_xc_wb97x_v:
  Mardirossian and Head-Gordon
  
• hyb_gga_xc_lcy_pbe:
  PBE with yukawa screening
  
• hyb_gga_xc_lcy_blyp:
  BLYP with yukawa screening
  
• hyb_gga_xc_lc_vv10:
  Vydrov and Van Voorhis
  
• hyb_gga_xc_camy_b3lyp:
  B3LYP with Yukawa screening
  
• hyb_gga_xc_wb97x_d:
  Chai and Head-Gordon
  
• hyb_gga_xc_hpbeint:
  hPBEint
  
• hyb_gga_xc_lrc_wpbe:
  Long-range corrected functional by Rorhdanz et al
  
• hyb_gga_xc_b3lyp5:
  B3LYP with VWN functional 5 instead of RPA
  
• hyb_gga_xc_edf2:
  Empirical functional from Lin, George and Gill
  
• hyb_gga_xc_cap0:
  Correct Asymptotic Potential hybrid
  
• hyb_gga_xc_lc_wpbe:
  Long-range corrected functional by Vydrov and Scuseria
  
• hyb_gga_xc_hse12:
  HSE12 by Moussa, Schultz and Chelikowsky
  
• hyb_gga_xc_hse12s:
  Short-range HSE12 by Moussa, Schultz, and Chelikowsky
  
• hyb_gga_xc_hse_sol:
  HSEsol functional by Schimka, Harl, and Kresse
  
• hyb_gga_xc_cam_qtp_01:
  CAM-QTP(01): CAM-B3LYP retuned using ionization potentials of water
  
• hyb_gga_xc_mpw1lyp:
  Becke 1-parameter mixture of mPW91 and LYP
  
• hyb_gga_xc_mpw1pbe:
  Becke 1-parameter mixture of mPW91 and PBE
  
• hyb_gga_xc_kmlyp:
  Kang-Musgrave hybrid
  
• hyb_gga_xc_b5050lyp:
  Like B3LYP but more exact exchange
  
• mgga_c_dldf:
  Dispersionless Density Functional
  
• mgga_xc_zlp:
  Zhao, Levy & Parr, Eq. (21)
  
• mgga_xc_otpss_d:
  oTPSS_D functional of Goerigk and Grimme
  
• mgga_c_cs:
  Colle and Salvetti
  
• mgga_c_mn12_sx:
  MN12-SX correlation functional from Minnesota
  
• mgga_c_mn12_l:
  MN12-L correlation functional from Minnesota
  
• mgga_c_m11_l:
  M11-L correlation functional from Minnesota
  
• mgga_c_m11:
  M11 correlation functional from Minnesota
  
• mgga_c_m08_so:
  M08-SO correlation functional from Minnesota
  
• mgga_c_m08_hx:
  M08-HX correlation functional from Minnesota
  
• mgga_x_lta:
  Local tau approximation of Ernzerhof & Scuseria
  
• mgga_x_tpss:
  Tao, Perdew, Staroverov & Scuseria exchange
  
• mgga_x_m06_l:
  M06-L exchange functional from Minnesota
  
• mgga_x_gvt4:
  GVT4 from Van Voorhis and Scuseria
  
• mgga_x_tau_hcth:
  tau-HCTH from Boese and Handy
  
• mgga_x_br89:
  Becke-Roussel 89
  
• mgga_x_bj06:
  Becke & Johnson correction to Becke-Roussel 89
  
• mgga_x_tb09:
  Tran & Blaha correction to Becke & Johnson
  
• mgga_x_rpp09:
  Rasanen, Pittalis, and Proetto correction to Becke & Johnson
  
• mgga_x_2d_prhg07:
  Pittalis, Rasanen, Helbig, Gross Exchange Functional
  
• mgga_x_2d_prhg07_prp10:
  PRGH07 with PRP10 correction
  
• mgga_x_revtpss:
  revised Tao, Perdew, Staroverov & Scuseria exchange
  
• mgga_x_pkzb:
  Perdew, Kurth, Zupan, and Blaha
  
• mgga_x_ms0:
  MS exchange of Sun, Xiao, and Ruzsinszky
  
• mgga_x_ms1:
  MS1 exchange of Sun, et al
  
• mgga_x_ms2:
  MS2 exchange of Sun, et al
  
• mgga_x_m11_l:
  M11-L exchange functional from Minnesota
  
• mgga_x_mn12_l:
  MN12-L exchange functional from Minnesota
  
• mgga_xc_cc06:
  Cancio and Chou 2006
  
• mgga_x_mk00:
  Exchange for accurate virtual orbital energies
  
• mgga_c_tpss:
  Tao, Perdew, Staroverov & Scuseria correlation
  
• mgga_c_vsxc:
  VSxc from Van Voorhis and Scuseria (correlation part)
  
• mgga_c_m06_l:
  M06-L correlation functional from Minnesota
  
• mgga_c_m06_hf:
  M06-HF correlation functional from Minnesota
  
• mgga_c_m06:
  M06 correlation functional from Minnesota
  
• mgga_c_m06_2x:
  M06-2X correlation functional from Minnesota
  
• mgga_c_m05:
  M05 correlation functional from Minnesota
  
• mgga_c_m05_2x:
  M05-2X correlation functional from Minnesota
  
• mgga_c_pkzb:
  Perdew, Kurth, Zupan, and Blaha
  
• mgga_c_bc95:
  Becke correlation 95
  
• mgga_c_revtpss:
  revised TPSS correlation
  
• mgga_xc_tpsslyp1w:
  Functionals fitted for water
  
• mgga_x_mk00b:
  Exchange for accurate virtual orbital energies (v. B)
  
• mgga_x_bloc:
  functional with balanced localization
  
• mgga_x_modtpss:
  Modified Tao, Perdew, Staroverov & Scuseria exchange
  
• mgga_c_tpssloc:
  Semilocal dynamical correlation
  
• mgga_x_mbeef:
  mBEEF exchange
  
• mgga_x_mbeefvdw:
  mBEEF-vdW exchange
  
• mgga_xc_b97m_v:
  Mardirossian and Head-Gordon
  
• mgga_x_mvs:
  MVS exchange of Sun, Perdew, and Ruzsinszky
  
• mgga_x_mn15_l:
  MN15-L exhange functional from Minnesota
  
• mgga_c_mn15_l:
  MN15-L correlation functional from Minnesota
  
• mgga_x_scan:
  SCAN exchange of Sun, Ruzsinszky, and Perdew
  
• mgga_c_scan:
  SCAN correlation
  
• mgga_c_mn15:
  MN15 correlation functional from Minnesota
  
• mgga_x_b00:
  Becke 2000
  
• mgga_xc_hle17:
  high local exchange 2017
  
• mgga_c_scan_rvv10:
  SCAN correlation + rVV10 correlation
  
• mgga_x_revm06_l:
  revised M06-L exchange functional from Minnesota
  
• mgga_c_revm06_l:
  Revised M06-L correlation functional from Minnesota
  
• mgga_x_tm:
  Tao and Mo 2016
  
• mgga_x_vt84:
  meta-GGA version of VT{8,4} GGA
  
• mgga_x_sa_tpss:
  TPSS with correct surface asymptotics
  
• mgga_c_kcis:
  Krieger, Chen, Iafrate, and Savin
  
• mgga_xc_lp90:
  Lee & Parr, Eq. (56)
  
• mgga_c_b88:
  Meta-GGA correlation by Becke
  
• mgga_x_gx:
  GX functional of Loos
  
• mgga_x_pbe_gx:
  PBE-GX functional of Loos
  
• mgga_x_revscan:
  revised SCAN
  
• mgga_c_revscan:
  revised SCAN correlation
  
• mgga_c_scan_vv10:
  SCAN correlation + VV10 correlation
  
• mgga_c_revscan_vv10:
  revised SCAN correlation
  
• mgga_x_br89_explicit:
  Becke-Roussel 89 with an explicit inversion of x(y)
  
• hyb_mgga_x_dldf:
  Dispersionless Density Functional
  
• hyb_mgga_x_ms2h:
  MS2 hybrid exchange of Sun, et al
  
• hyb_mgga_x_mn12_sx:
  MN12-SX hybrid exchange functional from Minnesota
  
• hyb_mgga_x_scan0:
  SCAN hybrid exchange
  
• hyb_mgga_x_mn15:
  MN15 hybrid exchange functional from Minnesota
  
• hyb_mgga_x_bmk:
  Boese-Martin for kinetics
  
• hyb_mgga_x_tau_hcth:
  Hybrid version of tau-HCTH
  
• hyb_mgga_x_m08_hx:
  M08-HX exchange functional from Minnesota
  
• hyb_mgga_x_m08_so:
  M08-SO exchange functional from Minnesota
  
• hyb_mgga_x_m11:
  M11 hybrid exchange functional from Minnesota
  
• hyb_mgga_x_m05:
  M05 hybrid exchange functional from Minnesota
  
• hyb_mgga_x_m05_2x:
  M05-2X hybrid exchange functional from Minnesota
  
• hyb_mgga_xc_b88b95:
  Mixture of B88 with BC95 (B1B95)
  
• hyb_mgga_xc_b86b95:
  Mixture of B86 with BC95
  
• hyb_mgga_xc_pw86b95:
  Mixture of PW86 with BC95
  
• hyb_mgga_xc_bb1k:
  Mixture of B88 with BC95 from Zhao and Truhlar
  
• hyb_mgga_x_m06_hf:
  M06-HF hybrid exchange functional from Minnesota
  
• hyb_mgga_xc_mpw1b95:
  Mixture of mPW91 with BC95 from Zhao and Truhlar
  
• hyb_mgga_xc_mpwb1k:
  Mixture of mPW91 with BC95 for kinetics
  
• hyb_mgga_xc_x1b95:
  Mixture of X with BC95
  
• hyb_mgga_xc_xb1k:
  Mixture of X with BC95 for kinetics
  
• hyb_mgga_x_m06:
  M06 hybrid exchange functional from Minnesota
  
• hyb_mgga_x_m06_2x:
  M06-2X hybrid exchange functional from Minnesota
  
• hyb_mgga_xc_pw6b95:
  Mixture of PW91 with BC95 from Zhao and Truhlar
  
• hyb_mgga_xc_pwb6k:
  Mixture of PW91 with BC95 from Zhao and Truhlar for kinetics
  
• hyb_mgga_xc_tpssh:
  TPSS hybrid
  
• hyb_mgga_xc_revtpssh:
  revTPSS hybrid
  
• hyb_mgga_x_mvsh:
  MVSh hybrid
  
• hyb_mgga_xc_wb97m_v:
  Mardirossian and Head-Gordon
  
• hyb_mgga_xc_b0kcis:
  Hybrid based on KCIS
  
• hyb_mgga_xc_mpw1kcis:
  Modified Perdew-Wang + KCIS hybrid
  
• hyb_mgga_xc_mpwkcis1k:
  Modified Perdew-Wang + KCIS hybrid with more exact exchange
  
• hyb_mgga_xc_pbe1kcis:
  Perdew-Burke-Ernzerhof + KCIS hybrid
  
• hyb_mgga_xc_tpss1kcis:
  TPSS hybrid with KCIS correlation
  
• hyb_mgga_x_revscan0:
  revised SCAN hybrid exchange
  
• hyb_mgga_xc_b98:
  Becke 98
  
• oep_x:
  OEP: Exact exchange (not from libxc).
  
• slater_x:
  Slater approximation to the exact exchange (not from libxc).
  
• fbe_x:
  Exchange functional based on the force balance equation (not from libxc).
  
• ks_inversion:
  Inversion of KS potential (not from libxc).
  
• lda_xc_cmplx:
  Complex-scaled LDA exchange and correlation (not from libxc).
  
• pbe_xc_cmplx:
  Complex-scaled PBE exchange and correlation (not from libxc).
  
• lb94_xc_cmplx:
  Complex-scaled LB94 exchange and correlation (not from libxc).
  
• rdmft_xc_m:
  RDMFT Mueller functional (not from libxc).
  
• xc_half_hartree:
  Half-Hartree exchange for two electrons (supports complex scaling) (not from libxc). Defined by $v_{xc}(r) = v_H(r) / 2$.
  
• hyb_gga_xc_mvorb_hse06:
  Density-based mixing parameter of HSE06 (not from libxc).
  
• hyb_gga_xc_mvorb_pbeh:
  Density-based mixing parameter of PBEH (not from libxc). At the moment this is not supported for libxc >= 4.0.
  
• vdw_c_vdwdf:
  van der Waals density functional vdW-DF correlation from libvdwxc (not from libxc). Use with gga_x_pbe_r.
  
• vdw_c_vdwdf2:
  van der Waals density functional vdW-DF2 correlation from libvdwxc (not from libxc). Use with gga_x_rpw86.
  
• vdw_c_vdwdfcx:
  van der Waals density functional vdW-DF-cx correlation from libvdwxc (not from libxc). Use with gga_x_lv_rpw86.
  
• none:
  Exchange and correlation set to zero (not from libxc).
  

Name XCKernel
Section Hamiltonian::XC
Type integer

Defines the exchange-correlation kernel. Only LDA kernels are available currently. The options are the same as XCFunctional. Note: the kernel is only needed for Casida, Sternheimer, or optimal-control calculations. Defaults:
1D: lda_x_1d + lda_c_1d_csc
2D: lda_x_2d + lda_c_2d_amgb
3D: lda_x + lda_c_pz_mod

Options:

• xc_functional:
  The same functional defined by XCFunctional.
  

Name XCKernelLRCAlpha
Section Hamiltonian::XC
Type float
Default 0.0

Set to a non-zero value to add a long-range correction for solids to the kernel. This is the $\alpha$ parameter defined in S. Botti et al., Phys. Rev. B 69, 155112 (2004). The $\Gamma = \Gamma = 0$ term $-\alpha/q^2$ is taken into account by introducing an additional pole to the polarizability (see R. Stubner <i>et al.</i>, <i>Phys. Rev. B</i> 70, 245119 (2004)). The rest of the terms are included by multiplying the Hartree term by $1 - \alpha / 4 \pi$. The use of non-zero $\alpha$ in combination with <tt>HamiltonianVariation</tt> = <tt>V_ext_only</tt> corresponds to account of only the $\Gamma = \Gamma = 0$ term. Applicable only to isotropic systems. (Experimental)

Name XCUseGaugeIndependentKED
Section Hamiltonian::XC
Type logical
Default yes

If true, when evaluating the XC functional, a term including the (paramagnetic or total) current is added to the kinetic-energy density such as to make it gauge-independent. Applies only to meta-GGA (and hybrid meta-GGA) functionals.

Name Xlength
Section Mesh::Simulation Box
Type float
Default Radius

If BoxShape is cylinder, the total length of the cylinder is twice Xlength. Note that when PeriodicDimensions = 1, then the length of the cylinder is determined from the lattice vectors.

Name XSFCoordinates
Section System::Coordinates
Type string

Another option besides PDB and XYZ coordinates formats is XSF, as defined by the XCrySDen visualization program. Specify the filename with this variable. The lattice vectors will also be read from this file and the value of PeriodicDimensions needs to be compatible with the first line (CRYSTAL, SLAB, POLYMER, or MOLECULE). The file should not contain ATOMS, CONVVEC, or PRIMCOORD. NOTE: The coordinates are treated in the units specified by Units and/or UnitsInput.

Name XSFCoordinatesAnimStep
Section System::Coordinates
Type integer
Default 1

If an animated file is given with XSFCoordinates, this variable selects which animation step will be used. The PRIMVEC block must be written for each step.

Name XSFGOConstrains
Section Calculation Modes::Geometry Optimization
Type string

Like XYZGOConstrains but in XCrySDen format, as in XSFCoordinates.

Name XSFVelocities
Section System::Velocities
Type string

Like XYZVelocities but in XCrySDen format, as in XSFCoordinates.

Name XYZCoordinates
Section System::Coordinates
Type string

If PDBCoordinates is not present, the program reads the atomic coordinates from the XYZ file specified by the variable XYZCoordinates – in case this variable is present. The XYZ format is very simple: The first line of the file has an integer indicating the number of atoms. The second can contain comments that are simply ignored by Octopus. Then there follows one line per atom, containing the chemical species and the Cartesian coordinates of the atom.

WARNING: By default the coordinates are treated in the units specified by Units and/or UnitsInput, which means Octopus might expect xyz files to be in atomic units. If you want the XYZ file to be read in Angstrom, as most codes do, you can set the variable UnitsXYZFiles to angstrom.

Name XYZGOConstrains
Section Calculation Modes::Geometry Optimization
Type string

Octopus will try to read the coordinate-dependent constrains from the XYZ file specified by the variable XYZGOConstrains. Note: It is important for the contrains to maintain the ordering in which the atoms were defined in the coordinates specifications. Moreover, constrains impose fixed absolute coordinates, therefore constrains are not compatible with GOCenter = yes

Name XYZVelocities
Section System::Velocities
Type string

Octopus will try to read the starting velocities of the atoms from the XYZ file specified by the variable XYZVelocities. Note that you do not need to specify initial velocities if you are not going to perform ion dynamics; if you are going to allow the ions to move but the velocities are not specified, they are considered to be null. Note: It is important for the velocities to maintain the ordering in which the atoms were defined in the coordinates specifications.