XAS

References: Iannuzzi2007

Sets the method of choice to calculate core-level excitation spectra. The occupied states from which we calculate the excitation should be specified. Localization of the orbitals may be useful. [Edit on GitHub]

Subsections

Keyword descriptions

SECTION_PARAMETERS: logical = F 

Lone keyword: T

Usage: &XAS T

controls the activation of core-level spectroscopy simulations [Edit on GitHub]

ADDED_MOS: integer = -1 

Usage: ADDED_MOS {integer}

Number of additional MOS added spin up only [Edit on GitHub]

ATOMS_LIST: integer

Keyword can be repeated.

Aliases: AT_LIST

Usage: ATOMS_LIST {integer} {integer} .. {integer}

Indexes of the atoms to be excited. This keyword can be repeated several times (useful if you have to specify many indexes). [Edit on GitHub]

DIPOLE_FORM: enum = VELOCITY 

Aliases: DIP_FORM

Usage: DIPOLE_FORM string

Valid values:

LENGTH Length form ⟨ i | e r | j ⟩
VELOCITY Velocity form ⟨ i | d/dr | j ⟩

Type of integral to get the oscillator strengths in the diipole approximation [Edit on GitHub]

EPS_ADDED: real = 1.00000000E-005 

Usage: EPS_ADDED 1.e-6

target accuracy incalculation of the added orbitals [Edit on GitHub]

MAX_ITER_ADDED: integer = 2999 

Usage: MAX_ITER_ADDED 100

maximum number of iteration in calculation of added orbitals [Edit on GitHub]

METHOD: enum = NONE 

Aliases: XAS_METHOD

Usage: METHOD TP_HH

Valid values:

NONE No core electron spectroscopy
TP_HH Transition potential half-hole
TP_FH Transition potential full-hole
TP_VAL Hole in homo for X-ray emission only
TP_XHH Transition potential excited half-hole
TP_XFH Transition potential excited full-hole
DSCF DSCF calculations to compute the first (core)excited state
TP_FLEX Transition potential with generalized core occupation and total number of electrons

Method to be used to calculate core-level excitation spectra [Edit on GitHub]

NGAUSS: integer = 3 

Usage: NGAUSS {integer}

Number of gto’s for the expansion of the STO of the type given by STATE_TYPE [Edit on GitHub]

ORBITAL_LIST: integer

Keyword can be repeated.

Aliases: ORBITAL_LIST

Usage: ORBITAL_LIST {integer} {integer} .. {integer}

Indices of the localized orbitals to be excited. This keyword can be repeated several times (useful if you have to specify many indexes). [Edit on GitHub]

OVERLAP_THRESHOLD: real = 1.00000000E+000 

Usage: OVERLAP_THRESHOLD 8.e-1

Threshold for including more than one initial core excited state per atom. The threshold is taken relative to the maximum overlap. [Edit on GitHub]

RESTART: logical = F 

Lone keyword: T

Usage: RESTART

Restart the excited state if the restart file exists [Edit on GitHub]

SPIN_CHANNEL: integer = 1 

Usage: SPIN_CHANNEL 1

# Spin channel of the excited orbital [Edit on GitHub]

STATE_SEARCH: integer = -1 

Usage: STATE_SEARCH 1

# of states where to look for the one to be excited [Edit on GitHub]

STATE_TYPE: enum = 1S 

Aliases: TYPE

Usage: STATE_TYPE 1S

Valid values:

1S 1s orbitals
2S 2s orbitals
2P 2p orbitals
3S 3s orbitals
3P 3p orbitals
3D 3d orbitals
4S 4s orbitals
4P 4p orbitals
4D 4d orbitals
4F 4f orbitals

Type of the orbitals that are excited for the xas spectra calculation [Edit on GitHub]

WFN_RESTART_FILE_NAME: string

Aliases: RESTART_FILE_NAME

Usage: WFN_RESTART_FILE_NAME

Root of the file names where to read the MOS from which to restart the calculation of the core level excited states [Edit on GitHub]

XAS_CORE: real = 5.00000000E-001 

Usage: XAS_CORE 0.5

Occupation of the core state in XAS calculation by TP_FLEX. [Edit on GitHub]

XAS_TOT_EL: real = -1.00000000E+000 

Usage: XAS_TOT_EL 10

Total number of electrons for spin channel alpha, in XAS calculation by TP_FLEX. If it is a negative value, the number of electrons is set to GS number of electrons minus the amount subtracted from the core state [Edit on GitHub]

XES_CORE: real = 1.00000000E+000 

Usage: XES_CORE 0.5

Occupation of the core state in XES calculation by TP_VAL. The HOMO is emptied by the same amount. [Edit on GitHub]

XES_EMPTY_HOMO: logical = F 

Lone keyword: T

Usage: XES_EMPTY_HOMO

Set the occupation of the HOMO in XES calculation by TP_VAL. The HOMO can be emptied or not, if the core is still full. [Edit on GitHub]

XAS

Keywords

Keyword descriptions