Back to the main page of this manual  Input reference of CP2K version 9.1 
CP2K_INPUT /
MOTION /
SHELL_OPT
EPS_SYMMETRY {Real} 

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.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
1.00000000E004 
KEEP_SPACE_GROUP {Logical} 

Detect space group of the system and preserve it during optimization. The space group symmetry is applied to coordinates, forces, and the stress tensor. It works for supercell. It does not affect/reduce computational cost. Use EPS_SYMMETRY to adjust the detection threshold.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
MAX_DR {Real} 

Convergence criterion for the maximum geometry change between the current and the last optimizer iteration.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
3.00000000E003 

Default unit:
[bohr]

MAX_FORCE {Real} 

Convergence criterion for the maximum force component of the current configuration.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
4.50000000E004 

Default unit:
[bohr^1*hartree]

MAX_ITER {Integer} 

Specifies the maximum number of geometry optimization steps. One step might imply several force evaluations for the CG and LBFGS optimizers.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
200 
OPTIMIZER {Keyword} 

Specify which method to use to perform a geometry optimization.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
BFGS 

List of valid keywords:


Alias names for this keyword: MINIMIZER  
This keyword cites the following reference: [BYRD1995] 
RMS_DR {Real} 

Convergence criterion for the root mean square (RMS) geometry change between the current and the last optimizer iteration.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
1.50000000E003 

Default unit:
[bohr]

RMS_FORCE {Real} 

Convergence criterion for the root mean square (RMS) force of the current configuration.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
3.00000000E004 

Default unit:
[bohr^1*hartree]

SPGR_PRINT_ATOMS {Logical} 

Print equivalent atoms list for each space group symmetry operation.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
STEP_START_VAL {Integer} 

The starting step value for the SHELL_OPT module.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
0 
SYMM_EXCLUDE_RANGE {Integer} {Integer} 

Range of atoms to exclude from space group symmetry. These atoms are excluded from both identification and enforcement. This keyword can be repeated.  
This keyword can be repeated and it expects precisely 2 integers. 
SYMM_REDUCTION {Real} {Real} {Real} 

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.  
This keyword cannot be repeated and it expects precisely 3 reals.  
Default values:
0.00000000E+000 0.00000000E+000 0.00000000E+000 
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