Back to the main page of this manual  Input reference of CP2K version 2023.1 
CP2K_INPUT /
FORCE_EVAL /
DFT /
ENERGY_CORRECTION /
RESPONSE_SOLVER
EPS {Real} 

Target accuracy for the convergence of the conjugate gradient.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
1.00000000E012 
EPS_FILTER {Real} 

Threshold used for filtering matrix operations.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
1.00000000E010 
EPS_LANCZOS {Real} 

Threshold used for lanczos estimates.  
This keyword cannot be repeated and it expects precisely one real.  
Default value:
1.00000000E003 
MATRIX_CLUSTER_TYPE {Keyword} 

Specify how atomic blocks should be clustered in the used matrices, in order to improve flop rate, and possibly speedup the matrix multiply. Note that the atomic s_preconditioner can not be used.Furthermore, since screening is on matrix blocks, slightly more accurate results can be expected with molecular.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
ATOMIC 

List of valid keywords:

MAX_ITER {Integer} 

Maximum number of conjugate gradient iterationto be performed for one optimization.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
50 
MAX_ITER_LANCZOS {Integer} 

Maximum number of lanczos iterations.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
128 
METHOD {Keyword} 

Algorithm used to solve response equation.Both solver are conjugate gradient based, but use either a vector (MOcoefficient)or density matrix formalism in the orthonormal AObasis to obtain response density  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
AO_ORTHO 

List of valid keywords:

PRECONDITIONER {Keyword} 

Type of preconditioner to be used with MO conjugate gradient solver. They differ in effectiveness, cost of construction, cost of application. Properly preconditioned minimization can be orders of magnitude faster than doing nothing.Only multilevel conjugate gradient preconditioner (MULTI_LEVEL) available for AO response solver (AO_ORTHO).  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
MULTI_LEVEL 

List of valid keywords:

RESTART {Logical} 

Restart the response calculation if the restart file exists  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
RESTART_EVERY {Integer} 

Restart the conjugate gradient after the specified number of iterations.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
50 
SINGLE_PRECISION_MATRICES {Logical} 

Matrices used within the LS code can be either double or single precision.  
This keyword cannot be repeated and it expects precisely one logical.  
The lone keyword behaves as a switch to
.TRUE. 

Default value:
.FALSE. 
S_INVERSION {Keyword} 

Method used to compute the inverse of S.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
SIGN_SQRT 

List of valid keywords:

S_PRECONDITIONER {Keyword} 

Preconditions S with some appropriate form.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
ATOMIC 

List of valid keywords:

S_SQRT_METHOD {Keyword} 

Method for the caclulation of the sqrt of S.  
This keyword cannot be repeated and it expects precisely one keyword.  
Default value:
NEWTONSCHULZ 

List of valid keywords:

S_SQRT_ORDER {Integer} 

Order of the iteration method for the calculation of the sqrt of S.  
This keyword cannot be repeated and it expects precisely one integer.  
Default value:
3 

Alias names for this keyword: SIGN_SQRT_ORDER 
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