XAS
References: Iannuzzi2007
Controls transition-potential and delta-SCF calculations of core-level excitation spectra. The occupied states from which the excitations are calculated should be specified. Localization of the orbitals may be useful. [Edit on GitHub]
Keywords
Keyword descriptions
- SECTION_PARAMETERS
Type: logical
Default: F
Lone keyword: T
Usage: &XAS TDescription: controls the activation of core-level spectroscopy simulations
- ADDED_MOS
Type: integer
Default: -1
Usage: ADDED_MOS {integer}Description: Number of additional MOS added spin up only
- ATOMS_LIST
Type: integer[ ]
Repeatable: yes
Aliases: AT_LIST
Usage: ATOMS_LIST {integer} {integer} .. {integer}Description: Indexes of the atoms to be excited. This keyword can be repeated several times (useful if you have to specify many indexes).
- DIPOLE_FORM
Type: enum
Default: VELOCITY
Aliases: DIP_FORM
Usage: DIPOLE_FORM stringDescription: Type of integral to get the oscillator strengths in the diipole approximation
Valid values:
LENGTHLength form ⟨ i | e r | j ⟩VELOCITYVelocity form ⟨ i | d/dr | j ⟩
- EPS_ADDED
Type: real
Default: 1.00000000E-005
Usage: EPS_ADDED 1.e-6Description: target accuracy incalculation of the added orbitals
- MAX_ITER_ADDED
Type: integer
Default: 2999
Usage: MAX_ITER_ADDED 100Description: maximum number of iteration in calculation of added orbitals
- METHOD
Type: enum
Default: NONE
Aliases: XAS_METHOD
Usage: METHOD TP_HHDescription: Method to be used to calculate core-level excitation spectra
Valid values:
NONENo core electron spectroscopyTP_HHTransition potential half-holeTP_FHTransition potential full-holeTP_VALHole in homo for X-ray emission onlyTP_XHHTransition potential excited half-holeTP_XFHTransition potential excited full-holeDSCFDSCF calculations to compute the first (core)excited stateTP_FLEXTransition potential with generalized core occupation and total number of electrons
- NGAUSS
Type: integer
Default: 3
Usage: NGAUSS {integer}Description: Number of gto’s for the expansion of the STO of the type given by STATE_TYPE
- ORBITAL_LIST
Type: integer[ ]
Repeatable: yes
Aliases: ORBITAL_LIST
Usage: ORBITAL_LIST {integer} {integer} .. {integer}Description: Indices of the localized orbitals to be excited. This keyword can be repeated several times (useful if you have to specify many indexes).
- OVERLAP_THRESHOLD
Type: real
Default: 1.00000000E+000
Usage: OVERLAP_THRESHOLD 8.e-1Description: Threshold for including more than one initial core excited state per atom. The threshold is taken relative to the maximum overlap.
- RESTART
Type: logical
Default: F
Lone keyword: T
Usage: RESTARTDescription: Restart the excited state if the restart file exists
- SPIN_CHANNEL
Type: integer
Default: 1
Usage: SPIN_CHANNEL 1Description: # Spin channel of the excited orbital
- STATE_SEARCH
Type: integer
Default: -1
Usage: STATE_SEARCH 1Description: # of states where to look for the one to be excited
- STATE_TYPE
Type: enum
Default: 1S
Aliases: TYPE
Usage: STATE_TYPE 1SDescription: Type of the orbitals that are excited for the xas spectra calculation
Valid values:
1S1s orbitals2S2s orbitals2P2p orbitals3S3s orbitals3P3p orbitals3D3d orbitals4S4s orbitals4P4p orbitals4D4d orbitals4F4f orbitals
- WFN_RESTART_FILE_NAME
Type: string
Aliases: RESTART_FILE_NAME
Usage: WFN_RESTART_FILE_NAMEDescription: Root of the file names where to read the MOS from which to restart the calculation of the core level excited states
- XAS_CORE
Type: real
Default: 5.00000000E-001
Usage: XAS_CORE 0.5Description: Occupation of the core state in XAS calculation by TP_FLEX.
- XAS_TOT_EL
Type: real
Default: -1.00000000E+000
Usage: XAS_TOT_EL 10Description: 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
- XES_CORE
Type: real
Default: 1.00000000E+000
Usage: XES_CORE 0.5Description: Occupation of the core state in XES calculation by TP_VAL. The HOMO is emptied by the same amount.
- XES_EMPTY_HOMO
Type: logical
Default: F
Lone keyword: T
Usage: XES_EMPTY_HOMODescription: 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.