Section SPLINE

• specifies parameters to set up the splines used in the nonboned interactions (both pair body potential and many body potential)

• Section path: CP2K_INPUT / FORCE_EVAL / MM / FORCEFIELD / SPLINE

• This section can be repeated and can be optional.

• Subsections

  • none

• Keywords

  • EMAX_ACCURACY
  • EMAX_SPLINE
  • EPS_SPLINE
  • NPOINTS
  • R0_NB
  • RCUT_NB
  • UNIQUE_SPLINE

• Keyword descriptions

  EMAX_ACCURACY
  	EMAX_ACCURACY <REAL>
  	Specify the maximum value of energy used to check the accuracy requested through EPS_SPLINE. Energy values larger than EMAX_ACCURACY generally do not satisfy the requested accuracy
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 2.00000000E-02
  	Default unit: [hartree]

  EMAX_SPLINE
  	EMAX_SPLINE <REAL>
  	Specify the maximum value of the potential up to which splines will be constructed
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 5.00000000E-01
  	Default unit: [hartree]

  EPS_SPLINE
  	EPS_SPLINE <REAL>
  	Specify the threshold for the choice of the number of points used in the splines (comparing the splined value with the analytically evaluated one)
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-07
  	Default unit: [hartree]

  NPOINTS
  	NPOINTS 1024
  	Override the default search for an accurate spline by specifying a fixed number of spline points.
  	This optional keyword cannot be repeated and it expects precisely one integer.
  	Default value: -1

  R0_NB
  	R0_NB <REAL>
  	Specify the minimum value of the distance interval that brackets the value of emax_spline.
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: 4.76259488E-01
  	Default unit: [angstrom]

  RCUT_NB
  	RCUT_NB {REAL}
  	Cutoff radius for nonbonded interactions. This value overrides the value specified in the potential definition and is global for all potentials.
  	This optional keyword cannot be repeated and it expects precisely one real.
  	Default value: -1.00000000E+00
  	Default unit: [angstrom]

  UNIQUE_SPLINE
  	UNIQUE_SPLINE <LOGICAL>
  	For few potentials (Lennard-Jones) one global optimal spline is generated instead of different optimal splines for each kind of potential
  	This optional keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.