Section OPT_RI_BASIS

• Parameters influencing the optimization of the RI MP2 basis. Only exponents of non-contracted auxiliary basis can be optimized. An initial RI auxiliary basis has to be specified.

• Section path: CP2K_INPUT / ATOM / METHOD / XC / WF_CORRELATION / OPT_RI_BASIS

• This section cannot be repeated.

• This section cites the following reference: [DelBen2013]

• Subsections

  • none

• Keywords

  • BASIS_SIZE
  • DELTA_I_REL
  • DELTA_RI
  • EPS_DERIV
  • MAX_ITER
  • NUM_FUNC

• Keyword descriptions

  BASIS_SIZE
  	BASIS_SIZE {Keyword}
  	Specifies the size of the auxiliary basis set automatically generated as initial guess. This will be effective only if RI_AUX_BASIS_SET in the KIND section and NUM_FUNC are not specified.
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: MEDIUM
  	List of valid keywords: LARGE Without description, yet. MEDIUM Without description, yet. VERY_LARGE Without description, yet.

  DELTA_I_REL
  	DELTA_I_REL {Real}
  	Target accuracy in the relative deviation of the amplitudes calculated with and without RI approximation, (more details in Chem.Phys.Lett.294(1998)143).
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-06
  	Alias names for this keyword: DI_REL

  DELTA_RI
  	DELTA_RI {Real}
  	Target accuracy in the absolute difference between the RI-MP2 and the exact MP2 energy, DRI=ABS(E_MP2-E_RI-MP2).
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 5.00000000E-06
  	Alias names for this keyword: DRI

  EPS_DERIV
  	EPS_DERIV {Real}
  	The derivatives of the MP2 energy with respect to the exponents of the basis are calculated numerically. The change in the exponent a_i employed for the numerical evaluation is defined as h_i=EPS_DERIV*a_i.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-03
  	Alias names for this keyword: EPS_NUM_DERIV

  MAX_ITER
  	MAX_ITER {Integer}
  	Specifies the maximum number of steps in the RI basis optimization.
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 50
  	Alias names for this keyword: MAX_NUM_ITER

  NUM_FUNC
  	NUM_FUNC {Integer} ...
  	Specifies the number of function, for each angular momentum (s, p, d ...), employed in the automatically generated initial guess. This will be effective only if RI_AUX_BASIS_SET in the KIND section is not specified.
  	This keyword cannot be repeated and it expects a list of integers.
  	Default value: -1