Section RI_METRIC

• Sets up RI metric

• Section path: CP2K_INPUT / ATOM / METHOD / XC / WF_CORRELATION / RI / RI_METRIC

• This section cannot be repeated.

• Subsections

  • none

• Keywords

  • CUTOFF_RADIUS
  • EPS_RANGE
  • OMEGA
  • POTENTIAL_TYPE
  • T_C_G_DATA

• Keyword descriptions

  CUTOFF_RADIUS
  	CUTOFF_RADIUS {Real}
  	The cutoff radius (in Angstrom) for the truncated Coulomb operator.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 3.00000000E+000
  	Default unit: [angstrom]

  EPS_RANGE
  	EPS_RANGE {Real}
  	The threshold to determine the effective range of the short range RI metric: erfc(omega*eff_range)/eff_range = EPS_RANGE
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-008

  OMEGA
  	OMEGA {Real}
  	The range parameter for the short/long range operator (in 1/a0).
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+000

  POTENTIAL_TYPE
  	POTENTIAL_TYPE {Keyword}
  	Decides which operator/metric is used for resolution of the identity (RI).
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: DEFAULT
  	List of valid keywords: COULOMB Coulomb metric: 1/r. Recommended for RI-MP2, DEFAULT Use Coulomb metric for RI-MP2 and normal-scaling RI-SOS-MP2, RI-RPA and GW. Use Overlap metric for low-scaling RI-SOS-MP2, RI-RPA and GW for periodic systems. Use truncated Coulomb metric for low-scaling RI-SOS-MP2, RI-RPA and GW for non-periodic systems. IDENTITY Overlap metric: delta(r). LONGRANGE Longrange metric: erf(omega*r)/r. Not recommended with DO_SVD .TRUE. SHORTRANGE Shortrange metric: erfc(omega*r)/r TRUNCATED Truncated Coulomb metric: if (r < R_c) 1/r else 0. More accurate than IDENTITY for non-periodic systems. Recommended for low-scaling methods.

  T_C_G_DATA
  	T_C_G_DATA {Word}
  	Location of the file t_c_g.dat that contains the data for the evaluation of the truncated gamma function
  	This keyword cannot be repeated and it expects precisely one word.
  	Default value: t_c_g.dat