GEO_OPT
This section sets the environment of the geometry optimizer. [Edit on GitHub]
Subsections
Keywords
Keyword descriptions
- EPS_SYMMETRY
Type: real
Default: 1.00000000E-004
Usage: EPS_SYMMETRY {REAL}Description: Accuracy for space group determination. EPS_SYMMETRY is dimensionless. Roughly speaking, two scaled (fractional) atomic positions v1, v2 are considered identical if |v1 - v2| < EPS_SYMMETRY.
- KEEP_SPACE_GROUP
Type: logical
Default: F
Lone keyword: T
Usage: KEEP_SPACE_GROUP .TRUE.Description: Detect space group of the system and preserve it during optimization. The space group symmetry is applied to coordinates, forces, the stress tensor, and the CELL_OPT cell metric. It works for supercell. It does not affect/reduce computational cost. Use EPS_SYMMETRY to adjust the detection threshold.
Mentions: ⭐K-Points, ⭐Geometry and cell optimization
- MAX_DR
Type: real
Default: 3.00000000E-003 [bohr]
Usage: MAX_DR {real}Description: Convergence criterion for the maximum geometry change between the current and the last optimizer iteration.
- MAX_FORCE
Type: real
Default: 4.50000000E-004 [bohr^-1*hartree]
Usage: MAX_FORCE {real}Description: Convergence criterion for the maximum force component of the current configuration.
Mentions: ⭐Geometry and cell optimization, ⭐Simulating Vibronic Effects in Optical Spectra
- MAX_ITER
Type: integer
Default: 200
Usage: MAX_ITER {integer}Description: Specifies the maximum number of geometry optimization steps. One step might imply several force evaluations for the CG and LBFGS optimizers.
Mentions: ⭐Geometry and cell optimization
- OPTIMIZER
Type: enum
Default: BFGS
Aliases: MINIMIZER
Usage: OPTIMIZER {BFGS|LBFGS|CG}Description: Specify which method to use to perform a geometry optimization.
Valid values:
BFGSMost efficient minimizer, but only for ‘small’ systems, as it relies on diagonalization of a full Hessian matrixLBFGSLimited-memory variant of BFGS suitable for large systems. Not as well fine-tuned but can be more robust.CGconjugate gradients, robust minimizer (depending on the line search) also OK for large systems
References: Byrd1995
Mentions: ⭐Geometry and cell optimization
- RMS_DR
Type: real
Default: 1.50000000E-003 [bohr]
Usage: RMS_DR {real}Description: Convergence criterion for the root mean square (RMS) geometry change between the current and the last optimizer iteration.
Mentions: ⭐Geometry and cell optimization
- RMS_FORCE
Type: real
Default: 3.00000000E-004 [bohr^-1*hartree]
Usage: RMS_FORCE {real}Description: Convergence criterion for the root mean square (RMS) force of the current configuration.
- SHOW_SPACE_GROUP
Type: logical
Default: F
Lone keyword: T
Usage: SHOW_SPACE_GROUP .TRUE.Description: Detect and show space group of the system after optimization. It works for supercell. It does not affect/reduce computational cost. Use EPS_SYMMETRY to adjust the detection threshold.
- SPGR_PRINT_ATOMS
Type: logical
Default: F
Lone keyword: TDescription: Print equivalent atoms list for each space group symmetry operation.
- STEP_START_VAL
Type: integer
Default: 0
Usage: step_start_valDescription: The starting step value for the GEO_OPT module.
- SYMM_EXCLUDE_RANGE
Type: integer[2]
Repeatable: yes
Usage: SYMM_EXCLUDE_RANGE {Int} {Int}Description: Range of atoms to exclude from space group symmetry. These atoms are excluded from both identification and enforcement. This keyword can be repeated.
- SYMM_REDUCTION
Type: real[3]
Default: 0.00000000E+000 0.00000000E+000 0.00000000E+000
Usage: SYMM_REDUCTION 0.0 0.0 0.0Description: Direction of the external static electric field. Some symmetry operations are not compatible with the direction of an electric field. These operations are used when enforcing the space group.
- TYPE
Type: enum
Default: MINIMIZATION
Usage: TYPE (MINIMIZATION|TRANSITION_STATE)Description: Specify which kind of geometry optimization to perform
Valid values:
MINIMIZATIONPerforms a geometry minimization.TRANSITION_STATEPerforms a transition state optimization.
Mentions: ⭐Geometry and cell optimization