Section BUCK4RANGES

• This section specifies the input parameters for the Buckingham 4-ranges potential type. Functional form:
  • V(r) = A*EXP(-B*r) for r < r₁
  • V(r) = Sum_n POLY1(n)*rⁿ for r₁ ≤ r < r₂
  • V(r) = Sum_n POLY2(n)*rⁿ for r₂ ≤ r < r₃
  • V(r) = -C/r⁶ for r ≥ r₃

• Section path: CP2K_INPUT / FORCE_EVAL / MM / FORCEFIELD / NONBONDED / BUCK4RANGES

• This section can be repeated.

• Subsections

  • none

• Keywords

  • A
  • ATOMS
  • B
  • C
  • POLY1
  • POLY2
  • R1
  • R2
  • R3
  • RCUT
  • RMAX
  • RMIN

• Keyword descriptions

  A
  	A {Real}
  	Defines the A parameter of the Buckingham potential
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [K_e]

  ATOMS
  	ATOMS {Word} {Word}
  	Defines the atomic kind involved in the nonbond potential
  	This keyword cannot be repeated and it expects precisely 2 words.

  B
  	B {Real}
  	Defines the B parameter of the Buckingham potential
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom^-1]

  C
  	C {Real}
  	Defines the C parameter of the Buckingham potential
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom^6*K_e]

  POLY1
  	POLY1 {Real} ...
  	Coefficients of the polynomial used in the second rangeThis keyword can be repeated several times.
  	This keyword can be repeated and it expects a list of reals.
  	Default unit: [K_e]

  POLY2
  	POLY2 {Real} ...
  	Coefficients of the polynomial used in the third rangeThis keyword can be repeated several times.
  	This keyword can be repeated and it expects a list of reals.
  	Default unit: [K_e]

  R1
  	R1 {Real}
  	Defines the upper bound of the first range
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]

  R2
  	R2 {Real}
  	Defines the upper bound of the second range
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]

  R3
  	R3 {Real}
  	Defines the upper bound of the third range
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]

  RCUT
  	RCUT {Real}
  	Defines the cutoff parameter of the Buckingham potential
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E+01
  	Default unit: [angstrom]

  RMAX
  	RMAX {Real}
  	Defines the upper bound of the potential. If not set the range is the full range generate by the spline
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]

  RMIN
  	RMIN {Real}
  	Defines the lower bound of the potential. If not set the range is the full range generate by the spline
  	This keyword cannot be repeated and it expects precisely one real.
  	Default unit: [angstrom]